Full opinion text
Opinion KENNARD, J. A jury convicted defendant Jon Scott Dunkle of the first degree murders of 15-year-old John Davies and 12-year-old Lance Turner, finding true a multiple-murder special-circumstance allegation and weapon-use enhancement allegations. (Pen. Code, §§ 187, 190.2, subd. (a)(3), 12022, subd. (b).) After a penalty trial, the same jury returned a verdict of death. This appeal is automatic. (§ 1239, subd. (b).) We affirm the judgment. I. FACTS A. Guilt Phase 1. Disappearance of John Davies In November 1981, defendant, then 21 years old, was a close friend of the Davies family, who lived in Belmont. He often visited the Davies residence and spent time with 17-year-old Mark Davies and his 15-year-old brother John. On the morning of Sunday, November 8, 1981, James Davies called the police to report his son John missing. Davies and his wife, Joan, had returned home around 1:30 a.m. and had noticed nothing amiss. Joan had found John missing when she opened his bedroom door sometime after 8:30 a.m. John had laid out his church clothes and had left behind all his possessions, including his only pair of shoes. He usually informed his parents of his whereabouts and, according to them, was not the sort of child who would be expected to run away. James and Joan Davies unsuccessfully made extensive efforts to locate John for several years after he disappeared. Soon after the disappearance, James Davies called defendant to come over and help post flyers describing John. Defendant came over on the Wednesday or Thursday after the Sunday John was reported missing, and left with some flyers. He never visited the Davies family again. Mark Davies testified that before John disappeared, defendant would come by the Davies residence in his white Honda automobile. If he came to visit in the evening, he would throw rocks at Mark’s window so Mark could sneak out of the house without his parents’ knowledge. They would drive to the Hassler Hospital site off Woodside Road and Highway 280 to explore the partially abandoned grounds. Mark last saw his brother John on Saturday, November 7, about 10:30 p.m., when Mark went to bed. Mark never heard from defendant after John’s disappearance. Joan Davies testified that when defendant visited her sons, they would often sit in defendant’s car listening to music. Initially, police theorized John had run away. Belmont Police Detective Jerrold Whaley contacted defendant in mid-1982, and defendant told him where John liked to hang out. Because the Davies family reported that defendant was John’s closest friend, Whaley contacted defendant often. By September 1984 the police were treating the disappearance as a possible kidnapping and had contacted the Federal Bureau of Investigation (FBI) for assistance. On December 4, 1984, Whaley and FBI Agent Robert Deklinski twice interviewed defendant at his residence near Sacramento. In the first interview, defendant denied seeing John on Saturday, November 7, 1981, claiming he did not leave his parents’ home that evening, and denied ever throwing rocks to summon Mark or John and sitting in his car listening to music with John. In the second interview, Whaley and Deklinski probed the discrepancies between the Davies family members’ and defendant’s accounts; defendant was emphatic that he had neither thrown rocks at the boys’ bedroom windows nor listened to music with John in his car. Defendant also denied he had ever traveled with John to a hangout he called the “morgue,” evidently the Hassler Hospital grounds. 2. Murder of Lance Turner On October 2, 1984, about 7:00 p.m., Belmont resident Margaret Turner called the police to report her 12-year-old son, Lance, missing from soccer practice. That day, Timothy O’Brien had driven his two sons and Lance to soccer practice at the fields behind Ralston Intermediate School. O’Brien began coaching his team and did not see Lance again. Later, when the practice ended, O’Brien asked Lance’s coach, Ray Williamson, where Lance was. Williamson told him Lance was not at practice that day. Several boys reported seeing Lance head toward Waterdog Lake, three-eighths of a mile from the soccer field. A search followed. William Russell arrived at 6:00 p.m. to pick up his son from soccer practice and, after taking his son home, joined the search for Lance. About 8:20 p.m., Russell shined a flashlight onto some bushes in a gully off the path to Waterdog Lake and saw feet sticking out of the bushes. Lance’s body was found under the overgrown brush. Pathologist Peter Benson, M.D., testified Lance had died from blood loss due to multiple stab wounds. Two wounds to the heart were each fatal; two other wounds to the lungs were potentially life threatening. There were numerous defensive wounds to the arms and hands, as well as scratches, scrapes and bruises. Stephanie Olson, Kendra Durham, and Nicole Guthrie, students at Ralston Intermediate School at the time of the Turner homicide, testified that about 3:00 p.m. on October 2, 1984, they left school, skipping volleyball practice, and went down to Waterdog Lake to smoke cigarettes. A man whom Stephanie described as having dirty blond hair, pimples, and dirty teeth with a retainer approached them and started a conversation. He told them his name was Jon and said he had graduated from Carlmont High School the year before. He was drinking beer from a tall Budweiser can, which he offered to the girls. The girls left after about 20 minutes. Another Ralston student saw a man with dirty blond hair near Waterdog Lake about 4:00 p.m. (None of these witnesses was asked to identify defendant in the courtroom. Olson, Durham and Guthrie gave the police a description of the man that was incorporated into a composite drawing used in the investigation of the Turner homicide. As discussed below ¡post, at p. 874], in his confession to FBI agents, defendant described talking with the three girls shortly before he killed Turner.) 