Full opinion text
FUENTES, Circuit Judge: Table of Contents I. Facts & Posture.........................................................233 A. Factual Background...................................................233 1. The Defendants...................................................233 2. The Plant........................................................234 B. Clean Water Act Violations.............................................234 1. Unlawful Discharge of Wastewater..................................235 2. Resulting Oil Spills & Ensuing Investigations.........................236 C. Clean Air Act Violations...............................................238 1. The Plant’s CAA Permits...........................................238 2. Burning Excess Paint..............................................239 D. OSHA Incidents......................................................240 1. The Coxe Fatality.................................................240 2. The Marchan Incident.............................................241 3. The Owens Incident...............................................242 4. The Velarde Incident..............................................243 E. Indictment...........................................................244 F. Pre-Trial Issues......................................................245 G. Trial & Sentencing....................................................245 H. The Present Appeal & the Parties’ Arguments............................246 II. Discovery Issues.........................................................247 A. Pre-Trial Discovery in a Criminal Case..................................247 1. Jencks Material...................................................247 2. Fed.R.Crim.P. 16..................................................248 3. Brady and Giglio Material..........................................249 B. Pre-Trial Discovery in this Case........................................249 C. The Scope of Fed.R.Crim.P. 16(a)(1)(C)..................................251 1. Applicable Standard of Review......................................251 2. Rule 16(a)(l)(C)(ii).................................................252 III. Jury Instructions on the Clean Water Act Violations........................255 A. Negligence Instruction Under the Clean Water Act.......................255 1. Invited Error Doctrine.............................................256 B. The District Court’s Refusal to Define “Recklessness”.....................260 1. Accuracy of the Court’s Instructions on “Knowing” Conduct............261 2. Abuse of Discretion in Rejecting Proposed Language..................262 IV. Mutually Exclusive Verdicts..............................................263 V. Conclusion..............................................................267 Following an eight-month criminal trial, a jury convicted Atlantic States Cast Iron Pipe Company and four of its managers of various crimes. These included conspiring to commit a host of environmental pollution and worker safety violations, attempting to cover up or impede federal investigation of those violations, and substantive violations of the Clean Water Act and the Clean Air Act. Specifically, the Defendants were found to have illegally pumped contaminated water into storm drains and, as a result, into the Delaware River; to have unlawfully burned 50-gallon drums of paint waste in a cupola and emitted the fumes from those activities into the air; and to have attempted to cover up several work-related accidents at its facility, one of which resulted in the death of an employee. The jury also found that the Defendants engaged in a conspiracy to commit these acts — and to impede the resulting federal investigation — in order to maximize productivity and profits at the Plant. The Defendants appealed from the jury’s verdict, raising a litany of issues relating to pre-trial discovery, the District Court’s handling of the trial itself, the propriety of certain jury instructions, and the District Court’s sentencing determinations. For the reasons that follow, and in light of the District Court’s fine handling of these extraordinarily complicated proceedings, we will affirm the final judgments of conviction and sentence in this case. I. Facts & Posture A. Factual Background 1. The Defendants Atlantic States Cast Iron Pipe Company (the “Company”), owned by McWane, Inc., operates a pipe foundry in Phillipsburg, New Jersey. The Plant, which produces ductile iron pipes used as municipal water pipes, sits on a 33-acre facility located just one mile from the Delaware River. Prior to 2002, the facility had several large storm drains that flowed through the municipal storm sewers to an outfall pipe that fed into the Delaware River. During the periods in question, the Plant was overseen by John Prisque, who became the Plant Manager in 1998. Prior to that, Prisque served as the Production Superintendent and the Production Manager. Jeffrey Maury, like Prisque, had a long career at the Plant. After serving as the Maintenance Foreman from 1995 to 1997, Maury was promoted to Maintenance Superintendent in 1998. In this position, Maury oversaw the maintenance of all equipment used in the casting and finishing of the Company’s pipes and of construction equipment, such as forklifts. He also supervised all of the Plant’s maintenance foremen. Maury reported directly to Prisque. All finishing processes at the Plant, including the cement lining and pipe painting operations, were overseen by Craig Davidson, who served as the Finishing Superintendent beginning in March 1998. Like Maury, Davidson reported directly to Prisque. Scott Faubert served as the Plant’s Human Resources Manager from 1996 to September 2000. His job responsibilities included overseeing the Plant’s health and safety programs and supervising the Plant’s Safety Director. Faubert also reported directly to Prisque. 2. The Plant As part of the Company’s production process, employees at the Plant melt scrap iron and steel at an extremely high heat in a cupola, or furnace. The molten metal is then poured into a pipe cast and passed through an oven that makes the pipes ductile. From there, the pipes are sent to the finishing department, where they are cooled with water, grinded, pressure tested, lined with cement, rinsed and painted. Much of the machinery used during this process relies on hydraulic cylinders and petroleum-based hydraulic fluid. This process produces contaminated water and air pollutants, which are governed by the Clean Water Act, 33 U.S.C. § 1251 et seq., and the Clean Air Act, 42 U.S.C. § 7401 et seq., respectively. Discharges of any such contaminated water and emissions of any such air pollutant are controlled by strict permits issued to the Company by the relevant policing agency. As an industrial facility, the Plant is also subject to the requirements of the Occupational Health and Safety Act, as administered by the Occupational Health and Safety Administration (“OSHA”). See 29 U.S.C. § 651 et seq. OSHA has promulgated volumes of regulations designed to ensure that workers can perform their jobs without substantial risk of industrial accident. Under OSHA’s regulations, the Plant is required to comply with certain health and safety standards, educate employees about workplace safety, and report any on-the-job injuries. Certain categories of workplace injuries, including those involving a fatality or the risk of an ongoing imminent danger at a facility, are subject to investigation by a regional OSHA inspector. The Defendants in this case were charged with and convicted of conspiring to violate these regulatory schemes and to impede federal investigations into those violations. They were also separately charged with and convicted of several of the underlying violations. The sections that follow describe these violations in turn. B. Clean Water Act Violations Congress enacted the Clean Water Act (the “CWA”) to preserve the environmental and physical integrity of the national waterways. 