Full opinion text
JOHN R. GIBSON, Circuit Judge. This is the appeal of five defendants convicted of multiple drug and gun crimes in connection with their operation of a drug trafficking business on the Pine Ridge Oglala Sioux Reservation in South Dakota. Geraldine Blue Bird argues that the district court erred in failing to suppress evidence discovered as a result of Fourth Amendment violations; in allowing the government to strike one venire-member and in excusing another venire-member for cause; in entering a judgment of conviction for gun and drug offenses without sufficient evidence; in allowing hearsay statements and opinion testimony; in admitting evidence seized pursuant to a warrant that the government did not produce in discovery; and in determining an appropriate sentence. Colin Spotted Elk argues that his Sixth Amendment confrontation rights were violated when the district court admitted testimony that Blue Bird had implicated him in a scheme to cover up the conspiracy. Spotted Elk also contends that his conviction on Count VI must be reversed because the jury was wrongly instructed that taking a gun in exchange for drugs would satisfy the “use” element of 18 U.S.C. § 924(c); the government confesses error on this point in light of Watson v. United States, — U.S. -, 128 S.Ct. 579, 169 L.Ed.2d 472 (2007), which was decided while this appeal was pending. Marvella Richards contends that the prosecutor improperly used a peremptory strike to eliminate a venire-member on account of her race. She also contends that the district court erred in assessing a two-level enhancement in her Sentencing Guidelines offense level for use of a minor to commit a crime and that the district court’s sentence was unreasonable under 18 U.S.C. § 3558(a). Rusty Richards contends that the district court should have severed his case from the others and that he should have been sentenced as a minimal participant. Flint Thomas Red Feather contends that the district court committed numerous errors in sentencing him. We reverse Spotted Elk’s gun conviction under § 924(c), and remand for resentenc-ing on the remaining counts of conviction; we remand Red Feather’s sentence for findings regarding the scope of his joint criminal undertaking and the foreseeability to him of his co-conspirators’ drug transactions; and we affirm in all other respects. I. The Evidence at Trial. The evidence in this eleven-day trial showed that Geraldine Blue Bird headed up a cocaine sales organization that supplied drug users on the Pine Ridge Oglala Sioux Reservation. Blue Bird’s organization consisted primarily of her extended family and intimate friends, many of whom lived together in a neighborhood in Pine Ridge known as the Igloos, where they retailed cocaine they picked up in Denver. The charges to be proved were contained in an eight-count indictment, which alleged a conspiracy to distribute cocaine, a conspiracy to distribute marijuana, various discrete acts of possession of cocaine with intent to distribute, and carrying or using firearms during and in relation to drug trafficking violations. The evidence at trial was principally of two kinds: co-conspirators testifying under various arrangements with the government and police officers describing the investigations that led to the arrest of Blue Bird and the other defendants. The co-conspirator testimony came from Blue Bird’s family and friends who had taken part in the drug operation. In rough outline, their testimony showed that the family drug business began with Blue Bird’s son Colin Spotted Elk, who began selling marijuana from what was called the “blue house” in the Igloos in the 1990s. Eventually, Blue Bird gained control of what was once her son’s business, and by the time of the 2002-2005 period at issue in the indictment, she made the important decisions and controlled the money. Spotted Elk was eventually relegated to the third tier of control, while a succession of three women, Dawnee Frogg, Janine Cot-tier, and Jody Richards, occupied the position of second in command. Spotted Elk supervised the retail sellers, who called themselves the “Igs” and many of whom had a distinctive tattoo. Rusty Richards and Flint Thomas Red Feather were retail-level sellers, and Red Feather also helped with packaging cocaine, holding cocaine, and counting money. Marvella Richards, Blue Bird’s niece, would hold the cocaine and “reup” the retail-level sellers. “Reupping,” in their patois, meant turning in the proceeds from one consignment of cocaine, usually an “eight pack” of eight half-gram packets, and receiving a new consignment. The organization charged $50 per half gram of cocaine, but would accept some barter. In particular, Blue Bird would accept electronic benefit (or “EBT”) cards which were issued by the government as food assistance, but Blue Bird would discount the cash value of the cards by half or more. The organization also accepted guns in payment for drugs on occasion. Spotted Elk, in particular, was interested in guns, and he authorized Thomas Spotted Bear to accept a gun in exchange for a half gram of cocaine. By the time the business was in full swing in 2005, Blue Bird herself or some group of her associates would travel to Denver about once a month to buy a kilogram of cocaine. Blue Bird’s business was apparently something of an open secret in Pine Ridge, since the stream of customers was so great as to cause traffic jams, particularly on the first of the month, which was pay day on the reservation. In June 2005, Blue Bird moved from the reservation to Rapid City, South Dakota, but many of her family and friends stayed on in her blue trailer and in the blue house in the Igloos. The trial evidence detailed how police surveilled the houses she owned in the Igloos, as well as the house she had moved into at 629 Indiana in Rapid City, South Dakota, and gradually amassed evidence of the cocaine operation going on at those places. First, early in the morning of March 20, 2005, Oglala Sioux Tribal Police Officer David Whary was dispatched to Blue Bird’s blue trailer in the Igloos on a call that someone was being assaulted there. Justin Hawk Wing met the officers outside the trailer and told officers they could go inside, which they did. Once inside, Whary moved through the house in a protective sweep; in plain view he saw pieces of aluminum foil with burn marks, which suggested to him that someone had been smoking cocaine; cut up squares of magazine paper; a pipe; plastic baggies with marijuana in them; and EBT cards in many different names, including names of people who were not in or apparently living in the trailer. Second, in September 2005, Agents Daniel Cooper of the FBI and Derrick Hill of the ATF conducted a “trash pull,” picking up the contents of trash containers set outside the curtilage at the Rapid City house. In the trash, they found burned aluminum foil and spoons, which are commonly used to smoke or process cocaine, as well as pieces of magazine paper cut up into squares and plastic bags knotted up to allow use of one corner of the bag. They also found notes listing names, amounts of money and quantities, which Agent Cooper testified appeared to him to be a ledger for tracking who had what amounts of drugs. Additionally, the trash yielded a bindle of cocaine weighing .34 ounces. Third, on September 17, 2005, Officer Whary arrested Blue Bird at Dale Richards’ house in Pine Ridge on outstanding warrants (apparently on matters