3. Investigation of Davies and Turner murders On December 27, 1984, Belmont Police Detective Sergeant James Goulart interviewed defendant concerning the Turner homicide. Defendant was by then the only suspect in the crime. Detective Goulart advised him of his constitutional rights, and he agreed to speak with Goulart. Defendant denied having been at Waterdog Lake on October 2, 1984, claiming he had been at home until noon and then had gone to stores in Redwood City to fill out employment applications, returning home by bus at 4:30 p.m. Later police contacts with those businesses turned up no such applications. In January 1985, in an effort to gather information about the Turner homicide, Belmont Police Officer Lisa Thomas began working undercover at the Sacramento Carl’s Jr. restaurant where defendant was employed. There she encountered defendant several days a week, regularly visited him at his sister’s house, where he was residing, and sometimes went to a bar or movie with him. Defendant often spoke with Thomas about newspaper reports on the investigations, at one point showing her a collection of clippings. On February 9, 1985, defendant told her the police and the FBI had been in his home for five hours, confronting him, and that he had lied to them. To Thomas, he maintained his innocence, claiming that on the day Turner was killed he had gone to Redwood City to fill out job applications. Defendant seemed impressed with the attention he was getting from the FBI. In May 1986, James and Joan Davies met with defendant for several hours seeking information about John. Defendant said he had none. Joan Davies met with defendant again in July 1986, and he continued to insist he had no information. On September 16, 1986, Charles Rice told Michael Wiley, a law enforcement investigator for the State of California, that defendant had admitted to killing John Davies and Lance Turner. (During the penalty phase, the jury was informed that Rice was defendant’s cellmate at the state prison in San Luis Obispo on that date. Defendant was then incarcerated on a burglary conviction arising out of an incident, discussed post, at pages 921-923, in connection with a related appellate contention.) Wiley testified that Rice voluntarily made a statement, asking nothing in return, and insisted on trying to obtain further information from defendant because he was appalled by the killings. On September 22, 1986, Rice gave investigators two maps, drawn by defendant, of the crime scenes. A week later, defendant met with Rice, who was wearing a wireless transmitter, and described the Davies and Turner murders in graphic detail. Defendant refused to report the crimes to the Belmont police because he did not trust them. He said he did trust the FBI, however, so Rice told defendant he had a friend who was an FBI agent and would help defendant if he confessed to him. Prison officials arranged to find an FBI agent to take the confession. On October 3, 1986, FBI Special Agents Frank Hickey and Daniel Payne interviewed defendant at the state prison in San Luis Obispo. Rice was also present. Defendant was advised of his constitutional rights and signed a waiver. Defendant stated that, before killing John Davies, he was at Half Moon Bay with three friends, drinking whisky and smoking marijuana. He then drove to the Davies residence, parked a few doors down the street, and entered through an unlocked door. He went to John’s bedroom and invited him to come and drink beer. John agreed, and went with defendant to Edgewood Park in Redwood City near the Crystal Springs Reservoir. John was wearing a black T-shirt, blue corduroy pants and no socks or shoes. Defendant parked near a shooting range and, before leaving the car, removed a knife from the glove compartment. At that point, he “committed” himself to killing John. They walked half a mile to two miles down a dirt road. Defendant then stabbed John in the back, sat on his chest and stabbed him in the throat. When John struggled, defendant picked up a large rock and struck him in the head. Defendant then dragged the body to an opening in the ground, pushed it in and left the scene, later disposing of his bloodstained clothing. A week after the murder, defendant returned to the area and observed that the body was bloated and animals were feeding on it. In May 1984, he returned again and observed a skull. Asked about a motive for killing John Davies, defendant said that when he drank beer and