33 U.S.C. § 1251. To that end, the CWA “prohibits the discharge of any pollutant into waters of the United States except as expressly authorized.” United States v. Allegheny Ludlum Corp., 366 F.3d 164, 171 (3d Cir.2004). Chemical or industrial waste constitutes a pollutant. 33 U.S.C. § 1362(6). An individual wishing to discharge such a substance must first obtain a National Pollution Discharge Elimination System permit (a “discharge permit”) from the relevant agency overseeing the program — in this case, the New Jersey Department of Environmental Protection (“NJDEP”). Any discharge must comply with the terms of the permit, and the restrictions set out in the CWA. Id. § 1342(k). The Company held a discharge permit that fundamentally allowed the Plant to discharge two types of substances: (1) storm water runoff {e.g., rainwater); and (2) “non-contact cooling water” — i.e. water that has not come into contact with any industrial machinery or its associated pollutants. ACL States, 2007 WL 2282514, at *14. To qualify as “non-contact ■ cooling water,” the discharged water could have no visible sheen, had to pass tests designed to measure petroleum hydrocarbon levels, and could contain no solid debris. At no point was the Company permitted to discharge wastewater created from the cleaning of equipment, the pipes produced in the Plant, or the Plant’s facilities. 1. Unlawful Discharge of Wastewater The Plant uses large volumes of water at several stages of its manufacturing process, producing both noncontact cooling water and wastewater. During the relevant time periods, water was pumped from large containment tanks through the Plant via a closed-loop system, and was used to cool the pipes after casting, to cool -the casting machines themselves and to cool the cupola. The Plant also used water to rinse the pipes during the cement lining process and afterward, prior to painting. Both processes yielded non-dischargeable wastewater. a) The Number Four Pit While some of the cooling water burned off as steam, the Plant’s cooling processes — the casting process in particular — also generated wastewater. During the casting process, the water used to cool the pipes dripped from the closed-loop recirculation system into a pit — referred to as the Number Four Pit — located beneath the casting machine. Because the machines also dripped hydraulic oil into the pit, the water in the Number Four Pit was often contaminated. The Number Four Pit was positioned adjacent to the “bull ladle pit,” in which molten iron from the cupola was hel'd, and had to be watched carefully to ensure that it did not overflow into the bull ladle pit and cause an explosion. Workers testified that the pit was typically full and that the need to drain the pit varied day to day, depending on the severity of the leaks from the machinery above. To drain the Number Four Pit, workers were supposed to pump the wastewater through trenches that ran alongside the casting equipment and into large holding tanks located outside the building. However, both' during production and during the night-shift maintenance activities, the workers were instructed to pump into the tanks even if the tanks were too full to handle more wastewater. The result of this pumping was that the tanks overflowed, sending “dark, hot, muddy water” flowing down the roadway alongside the Plant, and into the nearby storm drains. Id. at *118. Night-shift employees were also sometimes instructed to pump the water out of the pit and directly onto the ground outside the Plant. Though the frequency of this pumping depended on how much the machinery leaked in a given day, employees estimated that the discharges from the Number Four Pit occurred once or twice a week. Robert Bobinis, who worked in the casting area of the Plant, noted that he mentioned the overflow problem to Maury one day and told Maury, “I’m not going to jail for this.” Maury responded only with, “Shhh.” Id. at *120. b) The Cement Pit Like the Number Four Pit, the Cement Pit suffered from too much wastewater and too little storage. Water from the Plant’s cement washing process gathered in containment pits below the cement lining equipment and then flowed, via trenches or troughs, to the Cement Pit located outside the building. Along the way, this water collected the cement debris and hydraulic oil that had accumulated during the manufacturing process. Once in the pit, the debris sunk to the bottom and the oil floated to the top. As a result of these pollutants, water in the cement pits had a greenish, oily appearance. During production, this wastewater remained in the pit. The oil was supposed to be skimmed from the top of the water, and the water itself recycled through the Plant and reused for cement washing. However, over time, the debris at the bottom of the pit would accumulate and displace the water in the pit, until it began to interfere with production. This required that the pit water be removed, usually at the end of the production week, so that maintenance workers could scrape the bottom of the pit of debris. Workers were supposed to clean the pit by pumping the water out and into hazardous materials tanks that were maintained and emptied by outside contractors. In 1999, the Plant altered this system, installing next to the pit a large, brown tank specifically intended to hold the water during cleaning and allow for its reuse afterward. When the tank was full, workers were to pump any excess water into the preexisting hazardous materials tank, located across the roadway, for disposal. In reality, however, these practices were routinely disregarded in favor of illegally pumping the wastewater onto the roadway and, as a result, into the facility’s storm drains. During the night-shift and, in particular, on Friday nights, maintenance workers were instructed to “pump the pit” by emptying the wastewater onto the nearby roadway. Id. at *102. After the pit was emptied, workers put the pumps away and cleared the debris from the bottom of the pit. They then re-filled the pit with water so that production could resume during the morning shift. Employees testified that some of these orders came directly from Davidson, the head of the Finishing Department. Other employees testified that they received their orders from their shift foreman. As with the discharges from the Number Four Pit, this water flowed from the roadway into the nearby storm drains and, eventually, into the Delaware River. This practice appears to have continued until February 2000, when environmental inspectors began looking into possible spills from the Plant. At that point, workers began pumping the cement pit water into the hazmat tanks. However, because that pit was frequently full, the cement water still occasionally spilled over the sides of the hazmat pit, down the roadway to the storm drains and, eventually, into the river. 