unrelated to drugs). As he took her into the Tribal jail, she asked him how much her bond would be and told him that she had $5,000 in cash in her pocket. Later, during her booking, she did in fact produce almost that amount of cash. While she was being booked, Blue Bird was seen “aggressively” pushing something down in her pants. A female officer, Pamela Janis, took Blue Bird into a private room in order for her to change into jail clothes. Officer Janis noticed Blue Bird moving a cart with her leg. When Blue Bird had changed clothes, Janis looked under the cart and found a package wrapped in duct tape, which contained two plastic baggies, each containing eight bindles of what was later determined to be cocaine. Janis picked up the package off the floor and looked at Blue Bird, who said, “Can I talk to you? I need to talk to you,” and, “This is all about my son.” Finally, police closed in on Blue Bird’s organization on December 21, 2005, when the manager of the Ramada Inn in Rapid City, South Dakota, smelled what he thought was burning marijuana in the hall of the motel and called the police. The rooms from which the smell seemed to be emanating, Rooms 131 and 133, had been rented that day by Norton Richards. Rapid City Police Officer Ron Terviel responded to the call. He and the hotel manager knocked at the door of Room 131. Terviel saw light fluctuating through the peephole, but no one answered, so the hotel manager moved on to Room 133 and knocked several times. Blue Bird answered the door and consented to allow Terviel to enter the room. He smelled marijuana and saw a baggie containing four hand-rolled cigarettes on the credenza. Terviel asked Blue Bird’s name and ran a warrant check on her, and she volunteered that she had a warrant for driving without proof of insurance. Terviel prepared to arrest Blue Bird, and he asked if she had anything that could stick him if he searched her. She answered that she had cocaine in her pockets, but that it belonged to her son Clarence Behan and she was only holding it for him. In fact, Terviel found six bindles of cocaine in one of Blue Bird’s pockets and five bindles in the other. Terviel asked Blue Bird about Norton Richards, who had rented the room. Blue Bird answered that Norton was in the next room, and Terviel asked the other occupant of the room, Jody Richards, if she would knock on the interior door so that he could speak with Norton. Jody knocked and Norton answered the door and walked into Room 133. Terviel walked out into the main hall to speak to the hotel manager; the door to Room 131 was open and through the open door, Ter-viel saw a bindle on the floor, together with a rolled up dollar bill, which, based on his training, he knew was something people use to snort drugs. Terviel called for back up and assembled all four occupants of Rooms 131 and 133 — Blue Bird, Jody Richards, Wenona Richards and Norton Richards — in Room 133 to wait for a detective to arrive. When Jody Richards complained that she was cold, Terviel saw a jacket on the bed. He asked Blue Bird if it was hers, and she said yes. He got her permission to give the coat to Jody, but when he picked it up, underneath the coat he found two Tupperware containers covered in duct tape. Detective Tony Harrison, who had arrived, picked up the containers and saw white powder inside. Harrison immediately sealed the scene to apply for a search warrant. After the warrant arrived, police seized the Tupperware containers, which contained 56.2 grams of cocaine. The search of the room also produced a backpack that contained ammunition, handguns, $16,500 in cash wrapped in plastic and duct tape, and paper squares of the type used to make bindles. The police also found pieces of tinfoil of the type used for smoking cocaine and plastic packaging with a layer of grease around it, which is a wrapping method drug dealers use to avoid detection by drug-sniffing dogs. Blue Bird’s purse contained about $1,000 in cash, wrapped in plastic wrap. Police also found a first-aid kit box that contained a digital scale, partially folded bindles, and a small plastic bag with cocaine in it. The next day, Detective Harrison saw a green van parked in the Ramada Inn parking lot; he looked in the window and saw gun barrels sticking out of a trash bag. The van was found to contain four shotguns and six long rifles. It turned out that Blue Bird and Jody, Wenona, and Norton Richards had traveled to the Ramada Inn in that van. After Blue Bird and the others at the Ramada Inn were arrested on December 21, 2005, federal officials executed a search warrant at the blue trailer in the Igloos, which Blue Bird still owned, but which she had vacated the previous June. Police seized drug paraphernalia and a semi-automatic assault rifle from the trailer. After Blue Bird’s arrest, she was evicted from 629 Indiana. Her landlord consented to a search of the vacated premises, which turned up a green spiral notebook with notes consistent with a drug ledger and an EBT card in the name of Holly Wilson. The jury found each defendant guilty on each count of the indictment. II. Suppression Issues. Geraldine Blue Bird contends that various pieces of evidence should have been suppressed because they were discovered in violation of the Fourth Amendment or, in the case of statements, resulted from such violations. She challenges police actions in four different episodes: (1) the entry into her house trailer during a party on March 20, 2005; (2) the seizure of her trash from the alley near her house at 629 Indiana in Rapid City in September 2005; (3) the entry into the house of Dale Richards on September 17, 2005 in order to arrest Blue Bird; and (4) the encounter at the Ramada Inn on December 21, 2005, including the entry into Room 131, the search of the Tupperware containers, and the search the next day of the green van parked outside the Ramada Inn. Blue Bird made three motions to suppress, and indeed she prevailed in several of her arguments. In reviewing the district court’s rulings on suppression motions, we review for clear error the questions of historical fact, such as who said what. See Ornelas v. United States, 517 U.S. 690, 699, 116 S.Ct. 1657, 134 L.Ed.2d 911 (1996); United States v. Elam, 441 F.3d 601, 603 (8th Cir.2006). The question of whether a person expressed consent to a search is a question of fact, as is the question of whether such consent was voluntary. United States v. Jones, 254 F.3d 692, 695-96 (8th Cir.2001). The ultimate question of whether a search violated the Fourth Amendment is a mixed question of fact and law that we review de novo. See Ornelas, 517 U.S. at 696-99, 116 S.Ct. 1657; United States v. Wheat, 278 F.3d 722, 725 (8th Cir.2001). A. March 20, 2005 Entry into Blue Bird’s House Trailer. The March 20, 2005 entry into Blue Bird’s house trailer was precipitated by a 911 call to police. Oglala Sioux Tribal Police Officer David Whary testified at the suppression hearing that he responded to the call, in which someone told the dispatcher that “a female [was] getting assaulted” at Geraldine Blue Bird’s double-wide trailer. When he arrived there, other officers were already there, waiting for backup. They told him that Justin Hawk Wing told them that “Kim Pacer was flashing a knife ... looking for her boyfriend and was threatening subjects in the house with the knife.” They said that Hawk Wing had invited the officers to go into the trailer. Whary walked in the front door and began a protective sweep of the trailer because the officers had heard rumors that the people at the trailer wanted to have a shoot-out with the police. The door to the east bedroom was locked, but the people inside the bedroom came out; when they did, Whary saw a “gray package bundle” or “duct tape package” sitting inside an open cabinet. In the bathroom, he saw burnt pieces of aluminum foil, a burnt piece of glass pipe, and plastic bags ripped open. There was a safe in the living room, a gun and ammunition in plain view, and numerous EBT or electronic food stamp cards. The police seized the guns, ammunition, foil, a crack pipe, and EBT cards, all of which were exposed to their plain view once they entered the trailer. Blue Bird moved to suppress the evidence on the ground that the police violated the Fourth Amendment when they entered her residence without a warrant. The district court found that the police acted reasonably in response to exigent circumstances: Whary and his fellow officers reasonably believed that an emergency situation, namely an assault, was occurring at the Blue Bird home. Under the “emergency exception” to the warrant requirement, their entry into the Blue Bird home was justified. The officers did not act outside their justification for entrance in moving through the home in an attempt to find the reported assault victim. Generally, the Fourth Amendment requires the police to obtain a warrant before entering a home. Payton v. New York, 445 U.S. 573, 590, 100 S.Ct. 1371, 63 L.Ed.2d 639 (1980). Where, as here, the police have entered a defendant’s house without a warrant, the burden is on the prosecution to prove that the police acted pursuant to a valid exception to the warrant requirement. United States v. Weston, 443 F.3d 661, 667 (8th Cir.), cert. denied, 549 U.S. 956, 127 S.Ct. 417, — L.Ed.2d - (2006). One exception is that police are allowed to enter a home without waiting for a warrant in the face of certain exigent circumstances, such as when they reasonably believe that a person within is in need of immediate aid. Brigham City v. Stuart, 547 U.S. 398, 403, 126 S.Ct. 1943, 164 L.Ed.2d 650 (2006); Mincey v. Arizona, 437 U.S. 385, 392, 98 S.Ct. 2408, 57 L.Ed.2d 290 (1978). When police have lawfully entered the house in response to exigent circumstances, they may conduct a protective sweep, or cursory inspection of places where a person might be, if the facts would justify a reasonable officer in believing that there might be someone dangerous in the house. United States v. Williams, 431 F.3d 1115, 1118 (8th Cir.2005); United States v. Pruneda, 518 F.3d 597, 603 (8th Cir.2008). Once lawfully inside the home, police may seize obviously incriminating items that are in plain view and that can be reached from somewhere the officer has a right to be. United States v. Chipps, 410 F.3d 438, 442-43 (8th Cir.2005); Williams, 431 F.3d at 1118; see United States v. Banks, 514 F.3d 769, 773 (8th Cir.) (plain view doctrine generally), cert. denied, — U.S. -, 128 S.Ct. 2919, 171 L.Ed.2d 853 (2008). Blue Bird contends that there were “no facts supporting the report that any person had been assaulted or injured.” To the contrary, Justin Hawk Wing told the officers on the spot that Kim Pacer was “flashing a knife” and that she “was looking for her boyfriend and was threatening subjects in the house with the knife.” Police in fact found Kim Pacer in the trailer and arrested her. This was adequate evidence. to justify the police entry of the trailer in order to prevent violence and restore order. See Stuart, 547 U.S. at 406, 126 S.Ct. 1943, 164 L.Ed.2d 650 (“The role of a peace officer includes preventing violence and restoring order, not simply rendering first aid to casualties; an officer is not like a boxing (or hockey) referee, poised to stop a bout only if it becomes too one-sided.”). B. Entry into Dale Richards’ Home on September 17, 2005. Blue Bird also contends there was a Fourth Amendment violation when police entered the home of Dale Richards on September 17, 2005 to arrest her; accordingly, she contends that the court should have suppressed the cocaine that was found on the dressing room floor of the police station where she changed clothes and statements she made while in custody. Blue Bird argues that the district court erred in holding that Justin Hawk Wing had authority to consent to the police’s entry of Richards’ trailer, where they found and arrested her. Here, police had an arrest warrant, but they executed the warrant by entering a third person’s home. In the absence of exigent circumstances or other exception to the warrant requirement, police seeking to execute an arrest warrant for one person at someone else’s home need a search warrant to enter the third person’s house. Steagald v. United States, 451 U.S. 204, 211-16, 101 S.Ct. 1642, 68 L.Ed.2d 38 (1981). The police may enter and search a person’s house with the voluntarily given consent of that person or with the consent of a third party who shares “common authority over the premises or effects” to be searched, United States v. Matlock, 415 U.S. 164, 170, 94 S.Ct. 988, 39 L.Ed.2d 242 (1974), provided that the person does not object, see Georgia v. Randolph, 547 U.S. 103, 122-23, 126 S.Ct. 1515, 164 L.Ed.2d 208 (2006); United States v. Hudspeth, 518 F.3d 954, 960-61 (8th Cir.2008) (en banc) (holding that defendant must be physically present to overrule third party’s consent). Whether the third party expresses consent is a question of fact. See Iron Wing v. United States, 34 F.3d 662, 665 (8th Cir.1994); see also United States v. Jones, 254 F.3d 692, 695 (8th Cir.2001) (“The determination of whether Jones expressed consent is a question of fact, which we review for clear error.”). Whether the consenter had common authority over the premises is also a question of fact and is determined by the existence of “mutual use, joint access, and control.” United States v. James, 353 F.3d 606, 613 (8th Cir.2003). However, whether the reliance by police on indicia of common authority was reasonable is a question of law that we review de novo. Id. at 615; Weston, 443 F.3d at 668. Officer Whary arrived at the Dale Richards residence on September 17, 2005 with an arrest warrant for Blue Bird, having been told by an informant’s telephone call that she was at Richards’ trailer. When Whary arrived, Justin Hawk Wing was standing in front of Richards’ trailer. Whary testified that he had called at Dale Richards’ trailer “dozens and dozens of times” and that he had encountered Hawk Wing there many times, including times when Hawk Wing was sleeping there. Whary testified that Hawk Wing appeared to be living at the trailer. Whary asked Hawk Wing, “Is Geraldine home?” Hawk Wing replied, “I don’t know. Go look,” and he pointed toward the trailer. Interpreting the gesture as an invitation, Whary walked up to the door of the trailer, knocked, and went inside. He encountered Richards, who did not object to his entry. Whary walked to a bedroom, where he saw Blue Bird sitting on a mattress on the floor, and he arrested her. The district court found, Whary’s determination that Hawk Wing had common authority over Richards’ home, based upon his belief that Hawk Wing lived in the home, was reasonable. Therefore Hawk Wing’s consent to enter the trailer was effective. Further, immediately after Whary entered Richards’ home, he encountered Richards who gave no indication that he did not consent to his presence. Blue Bird argues, “There