2. Resulting Oil Spills & Ensuing Investigations The unpermitted discharges from the Plant resulted in at least three separate oil spills on the Delaware River. Statements made by the individual defendants to the state and federal investigators looking into these spills would later serve as the basis for some of the false statements and obstruction charges in the indictment. a) March 1998 On March 19, 1998, New Jersey residents reported seeing an oil slick on the Delaware River. An employee of the Phillipsburg Department of Public Works investigated and traced the spill to a large outfall pipe in the vicinity of the Plant. The discharge was eventually traced to the facility itself. The local agency sent the Company a letter, copied to the NJDEP, requesting that the facility take measures to avoid such spills going forward. b) December 1999 On December 5, 1999, another local resident noticed a large sheen of oil — later estimated to contain approximately 200-300 gallons of liquid petroleum — floating on the Delaware River. The resident reported the sighting to local authorities, which again triggered an investigation. Local authorities contacted Bruce Doyle, an emergency response specialist for the NJDEP, who began by visiting the location at which the sheen was spotted. He took photographs and collected samples of the water, and noted that he believed the discharge had been continuing for some time based on the amount of oil that he observed in the river. Doyle traced the discharge to an outfall pipe near the Plant. Later that same day, Doyle and the Chief of the Phillipsburg Fire Department, Richard Hay, went to the Company’s facility, where they were initially denied entry. While waiting outside the facility’s gates, Doyle observed large, oily puddles on the ground inside the gates. He could also see discharge flowing into two storm drains, one of which was near what he later learned to be the cement pit. He also observed a “partially-submerged sump pump that was not operating at the time.” Id. at *111. Doyle testified that it appeared to him that the water flowing into the drains had come from the exposed end of the sump pump lying on the roadway. Once allowed into the facility, Doyle confirmed that the cement containment pond was the source of the discharge he had observed at the outfall. Doyle also had an opportunity to speak with Joseph Mad-dock, the Plant’s safety director, who reported directly to Faubert.1 Maddock said he had no information on the sump pump or hose in the pit and told Doyle that “he had no idea what had caused the discharge.” Id. at *112. Doyle told Mad-dock that the Company was directed to clean up the spill at the Plant and at the outfall. NJDEP officials obtained a search warrant to examine the facility, and returned to the Plant on February 24, 2000. They were accompanied by officers from the New Jersey Department of Law and Public Safety, Christopher Fernicola and Jeffrey Hill; and FBI Special Agent James Spence. Doyle was also present. At that time, the cement pit’s condition was again full of debris, oil and milky-green water, and was fuller than it had been on December 5. Investigators collected a sump pump and hose, not in use, from around the pit and took those items into evidence. Investigators also took photographs of the area and sampled water from the pit. Later tests confirmed that the liquid in the pit matched the liquid that had flowed through the storm drains and into the Delaware River. During this visit, officials interviewed Maury, Davidson and Prisque. Agents Fernicola and Hill interviewed Maury. Maury told them that he thought the leak had been caused by a leak in the hydraulic line on one of the street sweeper trucks used at the Plant. Agent Fernicola testified that Maury fidgeted in his chair and wrung his hands throughout the interview. Davidson told Agent Hill that the discharge was caused by a hole in the hose that led from the sump pump to the storage tank where the water was held before being recirculated through the system. Like Davidson, Prisque attributed the discharge to a hole in the sump pump hose. c) April 2000 On April 16, 2000, Doyle was again called to investigate reports of a floating oil sheen on the Delaware River. This sheen was smaller, but was still visible from the road. Doyle again traced the spill back to the outfall pipe near the Company’s facility, this time observing oil and a “cement-like material” in the discharge. Id. at *113. Doyle went to the Plant later that day and noted that, though there had been rainfall that day, the roads surrounding the Plant did not have puddles and were dry, indicating that the oil discharge had not been caused by surface rainfall washing the oil from the ground into the drain. He also observed a large oil sheen surrounding a grated drain at the facility and concluded that drain had been the source of the sheen he observed on the river. The NJDEP again issued a directive and notice of violation against the Company. In light of these discharges and the oil spills, the Defendants — the Company, Maury, Davidson and Prisque — were eventually charged with violations of the Clean Water Act § 1319(c). They were also charged with lying to investigators about the source of the 1999 spill. C. Clean Air Act Violations The Clean Air Act (the “CAA”), overseen by the EPA but administered at the local level by the NJDEP, provides that “certain stationary sources of air pollution must obtain federal operating permits” prior to any emissions. Ocean Cnty. Landfill Corp. v. United States EPA, 631 F.3d 652, 654 (3d Cir.2011) (citing 42 U.S.C. §§ 7661-7661 f, 7661 a(d)(l), 40 C.F.R. § 70, App. A). Because the Company’s manufacturing process involves the smelting of metals in a cupola, it was required to obtain and comply with an NJDEP-issued emissions permit. 1. The Plant’s CAA Permits The Plant’s cupola, which was approximately 70 to 80 feet high, required the use of various fuels in order to heat or “charge” the furnace to a temperature high enough to melt scrap metal to make the cast iron pipes. The Company held operating permits at all times relevant to this case. In addition to regulating how the emissions were to be measured and reported to the NJDEP, the operating permits also governed what fuels could be sent into the cupola and what amount of pollutant emissions could be released into the air. Under the relevant permits, the Company could use only certain types of fuel. The Plant typically used coke, but was also permitted to use non-hazardous waste paint in limited amounts. At all times relevant to this case, the Plant was permitted to burn no more than 55 gallons of nonhazardous waste paint per day. No material other than a permissible fuel and the scrap metal being melted were to be burned in the cupola. In particular, hazardous waste paint — essentially, fresh, liquid paint — was never a permitted fuel, since it releases higher levels of volatile organic chemicals when burned. As for the Plant’s emissions levels, the Company was permitted to release from the cupola’s stack no more than 2,500 parts per million of carbon monoxide per hour, averaged over the course of a day. Three times per quarter, the Company was permitted to burn up to 4,000 parts per million of carbon dioxide per hour, averaged over the course of a day. Any amount beyond these levels, termed an “exceedance,” was in violation of the Plant’s operating permit and had to be reported to the NJDEP. Atl. States, 2007 WL 2282514, at *124. The Plant had a long, documented history of failure to comply with these limitations and, as of late 2000, was facing fines of approximately $600,000 for documented exceedances. Prisque would have known about these exceedances and any others because, as Plant Manager, he was responsible for certifying the Plant’s compliance and exceedance reports to the NJDEP. 