were no facts establishing that Justin Hawk Wing had any authority whatsoever to authorize entrance into the Richards residence.” Whary testified that he had seen Justin Hawk Wing at the Richards trader many times, including times when Hawk Wing was asleep there, and that Hawk Wing appeared to be living there. When asked if Blue Bird was in the trailer, Hawk Wing invited Whary to go inside and see for himself whether Blue Bird was in the trailer, thus exercising a prerogative of admitting strangers into the house, which would be proper only for an inmate of the house. This is adequate evidence on which a reasonable officer could base a conclusion that Hawk Wing had authority to consent to entry into the trailer. See Weston, 443 F.3d at 668; United States v. Janis, 387 F.3d 682, 687 (8th Cir.2004). C. Trash Pull at 629 Indiana. Blue Bird contends that the district court should have suppressed evidence the police retrieved from trash cans left at the curb of Blue Bird’s house at 629 Indiana in Rapid City, South Dakota in September 2005. Blue Bird did not move to suppress this evidence before trial; she argues she did not know before trial that the trash had been seized, but that when she found out, she made a trial objection, which was overruled. The government contends that a suppression motion must be made before trial, see Fed.R.Crim.P. 12(b)(3)(C) (including suppression motion as one that “must be made before trial”), and that this issue is either nonreviewable or, at most, reviewable as plain error. See United States v. Frazier, 280 F.3d 835, 845 (8th Cir.2002). It is not necessary to belabor the applicable standard of review, or indeed to decide whether the issue is reviewable, since the district court did not err under any standard in admitting the evidence. FBI Agent Dan Cooper testified that he removed two trash containers that were “set out” in the alley outside the fence at 629 Indiana. Inside the trash containers, he found burnt foil, baggies, paper with notations that could be drug transaction ledgers, a bindle containing .34 grams of cocaine, and miscellaneous other items that Cooper connected with the drug trade. Police may search trash left outside the curtilage of the house to be picked up by garbage collectors, because the owners of the trash have abandoned it. Calif ornia, v. Greenwood, 486 U.S. 35, 40-43, 108 S.Ct. 1625, 100 L.Ed.2d 30 (1988); United States v. Trice, 864 F.2d 1421, 1423-24 (8th Cir.1988) (trash in trash cans at the curb for pickup). Just so, here. The garbage was in the alley, outside the fence. Blue Bird could not prevail on this argument no matter what standard of review we applied. D. Entry and Searches at Ramada Inn. Blue Bird contends that her Fourth Amendment rights were violated in various respects by the actions of police on December 21, 2005, when they entered her motel room at the Ramada Inn in Rapid City, and on the next day, when they looked through the windows of a van in the parking lot there. On December 21, Blue Bird and Jody Richards were occupying Room 133 at the Ramada, and Norton and Wenona Richards were in Room 131. Norton Richards had rented both rooms. Josh Uhre, the motel manager, smelled something like marijuana or “toilers” (cocaine and baking soda burned in foil) coming from the vicinity of those rooms. He also saw a man in the hall wearing a shirt with a picture of a marijuana leaf. Someone from the motel called the police, and when Officer Ron Terviel arrived, Uhre went down with Ter-viel to the rooms. First, they knocked on the door of Room 131, and Uhre said, “Front desk,” but no one answered. Ter-viel peeked in the peephole and saw some movement. They moved over to Room 133 and knocked and announced “Front desk,” and Uhre said through the door that someone was smoking marijuana. Geraldine Blue Bird opened the door. Terviel asked if it was her room, to which she said yes, and then he asked if he could come in, to which she also answered yes. Terviel noticed the smell of marijuana and he saw a bag of marijuana cigarettes in plain view on the credenza or dresser. He asked Blue Bird her name, and when she told him, he found she had an outstanding warrant for driving without insurance. He took her into custody. He asked her where Norton Richards was, and Blue Bird said he was in the other room. Jody Richards knocked on the door by which Rooms 131 and 133 communicated; Norton Richards opened the door and came in to Room 133, while Jody crossed over into Room 131. Officer Terviel asked Blue Bird if there was anything he should know about before searching her, and she said she would like to speak to him and that she had cocaine in her pockets. Terviel searched her pockets and found a baggie full of bindles. Blue Bird volunteered that the bindles belonged to her son, but Ter-viel warned her not to speak before receiving her Miranda warnings. Terviel went into the hall to speak to Uhre, and while he was out there, Jody Richards opened the door and stuck out her head. Through the open door, Terviel could see another bindle and a rolled-up dollar bill, which he said is associated with cocaine use. Terviel called for backup. As everyone was sitting in the room waiting for more officers to arrive, the rooms became cold because the officers had opened the windows (presumably to fumigate). When Jody Richards complained of the cold, Terviel saw a coat on the bed and asked Blue Bird if it was her coat and if he could give it to Jody. With Blue Bird’s consent, he picked up the coat and thereby revealed two Tupperware containers sitting under the coat, sealed with duct tape. Another officer, Detective Harrison, picked up a Tupperware container and Terviel could see that there was something white and powdery in it. At that point, Detective Harrison said to stop everything, that they would get a search warrant for the room. Armed with the search warrant, police found weapons, cash, drug paraphernalia, and controlled substances. The next morning, Detective Harrison returned to the Ramada Inn with a set of keys that had been seized the previous day. He looked in the window of a van parked in the Ramada Inn parking lot and saw the barrels of two guns sticking out from a trash bag. He used the keys to open the van and found four shotguns and six long rifles. Blue Bird moved to suppress the items found in the motel rooms, as well as the statements she made to Officer Terviel. The district court denied the suppression motion, finding that Blue Bird voluntarily consented to Terviel’s entrance into her room, that the marijuana cigarettes were in plain view in the room, and that Norton Richards voluntarily consented to Terviel’s entry into his room, where more incriminating evidence was readily apparent. Further, the district court held that the statements by Blue Bird to Terviel were not the product of interrogation, but instead were volunteered by Blue Bird. She did not include the evidence of the guns in the van in her pre-trial suppression motion, though she objected to the evidence at trial, and the district court overruled her motion on the ground that it was not her van and she had no standing to object. On appeal, Blue Bird attacks Terviel’s entry into Blue Bird’s room, arguing that Terviel lacked probable cause to knock on the door of Room 133, that by looking in the peephole in the door of Room 131, he committed an unreasonable search, and that Blue Bird did not voluntarily consent to his entry of her room. First, it does not violate the Fourth Amendment merely to knock on a door without probable cause. United States v. Cruz-Mendez, 467 F.3d 1260, 1264 (10th Cir.2006) (“As commonly understood, a ‘knock and talk’ is a consensual encounter and therefore does not contravene the Fourth Amendment, even absent reasonable suspicion.”), cert. denied, 549 U.S. 1151, 127 S.Ct. 1027, 166 L.Ed.2d 773 (2007); see United States v. Weston, 443 F.3d 661, 667 (8th Cir.2006) (police did not violate Fourth Amendment when they entered defendant’s curtilage for legitimate purpose of seeking voluntary conversation and consent to search). Officer Terviel and Uhre stood in a public hallway and knocked on the door. “[N]o Fourth Amendment search occurs when police officers who enter private property restrict their movements to those areas generally made accessible to visitors — such as driveways, walkways, or similar passageways.” United States v. Reed, 733 F.2d 492, 501 (8th Cir.1984). While a police attempt to “knock and talk” can become coercive if the police assert their authority, refuse to leave, or otherwise make the people inside feel they cannot refuse to open up, United States v. Poe, 462 F.3d 997, 1000 (8th Cir.2006); United States v. Conner, 127 F.3d 663, 666 (8th Cir.1997), in this case there are no facts that would show that Blue Bird had reason to feel she had to open up. The encounter happened in midday, Terviel did not command her to open the door, nor was there any suggestion that his knocking was unusually persistent. See United States v. Crapser, 472 F.3d 1141, 1146-47 (9th Cir.2007). The district court found that Blue Bird opened the door of the motel room of her own accord, and that finding is not clearly erroneous. Second, whether or not looking into a peephole is a search, Officer Terviel did not see anything incriminating when he looked in, so there is no causal connection between the peeping and the later discovery of evidence that Blue Bird would like suppressed. A constitutional violation does not call for suppression of physical evidence or statements when the violation did not canse the discovery of the evidence or the utterance of the statements. United States v. Olivera-Mendez, 484 F.3d 505, 511 (8th Cir.2007). Third, the district court’s finding, under the guidance of United States v. Chaidez, 906 F.2d 377, 380-81 (8th Cir.1990), of voluntary consent to entry of Room 133 was not clearly erroneous. The district court found that “Blue Bird answered the door to the room on her own accord,” “she was not in custody when she gave Terviel permission to enter the room,” “Terviel never raised his voice or threatened Blue Bird,” and “Blue Bird is a mature adult who was familiar with the workings of the criminal justice system.” In arguing that her consent was not voluntary, Blue Bird relies on various of her personal characteristics (physical impairments resulting from obesity, cocaine intoxication, etc.), of which she adduced no evidence at the suppression hearing and which are not mentioned in her motion to suppress. We cannot conclude the district court erred in not finding facts based on evidence not presented to it, nor would we conclude that the facts Blue Bird now urges would have rendered the district court’s findings clearly erroneous even if they had been developed below. Next, Blue Bird contends that the district court erred in refusing to suppress the contents of the Tupperware containers because the police entry into the room was illegal, an argument we have already rejected, and because the police opened the containers without a warrant. Blue Bird did not argue in her suppression motion that the containers were opened without a warrant, and the only testimony before the district court on the suppression motion was that the officers stopped once they discovered the Tupperware containers and proceeded to get a search warrant before searching the motel rooms. Later, at trial, Jody Richards testified that Officer Harrison opened up the container on the spot, which implies that he did not wait for the warrant. Blue Bird does not contend that she asked the district court to suppress the contents of the containers based on Jody Richards’ trial testimony. Federal Rule of Criminal Procedure 12(b)(3)(C) and (e) provides that motions to suppress evidence must be raised before trial or are waived, and the waiver provision “applies not only to the failure to make a pretrial motion, but also to the failure to include a particular argument in the motion.” United States v. Barajas-Chavez, 358 F.3d 1263, 1266-67 (10th Cir. 2004) (internal quotation marks omitted); see generally 1A Charles Alan Wright & Andrew D. Leipold, Federal Practice & Procedure Criminal § 193 at 424-26 (4th ed.2008). The district court could hardly be faulted for failing to grant the suppression motion on the basis of facts not presented to it, and Blue Bird did not renew her motion in light of Jody Richards’ testimony. Even if Blue Bird had presented Jody Richards’ testimony at the motion to suppress, Richards’ testimony was contradicted by the trial testimony of Officer Harrison, who said the containers were not opened until the next day at the evidence facility. Presumably, the government would have countered Richards’ story with its contrary version of the facts. Therefore, even if we were to review this point for plain error, we would have to conclude that any error was not plain. Blue Bird also contended at oral argument that even after the search warrant was obtained, it did not authorize the search of the Tupperware containers because it did not mention them. Our review of the warrant (not supplied to us by counsel) indicates that this argument is unfounded, since the warrant specifically mentions “containers ... used in packaging or delivering contraband substances.” Finally, Blue Bird contends that the district court should have suppressed the guns that Detective Harrison discovered by looking through the windows of the green van belonging to Darrell or Melinda Spotted Elk, which was parked outside the Ramada Inn. Blue Bird did not move before trial to suppress this evidence, but instead objected when Harrison testified at trial about seeing the guns. After Blue Bird’s counsel objected, he then informed the court that the van was not Blue Bird’s. The district court said that it would appear that Blue Bird did not have standing to object to the search, unless counsel was “aware of something that would give her standing.” To this, counsel replied, “It’s not our vehicle.” On appeal, Blue Bird contends that she has standing because she had been a passenger in the van on December 21, the day before Detective Harrison saw the guns. The general rule is that “a person has no reasonable expectation of privacy in an automobile belonging to another.” United States v. Green, 275 F.3d 694, 699 (8th Cir.2001). Blue Bird cites Brendlin v. California, 551 U.S. 249, 127 S.Ct. 2400, 168 L.Ed.2d 132 (2007), in which a passenger who was in the car at the time of a traffic stop was deemed “seized” and thus had standing to challenge the stop. Blue Bird does not cite any authority for the proposition that a person who was a passenger in the past retains standing to challenge future searches of someone else’s car. Even assuming this argument for suppression is reviewable despite Blue Bird’s waiver under Rule 12(e), the district court did not plainly err in admitting evidence about the guns. III. Severance Motion. Rusty