2. Burning Excess Paint The pipe finishing process, during which the pipes were painted inside and/or outside, generated large volumes of waste paint. The Plant’s disposal method for this waste, at least in part, was to burn it in the Plant’s cupola in violation of the Company’s operating permit. As automated machines spray painted each pipe, excess paint dripped and collected on the floor below the paint machine, forming a thick, tarry coating. During the night shift, once production had stopped, workers used flat shovels to scoop the waste paint into 55-gallon drums, generally filling them 2-8 inches from the top of the drum. Some employees testified that they also placed paint-covered plastic drop cloths — not permitted in the cupola — in the drums. The workers then placed small pieces of iron called “chill” in each drum so that the crane, which used a magnet to lift things, could lift them. The workers then sealed the drums, duct taped the seam of the lid and moved the drums to the scrap yard. Employee testimony at trial demonstrated that these drums of waste paint frequently were burned in the cupola. After placing the drums in the scrap yard, cranes would lift the drums into the cupola and burn them. In addition to waste paint, the drums often contained the plastic tarps on which the paint had gathered under the painting station. Employees of the Plant testified that Davidson instructed them to handle the paint in this way, that he did so specifically when the drums started to build up in the scrap yard, and that workers filled and moved somewhere between four and ten drums per night. The Plant disposed of waste paint this way as early as 1999, burning an average of four drums a day. NJDEP officials first spotted large colléctions of 55-gallon drums in the scrap yard in February 2000, while they were exécuting the search warrant to investigate the 1999 wastewater discharge into the Delaware River. Officials photographed the drums, some of which were sealed and others of which were open, exposing a black, tarry substance. Going forward, the Company made efforts to hide any existing drums from state officials when they visited the Plant, or to dispose of them prior to the officials’ arrival. One crane operator testified that, in anticipation of an expected NJDEP visit in 2003, his supervisor told him to put one 55-gallon drum of paint per hour into the cupola. When the crane would not lift some of the drums, he was told to bury them in scrap metal so that they would not be visible. George Shepherd, the former General Electrical Foreman and a key government witness at trial, testified that this incident occurred around April 2003. He explained that this was fairly standard practice any time “visitors” came to the facility. Prisque would instruct them to “make sure there’s nothing out in the plant they could find.” Id. at *128. Shortly after the NJDEP inspectors visited, Prisque directed Shepherd to get rid of the drums that had been buried. Shepherd said that the Plant burned approximately 20 55-gallon drums of waste paint in the cupola that day, and another 15-20 drums the next. Moreover, both the workers and their supervisors understood that burning the paint in the cupola was causing the Plant to exceed the emissions cap in its operating permit. Shepherd testified that he reported this concern to Prisque in 2003, after the aforementioned incident, but that Prisque told him that the paint had nothing to do with the meter readings and said, “Don’t go there.” Atl. States, 2007 WL 2282514, at *128. In light of these practices, Prisque and the Company were eventually charged with violating the Clean Air Act between February and August 2003. D. OSHA Incidents Between 1999 and 2002, several of the Company’s employees suffered severe injuries at the Plant due to unsafe working conditions. The evidence introduced at trial demonstrated that the Company’s management took steps to conceal the cause of those injuries and to obstruct OSHA investigators’ inquiries. 1. The Coxe Fatality On March 24, 2000, Al Coxe, an employee at the Plant, was run over and killed by a forklift driven by Juan De Los Santos. De Los Santos had never been trained, as required, on the forklift and this was his second accident. OSHA officials were notified of the accident, as required by law. Safety Compliance Officer Carol Tiedeman was assigned to investigate the facility and arrived that same morning. Faubert, the Human Resources Manager and the individual in charge of overseeing safety at the Plant, met with Tiedeman and showed her the scene of the accident. Faubert informed Tiedeman that the forklift driver had not been properly trained on the equipment. He also showed her the forklift — referred to as forklift # 24— which appeared to be working properly, and assured Tiedeman that it had been untouched since the accident. As she was leaving the facility that day, Tiedeman instructed Faubert to gather any inspection sheets for the forklift. She recommended that Faubert have the forklift completely inspected before it be used again. When Tiedeman returned to the Plant on April 7, 2000, she met with Faubert and his subordinate, Joe Maddock, the employee charged with maintaining the Plant’s OSHA injury log. She was given an inspection report, dated the day after the Coxe accident, which noted that Maury and Yukna, the garage mechanic, had ñispected forklift # 24 and found it to be in “perfect operating condition.” Id. at *77. In later visits to the Plant, however, Tiedeman was given the opportunity to review several drivers’ maintenance checklists for forklift # 24 from immediately before and immediately after the accident. Almost all of those checklists noted extensive problems with the forklift, including that the brakes were defective. Moreover, the forklift’s repair logs showed no work performed on the forklift, suggesting that it could not have been in “perfect” condition during or immediately after the Coxe accident. Id. Indeed, despite Faubert’s representations to the contrary, later investigations demonstrated that the Company’s management had concealed the fact that the brakes on forklift # 24 had not been functioning at the time that Coxe was run over, and that this was the cause of the accident. As a general matter, testimony and equipment records from the Plant demonstrated that the Plant’s forklifts were often in disrepair, with brake failure being one of several recurring maintenance problems. Forklift operators repeatedly reported problems with the machines, but were told to drive the equipment or risk losing their jobs. These forklift operators testified that, in order to make do, they routinely brought their own brake fluid to work, and many learned how to drop the forklift’s load in order to stop the machine without brakes. In fact, forklift # 24 had been reported as having brake problems during the shift immediately prior to the fatal accident. Shepherd testified that, just after Coxe’s death, Prisque told Maury to have Shepherd take forklift # 24 to the maintenance area for inspection. There, Shepherd and Maury confirmed that the brakes had malfunctioned. Shepherd instructed Yukna to fix the problem. When Shepherd saw the forklift later that morning, around the time of the OSHA visit, he noted that the brakes were working again and assumed they had been fixed. At some point during the morning, Prisque also held a meeting with Maury, Davidson, Shepherd, and two others. Shepherd said that, at this meeting, he was instructed to make preparations for the inevitable OSHA visit, which might include a walk through the facility. Robert Rush, another employee who testified at trial, stated that Prisque told him to lie about the condition of the forklift, and to tell OSHA investigators that “the forklift was fully operational, it was safe, and [De Los Santos] was driving recklessly.” Id. at *89. When Rush told Prisque that he did not want to lie, Prisque threatened him and said, “You’re going to tell them this because your job depends on it. It’s in the best interest of your employment. In the best interest of your job somewhere down the line.” Id. 2. The Marchan Incident Gabriel Marchan, a plant supervisor, was struck by a forklift driven by De Los Santos on April 27, 1999. Though the accident occurred in 1999, OSHA first learned about Marchan’s injury in 2000, while investigating the Coxe accident. There had been no prior investigation into the accident because Marchan’s injury had not been recorded, as required, in the Plant’s OSHA 200 logs — logs in which employers are required to record workplace injuries. In April 2000, while investigating the Coxe accident, Tiedeman read a news article which stated that the forklift driver who had run over Coxe had been involved in a similar incident at the Plant the year before. When Tiedeman asked Faubert about this incident, he chuckled and stated that Marchan’s leg had been broken. Tiedeman requested a copy of Marchan’s accident report. The evidence presented at trial demonstrated that the Defendants thereafter took steps to conceal the extent of Marchan’s injuries from OSHA. In May 2000, Faubert provided Tiedeman with a statement from Marchan that stated falsely that he had come back to work the day following the accident. When Tiedeman, confused, asked about the broken leg, Faubert changed his story and said that there had been no broken leg. When Tiedeman asked why the injury had not been recorded, as required, Faubert again stated that this was because the leg had not been broken and because Marchan had returned to work the next day. In light of these discrepancies, Officer Tiedeman opted to interview Marchan directly. Marchan testified that, just before his interview with Tiedeman in July 2000, Faubert threatened to fire him unless he lied about his injuries. Marchan thus told Tiedeman that he had been struck and run over by a forklift, but that he had only sustained a scratch and a bruise as a result. He denied having been seriously injured. That same day, Tiedeman also interviewed Faubert and his subordinate, Mad-dock, regarding the Plant’s failure to log the Marchan accident. Maddock stated that he understood that OSHA required employers to report employees’ on-site injuries and any restrictions on their ability to work, and said that it was his job to decide whether to include an injury in the OSHA log, based on the description of that injury in the Plant’s own first aid log. Maddock denied having been at the Plant on the day that Marchan was run over. When Tiedeman asked Maddock why Marchan’s injury had not been recorded and whether Marchan had missed any work because of it, Faubert interjected that Marchan had not been treated at the plant and that, as a result, no OSHA log entry was made. It was only later, in reviewing subpoenaed company records that Officer Tiedeman learned that Faubert, Maddock and Marchan had lied to her. Despite their representations to the contrary, Marchan had been seriously injured and placed on restricted duty for 44 days following his accident. Indeed, Marchan testified that, immediately after the accident, it was Maddock who had driven him to the hospital for treatment. After his leg had been placed in a splint, and despite his pleas that he be allowed to go home because he was in pain, it was also Maddock who drove him back to the Plant and forced him to sit in a chair and paint from a bucket for the rest of the day. During the remainder of the time that his leg was in a cast, another employee drove him to and from work. The Company had an obligation to report Marchan’s injury, and the fact that he was limited to restricted duty for the month and a half after his accident, to OSHA but had failed to do so. 3. The Owens Incident On June 25, 1999, employee Robert Owens was injured and lost his eye when a piece of a rotating blade from the cut saw he was using broke off from the blade and struck him in the face. OSHA compliance officer Alex Salerno was assigned to investigate the incident and to assess whether adequate safety features had been in place at the time of Owens’ injury. Salerno visited the Plant roughly two weeks after Owens’ accident, met with Faubert and was escorted to the site of the accident. At that time, he witnessed a worker operating the machine from behind a sliding plexiglass shield with a wooden frame and a wire mesh screen' that was designed to protect the worker. ■ Salerno observed that the shield appeared to have been newly built, but Faubert assured him that it had existed in that condition for 16 years. The employee at the machine told Salerno the shield had been in place for 10 years. Despite these representations, evidence and testimony at trial indicated that no wire mesh safety shield had been in place on the day of Owens’ accident. Rather, the plexiglass and wire mesh covering had been built by a carpenter a few days after Owens’ injury. The employee who told Salerno otherwise later testified at trial that Prisque instructed him to say that the shield “was always there” and that he lied to Officer Salerno because he wanted to keep his job. Id. at *84. 4. The Velarde Incident Attempts to conceal deficient safety measures and employee injuries were made again in December 2002, after Hector Velarde lost three fingers in a cement mixer accident. Velarde was cleaning the mixer on December 7, 2002, when his coworker activated the mixer without alerting him. When the mixer’s blades activated, Velarde’s fingers were amputated. Officer Tiedeman was the OSHA inspector assigned to investigate Velarde’s injury. On Tiedeman’s first visit to the Plant to investigate this incident, she met with Prisque, Don Harbin, the Plant’s maintenance manager, and Mark Neetz, then the Plant’s safety director. All three individuals escorted her to the mixer, and Harbin explained what had happened during the accident. When Tiedeman asked whether the machine had come with a safety switch or interlock switch — designed to shut down the machine if the doors were open — she was assured that it had not, but was told the Plant would attempt to install one itself. In truth, the mixer had come from the manufacturer with an interlock switch installed, but Prisque had instructed Shepherd to bypass the switch because it slowed production. Shepherd testified that prior to Tiedeman’s arrival, at Prisque’s instruction, he had removed all evidence that he had bypassed the switch in the first place and had rigged the machine to look as though no interlock switch ever existed. Before Tiedeman’s second visit to the Plant, Shepherd reinstalled