Richards argues that the district court erred in denying his motion to sever his case from those of the other defendants. Rusty Richards was indicted on Count I, conspiracy to possess with intent to distribute, and to distribute, five kilograms or more of cocaine. Fifteen other defendants were indicted in Count I, and there were seven additional counts that did not name Rusty Richards. Ultimately, five defendants proceeded to trial. Before trial, Rusty Richards moved to sever his case from that of Geraldine Blue Bird and Colin Spotted Elk, arguing that the extensive evidence against those two created a danger that Rusty Richards would be found guilty by association. The district court held that the indictment properly joined the various counts, which all involved illicit possession and distribution of controlled substances over a relatively short period of time and which were all related to the conspiracy alleged in Count I. Once join-der was shown to be proper, the district court reasoned that the burden fell on Rusty Richards to demonstrate that a joint trial would result in real prejudice to him. The district court held that Rusty Richards had not come forward with any reason to believe that a joint trial would prejudice him. The district court instructed the jury that each defendant was entitled to have his or her case decided solely on the evidence that applied to him or her and that some of the evidence in the case applied only to some defendants and could not be considered against others. We review for abuse of discretion the district court’s denial of a severance motion. United States v. Frazier, 280 F.3d 835, 844 (8th Cir.2002). The burden is on the defendant to show that he was clearly prejudiced by the joint trial, and “it will be the rare case, if ever, where a district court should sever the trial of alleged coconspirators.” Id. Severance is appropriate “only if there is a serious risk that a joint trial would compromise a specific trial right of one of the defendants, or prevent the jury from making a reliable judgment about guilt or innocence.” Zafiro v. United States, 506 U.S. 534, 539, 113 S.Ct. 933, 122 L.Ed.2d 317 (1993). Rusty Richards argues that his involvement in the conspiracy was less extensive and less culpable than that of the other defendants. Joint trial of defendants with markedly varying degrees of involvement and culpability presents an acknowledged risk of prejudice, id. at 539, 113 S.Ct. 933, but in a particular case the district court may properly conclude that the risk can be addressed by means other than severance, such as curative jury instructions. Id. As a practical matter, disparity among the defendants in extent of involvement and culpability is commonplace in conspiracy cases and does not alone show the kind of prejudice that would require a district court to sever, rather than to respond with some less drastic measure such as a curative instruction. See Frazier, 280 F.3d at 844; United States v. Lee, 374 F.3d 637, 646 (8th Cir.2004) (“It is not an abuse of discretion to deny a severance motion when not every joined defendant has participated in every offense charged ... or when there is varying strength in the evidence against each defendant.”). Here, the district court instructed the jury to try each defendant solely on the evidence applicable to that defendant. Rusty Richards has given us no reason to conclude that this was not an adequate safeguard in his case or that the district court abused its discretion in refusing to sever. IV. Jury Selection Issues. Blue Bird argues that her case should be reversed because of the district court’s refusal to strike a venire-member for cause. This argument need not detain us, for the record shows that the venire-member, Pat Schommer, did not serve on Blue Bird’s jury. Even if Blue Bird used one of her peremptory challenges to strike Schommer, the jury that convicted her did not contain the venire-member she complains was biased, and therefore Blue Bird has not been deprived of any constitutional right. See United States v. Martinez-Salazar, 528 U.S. 304, 317, 120 S.Ct. 774, 145 L.Ed.2d 792 (2000); United States v. Nelson, 347 F.3d 701, 710 (8th Cir.2003). Blue Bird and Marvella Richards contend that the government violated the equal protection clause by making a peremptory challenge to venire-member Ethel Kills Straight, a Native American, with the motivation of eliminating her because of her race. Under Batson v. Kentucky, 476 U.S. 79, 106 S.Ct. 1712, 90 L.Ed.2d 69 (1986), if a defendant claims that the prosecution exercised a peremptory challenge based on the venire-member’s race, the trial court must proceed in three steps: First, the defendant must make a prima facie case that the prosecution’s strike was motivated by race; second, the prosecution must offer a race-neutral reason for the strike; and third, taking into account all the evidence, the trial court must find whether or not the prosecutor was motivated by purposeful discrimination. Snyder v. Louisiana, — U.S.-, 128 S.Ct. 1203, 1207, 170 L.Ed.2d 175 (2008). We review the trial court’s factual determination for clear error. Id. In this case, at voir dire, the court read off a list of potential witnesses and asked the venire whether they knew the witnesses. Kills Straight stated that she knew Melvin Sierra and Darwin Apple and Apple’s wife Babette Thin Elk. In fact, Darwin Apple was her husband’s nephew, and he and his wife typically came to Kills Straight’s Sun Dance. No one explained on the record what is involved in a Sun Dance or whether it has more than a social significance. When asked whether she could evaluate those witnesses’ testimony “just like anyone else that’s testifying,” Kills Straight answered, “Yes.” After the government exercised a peremptory challenge to strike Kills Straight, Blue Bird and Marvella Richards made a Batson challenge. The district court held that Kills Straight’s Native American race made a prima facie case under Batson, and so the burden shifted to the government to come forward with a race-neutral reason for its challenge. The prosecutor stated that Kills Straight had a familial relationship with two witnesses who were proposed character witnesses for Blue Bird and also attended Sun Dances with them, which might make her more willing to believe those witnesses. At that point, Blue Bird’s lawyer offered to stipulate that he would not call any of the three witnesses Kills Straight knew if the government would withdraw its challenge. The prosecutor did not accept that offer, and the district court ruled that Kills Straight was the only juror who had a familial relationship with defense witnesses, which was a valid, race-neutral reason for the prosecutor to strike her. The district court denied the Batson motion, finding: I believe the government has met their burden of stating a reason that is not race-based for striking Ms. Kills Straight. As I recall, Ms. Kill Straight is the only one who had a familial relationship with any of the witnesses who are identified. And although Ms. Schommer knew some of the witnesses, it was based solely on a business relationship. And if I recall correctly, the witnesses that she was familiar with were both government and defense witnesses. Ms. Kills Straight only knew witnesses that were being called by the defendant, so I find that the government has met their burden and the motion for the Batson challenge is denied. Blue Bird and Marvella Richards