the original interlock switch in order to make it look like the Plant had taken steps to improve the safety of the mixer. Tiedemán only learned that the mixer actually had been manufactured and shipped to the Plant with a functioning interlock switch in February 2003, when she requested and reviewed the owner’s manual for the equipment. The manual explicitly warned of the risks of bypassing the safety feature. When she confronted Harbin with this discovery, he confessed that there had originally been a switch, but said that it had only functioned for a day or two before it got too dirty to operate properly. He also speculated that the switch had been removed by an employee no longer at the Company and said he could not provide a name for that individual. In light of these incidents, the Company, along with Faubert, Prisque, and Maury, were charged with lying to OSHA inspectors and with attempting to obstruct their investigation into the employees’ injuries. E. Indictment On December 11, 2003, a federal grand jury sitting in the District of New Jersey indicted Defendants Prisque, Faubert, Maury, Davidson and the Company on charges of conspiring, in violation of 18 U.S.C. § 371, to (1) knowingly discharge a pollutant into U.S. waters, without and in violation of a permit, in violation of the Clean Water Act, 33 U.S.C. §§ 1311(a) and 1319(c)(2)(A); (2) knowingly violate a requirement and prohibition of permits under the Clean Air Act, 42 U.S.C. § 7413(c); (3) defraud the United States by obstructing the lawful functions of the [OSHA] and the [EPA] in enforcing federal workplace safety and environmental laws and regulations; (4) make false statements in matters within the jurisdiction of OSHA, EPA and the [FBI], in violation of 18 U.S.C. § 1001; and (5) corruptly influence and obstruct the administration of law under a pending proceeding before OSHA, in violation of 18 U.S.C. §§ 1505 and 1515(b). D. Ct. Op. 2. The indictment also charged the defendants with committing, or aiding and abetting the commission of, substantive violations of the aforementioned laws. Maury was charged with making false statements to investigators concerning the December 4, 1999 oil spill (Count 3), the Coxe forklift accident (Count 5), and with obstructing the OSHA investigation into Coxe’s death (Count 9). He was also charged with substantive violations of the Clean Water Act for the pumping of the cement pit that resulted in the sheen on the Delaware River on December 5, 1999 (Count 27), and the Number Four Pit from May to October 1999 (Counts 28-33). Davidson, in addition to the conspiracy charge, was indicted for substantive violations of the CWA for the pumping of the cement pit from December 1998 to February 2000 (Counts 12-26), and for the pumping of the cement pit that resulted in the sheen on the Delaware River on December 5, 1999 (Count 27). Davidson was also charged with making false statements to investigators regarding that spill (Count 4). Prisque was charged with violating the CWA based on the pumping of the cement pit that resulted in the sheen on the Delaware River on December 5, 1999 (Count 27) and with a substantive violation of the Clean Air Act for his participation in the burning of the Plant’s waste paint in the cupola between February and August 2003 (Count 34). Prisque was also charged with making false statements to OSHA officers concerning the Owens accident (Count 8), and with obstruction of a federal investigation for his role in concealing evidence regarding the Coxe forklift fatality, Marchan’s forklift injury, and the Velarde accident (Counts 9-11). Faubert was charged with making false statements to OSHA officials concerning Marchan’s forklift accident (Count 7), obstructing the investigation of Marehan’s forklift accident (Count 10), and obstructing the investigation of the Coxe fatality (Count 9). The Company was also charged with numerous crimes, including making false statements regarding the 1999 oil spill (Counts 3-4), the Coxe fatality (Count 5), and the Marchan accident (Count 7). It faced obstruction charges for the attempts to conceal evidence of the Owens accident (Count 8) and the cause of Coxe’s death (Count 9), the extent of Marchan’s injury (Count 10), and the cause of Velarde’s cement mixer accident (Count 11). Prosecutors also charged the Company with violating the CWA for the pumping of the cement pit from December 1998 to February 2000 (Counts 12-26), the pumping of the cement pit that resulted in the sheen on the Delaware River on December 5, 1999 (Count 27), and the pumping of the Number Four Pit in 1999 (Counts 28-33). Finally, the Company was charged with violating the Clean Air Act (Count 34). F. Pre-Trial Issues Pre-trial discovery in this case was highly contentious. In May 2004, the Government sought (and eventually obtained) a protective order allowing it to defer production of otherwise discoverable statements by current and former employees of the Plant until 30 days before the start of trial. The Government based this request on allegations of workplace harassment and intimidation against Plant employees and their concern that witnesses would be penalized for cooperating with the prosecution or would be too intimidated to testify at all. G. Trial & Sentencing Trial began on September' 27, 2005. The United States called 50 witnesses— many of them employees of the Company — and three rebuttal witnesses. Among the employees who testified were five unindicted co-conspirators: Joseph Maddock, the former safety and human resources director of the Plant; Donald Harbin, the Plant’s maintenance manager; George Shepherd, the general electrical foreman; Tom Dalrymple, who supervised emissions controls at the cupola and reported directly to Prisque; and Steven Wayda, the union representative at the Plant. The Defendants began presenting their case on February 8, 2006 and called another 52 witnesses. All of the individual Defendants testified. Defendants moved for a judgment of acquittal at the close of the Government’s case, and at the end of the evidence. The Court reserved judgment and submitted all counts to the jury. The Court also submitted to the jury, at the Defendants’ request, the lesser included offense (not charged in the indictment) of a negligent — as opposed to knowing — violation of the Clean Water Act, 33 U.S.C. § 1319(c)(1)(A). Negligent violations of the Act constitute misdemeanors,' rather than felonies. Following these proceedings and after 10 days of deliberation, on April 26, 2006, the jury convicted the Defendants of almost all of the charges levied against them. Notably, though the Company was convicted of felony violations of the CWA for the 1999 spill on the Delaware River and the unpermitted pumping of the cement pit (Counts 12-26, 27), the jury concluded that Prisque, Maury and Davidson were guilty only of negligent violations for those incidents. The jury found the Company and Maury guilty of felony violation of the CWA for the unpermitted pumping of wastewater from the Number Four Pit (Counts 28-33). All Defendants were convicted of having knowingly and willfully engaged in a conspiracy to achieve the purposes set out in the indictment. Following the jury verdicts, the Defendants filed an omnibus post-trial brief that raised a multitude of challenges to the jury’s verdicts and to the District Court’s handling of the case. In August 2007, the District Court ruled on the Defendants’ post-trial motions, rejecting the majority of those challenges, but granting Rule 29 judgments of acquittal for insufficient evidence on the following: (1) one false statement charge against Faubert and the Company, for the jury’s failure to reach a verdict (Count 2); (2) one CWA charge against Davidson and the Company, concerning an alleged unlawful discharge of wastewater in September 1999 (Count 21); and (3) one CWA charge against Maury and the Company concerning an alleged unlawful discharge of wastewater in October 1999. The Court denied the Rule 29 motions as to all other counts of conviction. The District Court held sentencing hearings in April 2009. It sentenced Prisque to 70 months’ imprisonment, Faubert to 41 months’ imprisonment, Maury to 30 months’ imprisonment, and Davidson to 6 months’ imprisonment. As for the Company, the Court opted to apply the Alternative Fines Act (the “AFA”), 18 U.S.C. § 3571(c)(1), rather than the CWA and CAA, in imposing criminal penalties. Applying the AFA, the Court fined the Company the maximum penalty of $500,000 per violation on Count 1 (conspiracy), Counts 8-11 (obstruction), Counts 12-16 (CWA— cement pit discharge), Counts 28-32 (CWA — Number Four Pit discharge), and Count 34(CAA) for a total fine of $8 million dollars. It also sentenced the Company to 4 years’ probation, with a court-ordered monitor to ensure regulatory compliance going forward. The Defendants timely appealed to this Court in May 2009. H. The Present Appeal & the Parties’ Arguments Jointly, the Defendants raise a multitude of arguments, principal among them that (1) they were afforded inadequate pre-trial discovery under Rule 16 of the Federal Rules of Criminal Procedure, (2) the Government withheld substantial Brady and Giglio material and engaged in numerous acts of prosecutorial misconduct, and (3) the District Court erred in instructing the jury on the appropriate standard of mens rea for a negligent violation of the CWA. They also raise numerous challenges to the District Court’s handling of the proceedings themselves, including its evidentiary rulings and the adequacy of the voir dire. The Defendants’ individual claims on appeal are equally numerous. The Company, in addition to challenging the adequacy of the Rule 16 discovery it received, argues that the District Court erred in denying its motions for acquittal and for a new trial. It also challenges the reasonableness of the criminal penalties imposed by the District Court under the AFA. Faubert contests the sufficiency of the evidence used to convict him; argues that there was a fatal duplicity in the charged objectives of the conspiracy, and challenges the sentence imposed by the District Court. Davidson argues that the verdicts against him for conspiracy and for negligent violation of the Clean Water Act are mutually exclusive; that the Government failed ■to prove essential elements of the crimes charged against him, that there was a variance in one of the charges against him, that the government “released false discovery” that hampered his ability to defend himself, and that he was prejudiced by the “unfair charging practice of the government.” Davidson Br. 24, 26. Prisque, like Davidson, argues that the verdicts against him were mutually exclusive. He also claims that the Government engaged in a pattern of prosecutorial misconduct against him, that the evidence was insufficient to convict him, and that the District Court erred in imposing his sentence. Finally, Maury challenges the sufficiency of the evidence against him. He also argues that his false statement conviction stemming from the December 1999 oil spill (Count 3) should be dismissed because the question posed to him was too ambiguous to support the charge, that there was a variance between the indictment and the evidence against him on that same charge, and that the District Court erred in allowing prejudicial testimony against him. II. Discovery Issues The Defendants raise many challenges to the degree of criminal discovery they were afforded throughout the proceedings in this case. Among the many arguments they raise, the Defendants argue that the District Court erred in its interpretation of Fed.R.Crim.P. 16(a), as it applies to organizational or, in this case, corporate defendants. We find the issue concerning the question of the extent of a corporate defendant’s right to discovery under Rule 16(a)(1)(C) to be the most deserving of attention and 'further discussion, and we therefore address it herein. Because we find that the discovery the Defendants received was adequate and in keeping with the standards of Fed,R.Crim.P. 16, we discern no error in the District Court’s handling of discovery in this case. A. Pre-Trial Discovery in a Criminal Case The Defendants’ arguments raised issues involving several overlapping aspects of pre-trial criminal discovery. We begin with a brief overview of a criminal defendant’s right to discovery of the evidence that the government intends to use against him at trial. In a criminal trial, the government is subject to three sets of disclosure obligations: those imposed under the Jencks Act, 18 U.S.C. § 3500(b), those imposed by Fed.R.Crim.P. 16 (“Rule 16”), a,nd those imposed by the Supreme Court’s holding in Brady v. Maryland, 373 U.S. 83, 83 S.Ct. 1194, 10 L.Ed.2d 215 (1963). 1. Jencks Material Pursuant to the Jencks Act, implemented by Federal Rule of Criminal Procedure 26.2, any time that a government witness testifies on direct examination, the defendant is entitled to a copy of “any statement ... of the witness in the possession of the United States which relates to the subject 'matter as to which the witness has testified.” 18 U.S.C. § 3500(b)(2). Provided the government contests the relevance of any portion of the statement, it must submit the entire statement to the court for in camera review. Id. § 3500(c). A “statement” is defined as (1)any written statement made and signed or adopted by the witness; (2) a “stenographic, mechanical, electrical, or other recording, or a transcription thereof’ that recites “substantially verbatim”, and was made contemporaneously with, the witness’s statement; or (3) a recording or transcript of grand jury testimony. Id. § 3500(e). The purpose of Jencks disclosure is to provide the defendant with an opportunity to review the witness’s statements for any possible inconsistencies that he might use to impeach the witness. United States v. Rosa, 891 F.2d 1074, 1076-77 (3d Cir.1989). Importantly, in light of this purpose, the government has no obligation to produce Jencks material until the witness has testified. 18 U.S.C. § 3500(a). This limitation does not apply to testimony by the defendant himself. Id.; see also Fed.R.Crim.P. 16. 