contend that the prosecution’s avowed reason for striking Kills Straight is pretextual because Schommer also knew potential witnesses and the government did not strike her. The district court found that Schommer and Kills Straight were not similarly situated because only Kills Straight was related to the witnesses. The government was entitled to surmise that blood is thicker than water. Moreover, Schommer had business relationships with witnesses for both sides, whereas Kills Straight only knew defense witnesses, which indicated a greater potential for pro-defendant bias on Kills Straight’s part. Accordingly, the district court held that the evidence did not establish that the prosecution had acted out of purposeful racial discrimination. These findings are not clearly erroneous. Blue Bird and Marvella Richards also argue before us that Blue Bird’s proposed stipulation not to call the witnesses eliminated the government’s reason for striking Kills Straight. They point to no authority that the government was obliged to accept such a stipulation after voir dire was over, and we decline to adopt a new rule that the government must negotiate its peremptories or run afoul of Batson. V. Discovery Issue. Blue Bird contends that the government failed to comply with Fed.R.Crim.P. 16(a)(1)(E) by failing to produce a copy of the warrant used to search Blue Bird’s blue trailer in the Igloos, on December 21, 2005. The prosecutor contended that she had not produced the warrant and accompanying affidavit because there was an issue about protecting the identity of a juvenile in a related case, but that she had produced a copy of Agent Derrick Hill’s report outlining the contents of the warrant. The district court inquired whether defense counsel had in fact received the report, and Blue Bird’s counsel said he could not represent to the court that he had not received the report, but he moved to suppress the fruits of the search on the ground that the search violated the Fourth Amendment. The district court did not hold Blue Bird to the terms of Fed. R.Crim.P. 12(b)(3)(C), requiring motions to suppress to be made before trial, but instead considered the motion to suppress on its merits. Because Blue Bird’s counsel maintained that Blue Bird had moved out of the trailer six months before the search and had no control over the trailer, the district court held that she had no standing to object to the search on Fourth Amendment grounds. Because other defendants objected, however, and it appeared they might have standing, the district court held a suppression hearing. After the suppression hearing, the court held that the government had not failed in its duty under Fed.R.Crim.P. 16(a)(1)(E) by failing to produce the warrant because it produced a copy of Derrick Hill’s report describing the warrant and search, which would have informed the defendants of the existence of the warrant; the search warrant itself was a public record, which was available to the defendants in the court files without the need for the government to produce it; and the government produced pictures of all the seized evidence before trial, as required, and the defendants did not move to suppress the evidence. Moreover, reaching the merits, the court held that Blue Bird lacked standing to object to the search of the trailer, even though she held title to it, because she was not living there and apparently others were, so that Blue Bird was like a landlord who is not occupying the property. The court held that even if some statements in the affidavit supporting the warrant were deemed untrue, the warrant would still have been supported by probable cause, and in any case, the agents acted in good faith in executing the warrant. The district court’s decision not to exclude evidence under Rule 16 is renewable for abuse of discretion. United States v. Tibesar, 894 F.2d 317, 319 (8th Cir.1990). Subsidiary factual findings are reviewed for clear error. Id. The district court found that the government produced a report that should have alerted the defendants to the existence of the warrant, which was a public record, see United States v. Bremer, 482 F.Supp. 821, 825 (W.D.Okla.1979), and that the government also properly produced pictures of the evidence seized pursuant to the search. Moreover, in light of the court’s waiver of the requirement that suppression motions be made before trial and the court’s findings that the search and warrant were lawful, the defendants cannot show they were prejudiced by the fact that their lawyers were apparently unaware of the search until Hill testified about it at trial. Blue Bird has by no means shown that the district court abused its discretion in permitting the government to introduce evidence concerning the fruits of the search. VI. Evidentiary Issues. A. Co-conspirator Statements. Blue Bird argues that the district court admitted some twenty statements as non-hearsay under Fed.R.Evid. 801(d)(2)(E) without making individualized findings that the statements were made during the course of the conspiracy and in furtherance of it, as required by the Rule. More specifically, the Rule requires that in order to admit such statements, the district court find by a preponderance of the evidence that a conspiracy existed involving the de-clarant and the party against whom the statement is offered and that the statements were made by the declarant in the course of and in furtherance of the conspiracy. Bourjaily v. United States, 488 U.S. 171, 175, 107 S.Ct. 2775, 97 L.Ed.2d 144 (1987). These extensive foundational requirements of Rule 801(d)(2)(E) would pose a logistical problem in ordering the evidence if the proponent had to establish each premise before being allowed to introduce the statements themselves. In United States v. Bell, 573 F.2d 1040, 1044 (8th Cir.1978), we prescribed the procedure appropriate when a party offers a statement into evidence that would be hearsay if it did not meet the requirements of Rule 801(d)(2)(E). In such a case (and upon objection), the district court may caution the parties, outside the hearing of the jury, that the statement will be admitted conditionally, subject to the proponent establishing the foundational elements during the course of trial. Bell, 573 F.2d at 1044. At the conclusion of the evidence, the district court must then make an explicit finding as to whether the proponent established the foundational elements; if not, the district court must determine the proper remedy, which may be an instruction striking the conditionally admitted statements or, where necessary, a mistrial. Id. In this case, at the pre-trial conference the district court outlined the Bell procedure and declared her intent to follow it, then repeated the discussion outside the hearing of the jury in response to a hearsay objection at trial. At that time, the court found that the government had established that there was a conspiracy. At the close of the evidence, the court stated that she was making her Bell finding. She stated the Rule 801(d)(2)(E) foundational elements, then said, “In those instances where I overruled the objections [during trial], I specifically found by overruling the objection that the declarations were made during the course [and in] furtherance of the conspiracy.” She also stated that she had upheld some objections at trial because she found that the declarations in question had not been made in furtherance of the conspiracy. Blue Bird now argues that