2. Fed. R. Crim. P. 16 The bulk of the government’s pre-trial disclosure obligations stem from Rule 16, which requires that the government, “[ujpon a defendant’s request,” allow the defendant access to certain categories of information that the government has collected over the course of its investigation. With respect to an individual defendant, the government must disclose (1) “[A]ny relevant oral statement made by the defendant, before or after arrest, in response to interrogation by a person the defendant knew was a government agent if the government intends to use the statement at trial.” Fed.R.Crim.P. 16(a)(1)(A). (2) Any relevant “written or recorded statement by the defendant” if the statement is in the government’s possession or control, and the government knows of the statement. Id. 16(a)(l)(B)(i). (3) Any written record containing the substance of a defendant’s oral statements provided the statement is made in response to interrogation by a person the defendant knew to be a government agent. Id. 16(a)(l)(B)(ii). (4) Any recordings of the defendant’s grand jury testimony, if related to the offense. Id. 16(a)(l)(B)(iii). Organizational or corporate defendants are also entitled to pre-trial discovery. Fed.R.Crim.P. 16(a)(1)(C). However, in this context, the meaning of Rule 16 shifts. An organization has no self-knowledge of its own conduct, since it acts through its agents, and must be afforded an opportunity to learn what of its employees’ conduct is being used against it at trial. Thus, under Rule 16(a)(1)(C), an organizational defendant is entitled to any statement described in Rule 16(a)(1)(A) and (B), above, so long as the government contends that the person making the statement: (i) was legally able to bind the defendant regarding the subject of the statement because of that person’s position as the defendant’s director, officer, employee, or agent; or (ii) was personally involved in the alleged conduct constituting the offense and was legally able to bind the defendant regarding that conduct because of that pierson’s position as the defendant’s director, officer, employee, or agent. Fed.R.Crim.P. 16(a)(l)(C)(i), (ii). It is only by learning what statements can be attributed to it as an organization that a corporate defendant can defend itself at trial. Fed.R.Crim.P. 16(a)(1)(C) Advisory-Committee Notes to 1994 Amendments. Moreover, the government must allow any defendant to review any “books, papers, documents, data, photographs, tangible objects, buildings or places” that are material to the defense, provided that the government intends to use that evidence in its case-in-chief or that the item was obtained from the defendant. Fed.R.CrinkP. 16(a)(1)(E). These obligations are subject to a carve-out for attorney or agent work product “made ... in connection with investigating or prosecuting the case.” Fed.R.Crim.P. 16(a)(2). Rule 16 also makes clear that it does not authorize “discovery or inspection of statements made by prospective government witnesses except as provided” under the Jencks Act, 18 U.S.C. § 3500. Fed. R.Crim.P. 16(a)(2). 3. Brady and Giglio material Finally, independent of these obligations, under Brady v. Maryland, a prosecutor has an obligation to disclose “evidence favorable to an accused” individual so long as it is “material either to guilt or to punishment.” 373 U.S. 83, 87, 83 S.Ct. 1194, 10 L.Ed.2d 215 (1963). Evidence is “material” if there is a reasonable probability that, “had the evidence been disclosed to the defense, the result of the proceeding would have been different.” United States v. Friedman, 658 F.3d 342, 357-58 (3d Cir.2011) (quoting United States v. Bagley, 473 U.S. 667, 682, 105 S.Ct. 3375, 87 L.Ed.2d 481 (1985)). “The prosecution must also disclose evidence that goes to the credibility of crucial prosecution witnesses.” Buehl v. Vaughn, 166 F.3d 163, 181 (3d Cir.1999) (citing Giglio v. United States, 405 U.S. 150, 154, 92 S.Ct. 763, 31 L.Ed.2d 104 (1972)). Referred to as Giglio material, this evidence is a subset of Brady material insofar as it addresses situations in which certain evidence about a witness’s credibility or motivation to testify exists, and where “the reliability of a given witness may well be determinative of guilt or innocence.” Giglio, 405 U.S. at 154, 92 S.Ct. 763 (citing Napue v. Illinois, 360 U.S. 264, 79 S.Ct. 1173, 3 L.Ed.2d 1217 (1959)). B. Pre-Trial Discovery in this Case Fed.R.Crim.P. 16(d)(1) allows a court to, “for good cause, deny, restrict, or defer discovery or inspection, or grant other appropriate relief.” In this case, the District Court granted a protective order allowing delayed disclosure of certain employees’ statements that the government sought to use in its case against the Company — in other words, statements that the Court believed fell within the reach of Rule 16(a)(1)(C). In granting that request, it reviewed in camera the statements themselves, and the Government’s affidavits in support of their motion. It determined that delayed production was the only way to “protect the safety of prospective witnesses and the likelihood that they will appear and testify without intimidation or improper influence at trial.” (J.A. 652.) The Court also- determined that alternative, less drastic proposals, such as producing the materials with redactions of the employees’ names, or ordering disclosure of a list of the sought after statements and allowing the full documents to be produced later, would “undermin[e] the effect of the protective order to be issued.” (J.A. 652.) In the wake of the District Court’s initial decision granting the protective order, the Defendants filed several motions to compel discovery on a host of grounds. In October 2004, the Defendants also argued that, despite the Court’s protective order, they were immediately entitled to any and “all statements made by the ‘co-conspirators’ referenced in the Superseding Indictment, as the United States is clearly attempting to bind the [CJompany by the acts and/or statements of those co-conspirators,” as well as “all statements of employees whose alleged conduct binds Atlantic States.” (J.A. 695.) (citing Fed.R.Crim.P. 16(a)(1)(C) (the “Rule 16 motion”)). They argued that even if the employees’ identities were protected under the Court’s order, any and all statements by the employees should be turned over immediately. Importantly, these statements concerned not so much the scope of Rule 16(a)(1)(C), but whether the Defendants were entitled to anything under Rule 16(a)(1)(C) prior to 30 days before trial. See J.A. 695. The Defendants’ continuing demands for information concerned the timing of the Government’s disclosures, not the scope thereof. The Court reserved decision on the Rule 16 motion, pending further in camera review of the evidence, and noted that it would decide the Rule 16 motion in conjunction with the Defendants’ Motion for Reconsideration of the Protective Order. The Court intended to use that additional in camera review to determine whether the scope of the protective order could be narrowed. Following additional arguments and the Court’s in camera review, on February 17, 2005, the Court denied the motion to reconsider the protective order. On August 12, 2005, consistent with the Court’s protective order, the Government produced the previously withheld Rule 16(a)(1)(C) materials to the Defendants. In all, the production consisted of documents for 24 witnesses. Portions of these documents were heavily redacted, in keeping with the Government’s understanding of the scope of Rule 16(a)(1)(C). For individuals who could bind the Company by virtue of their position alone, the Government produced all oral statements that it intended to use at trial, and all written statements discussing issues on which the employee had the authority to bind the Company. See Rule 16(a)(1)(C)®. For all employees who were capable of binding the Company by virtue of their participation in the charged events, ie. employees who had participated directly in the charged conduct, the Government produced all oral and written statements discussing that specific conduct. See Rule 16(a)(l)(C)(n). All other statements from these individuals, such as statements unrelated to t