the district court erred in not making specific findings as to each of the twenty statements. Blue Bird, however, does not point out any particular statement as to which the foundational requirements were not met, nor does she contend that she argued to the district court that the court had not complied with Bell. We do not apply Bell mechanically to compel reversals where no prejudice is shown. United States v. Cazares, 521 F.3d 991, 998 n. 5 (8th Cir.2008) (substantial compliance with Bell is sufficient); United States v. Roulette, 75 F.3d 418, 424-25 (8th Cir.1996). Blue Bird has neither identified any particular statement as to which the foundational elements are missing, nor has she shown any prejudice she suffered from the lack of a specific ruling as to each statement. Blue Bird’s own argument suffers from the very same defect of generality about which she complains — the twenty statements are lumped together in her brief, with no particular argument about particular statements. Blue Bird’s descriptions of the statements show that many were patently in furtherance of the conspiracy, being statements facilitating commerce in drugs or guns. Blue Bird may not put the burden on this court to sift through her undifferentiated argument in search of error. See United States v. Vanhorn, 296 F.3d 713, 717 (8th Cir.2002). She has not shown an abuse of discretion. B. Bruton Issue. Spotted Elk contends that there was a violation of his Sixth Amendment right to confront the witnesses against him when Dawnee Frogg testified that she and Blue Bird had a conversation while they were in jail concerning “what to say” and the need to “keep it between her [Blue Bird], Colin [Spotted Elk], Justin Hawk [Wing] and Sage [Richards].” Frogg said Blue Bird told her to say that Blue Bird’s money came from “the powwows, and her sugar shack, [and] her embroidery machine,” whereas Frogg said that in fact Blue Bird’s money came from drugs. Because Blue Bird did not testify at trial, Spotted Elk could not confront her about this conversation, and he moved for a mistrial on this basis, which the district court denied. In Bruton v. United States, 391 U.S. 123, 135-36, 88 S.Ct. 1620, 20 L.Ed.2d 476 (1968), the Supreme Court held that introducing an out-of-court confession by a non-testifying defendant violated the Confrontation Clause rights of a co-defendant who was incriminated by the statement. In the years since Bruton, the Supreme Court has clarified the scope of the Confrontation Clause in Crawford v. Washington, 541 U.S. 36, 53-54, 124 S.Ct. 1354, 158 L.Ed.2d 177 (2004), Davis v. Washington, 547 U.S. 813, 821-22, 126 S.Ct. 2266, 165 L.Ed.2d 224 (2006), and Giles v. California, — U.S. -, 128 S.Ct. 2678, 171 L.Ed.2d 488 (2008). It is now clear that the Confrontation Clause does not apply to non-testimonial statements by an out-of-court declarant. Davis, 547 U.S. at 823-26, 126 S.Ct. 2266; Whorton v. Bockting, 549 U.S. 406, 127 S.Ct. 1173, 1183, 167 L.Ed.2d 1 (2007) (“[T]he Confrontation Clause has no application to [non-testimonial out-of-court statements]”). Blue Bird’s reported utterance was not a statement of fact, but a proposal of a future course of action (i.e., what to say in the future), uttered not to any official, but to a co-defendant. See Davis, 547 U.S. at 822, 126 S.Ct. 2266 (testimonial statements describe past events); United States v. Singh, 494 F.3d 653, 658-59 (8th Cir.) (co-conspirators’ statements in furtherance of the conspiracy were not testimonial under Crawford), cert. denied, — U.S.-, 128 S.Ct. 528, 169 L.Ed.2d 368 (2007). Blue Bird’s reported words were not testimonial, and therefore Frogg’s account of them could not violate Spotted Elk’s Sixth Amendment rights. C. Police Officer Testimony. Blue Bird contends that various police officers rendered opinions for which there was no adequate foundation. We review the district court’s admission of evidence for abuse of discretion. Old Chief v. United States, 519 U.S. 172, 174 n. 1, 117 S.Ct. 644, 136 L.Ed.2d 574 (1997). Blue Bird contends that Detective Tony Harrison was allowed to testify without personal knowledge (1) that the reason the cash found in the Ramada Inn was wrapped in Saran wrap was to mask the odor of substances on the bills to prevent detection by police dogs; (2) that the reason there was a layer of grease outside the packaging for cocaine was also to mask the smell; and (3) that little pieces of tinfoil found in the Ramada Inn were used to smoke cocaine. At the time of trial, Harrison had been a police officer for ten years and was assigned to the Unified Narcotics Enforcement Team. Harrison testified at length about his training and experience in investigating drug cases, including hundreds of hours of training by the Bureau of Alcohol, Tobacco and Firearms and the Drug Enforcement Agency. Federal Rule of Evidence 702 permits a district court to allow the testimony of a witness whose knowledge, skill, training, experience or education will assist a trier of fact in understanding an area involving specialized subject matter. It is well within the discretion of a district court to allow law enforcement officials to testify as experts concerning the mo-dus operandi of drug dealers in areas concerning activities which are not something with which most jurors are familiar. United States v. Solorio-Tafolla, 324 F.3d 964, 966 (8th Cir.2003) (internal quotation marks and citations omitted). Harrison established that he had the expertise necessary to assist the jury in understanding how the pieces of evidence found in the course of the search of the Ramada Inn and Blue Bird’s house would have been used by drug dealers and users. Therefore, he was correctly permitted to testify about how the items would typically be used by drug users and dealers, although he had no personal knowledge that the particular items in question had in fact been so used. The usefulness of Harrison’s testimony was not outweighed by the dangers of unfair prejudice, confusion of issues, or misleading the jury. See Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 595, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993). The district court did not abuse its discretion in admitting it. Blue Bird also argues that the district court erred in admitting the expert testimony of Jon Dicks about the fingerprints on the Tupperware containers without first conducting a Daubert hearing. The record shows that before ever eliciting an opinion, the prosecutor established that Dicks had received extensive training in fingerprinting and that his methods were “accepted in the scientific community, in the law enforcement community, and the legal system.” Moreover, later in Dicks’ testimony, he said that his work in this case was peer-reviewed by a nationally recognized fingerprint examiner, Sergeant Detective Jordahl. Blue Bird does not point to anything questionable about Dicks’ methodology or the underlying science he employed; “Fingerprint evidence and analysis is generally accepted.” United States v. Collins, 340 F.3d 672, 682 (8th Cir.2003); accord United States v. Janis, 387 F.3d 682, 689 (8th Cir.2004). A Daubert hearing is not required where the record already establishes that the testimony is admissible. See Solorio-Tafolla, 324 F.3d at 965-66. “When a district court is satisfied with an expert’s education, training, and experience, and the expert’s testimony is reasonably based on that education, training, and experience, the court