smoked marijuana he became aggressive. He also noted that John used to cause a computer monitor to flash irritating statements that defendant would observe, and this angered him. Defendant drew a map for the investigators illustrating the location of John’s remains. Regarding the murder of Lance Turner, defendant stated that on October 2, 1984, he was in the process of moving from Belmont to another part of the state. On that day, he bought a six-pack of beer and went to the park near Waterdog Lake to drink it. At 2:30 p.m., after some three hours at the lake, he went to an area near Ralston School. He climbed a tree known as the “smokers’ tree” and used his buck-type hunting knife to stab at it. Three junior-high-school-age girls came to the tree looking for a pack of cigarettes and dug up a matchbook with a distinctive inscription. The girls shared defendant’s last beer and one of them offered him a marijuana cigarette. At one point defendant saw a boy wearing athletic clothes run down the hill. After the girls left, defendant stayed for another five minutes. Then, as he headed back toward the dock, he saw the boy jogging in the area. To get his attention, defendant asked him the time. The boy responded that it was 3:50, and turned away. As he turned, defendant stabbed him in the side with his hunting knife. The boy struggled as defendant stabbed him a second time, then went down to the ground and complied with defendant’s command to put his leg down. In the course of the struggle, the boy bit defendant so severely on the thumb that he later lost the nail. Defendant stabbed him again, in the throat, and yet a fourth time near the heart. The boy then appeared dead. Defendant moved the body under some low bushes and went home. He later disposed of the knife and sheath in separate places and discarded his shoes out of concern that their prints could be identified. He correctly described a birthmark on the side of the boy’s neck. Using a map defendant had drawn, Belmont police searched for John Davies’s remains and found items of clothing, bones and a skull. A forensic pathologist who examined the skull testified it was consistent with that of a young Caucasian male and bore evidence of blunt force trauma that could have been inflicted by a rock. Orthodontist Stan Wolken compared X-rays of his patient, John Davies, with X-rays of the remains, finding similarities between them. On October 6, 1984, defendant led investigators into a field near a Carmichael residence and pointed out the shrubbery where he had discarded the knife he had used to kill Lance Turner. With the help of a metal detector, investigators found a folding Puma brand knife. On two occasions in October 1986, for 45 minutes and five hours respectively, Psychiatrist James Missett, met with defendant at the request of the district attorney’s office. Dr. Missett read defendant his constitutional rights at the outset of each interview and defendant waived them. Defendant described having an interest in reading newspaper accounts of killings when he was in elementary school. He stopped doing so in fifth grade because “homicides weren’t part of my everyday scene.” In sixth grade, defendant became aware that he wanted to kill someone after watching a movie in which an older boy was about to kill a younger boy to prevent him from disclosing a diary containing references to other murders. About the Davies murder, defendant said: “I thought to myself[,] you have got someone out in the middle of nowhere, here is your chance to kill someone. You have thought of killing someone before.” After describing how he initially stabbed Davies, defendant told Dr. Missett he pinned Davies down with his knees on his shoulders and, when Davies asked what he planned to do, defendant said he was going to kill him. He told Davies to scream all he wanted before stabbing him in the throat and strangling him with his hands. Defendant said he stopped to think whether he wanted to go through with it before he picked up a rock and hit Davies three times on the right side of the head. B. Penalty Phase 1. Prosecution case in aggravation The prosecution introduced evidence that defendant had attempted, in separate incidents, to kill Steve Muiphy and Monte Hansen, and had murdered Sean Dannehl. The prosecution also presented evidence, described below in connection with related contentions (see post, at pp. 918-920), of defendant’s threat to kill jail nurse Angela Beck and his burglary of the home of Richard Rennie. a. Attempted murder of Steve Murphy On November 5, 1982, 16-year-old Steve Murphy attended a party at a friend’s house in San Mateo. Leaving the party around 11:30 p.m., he walked another friend home. Murphy was heading toward his own residence, 15 to 20 houses away, when he lost consciousness. He awoke after daylight the next morning near a large dirt area surrounded by trees. He fell unconscious again and next woke up in a hospital, discovering that his spleen and a kidney had been surgically removed. He spent the next three weeks in the hospital with broken ribs and a broken pelvis. His injuries caused him to miss several months of school. In October 1986, after obtaining a waiver of constitutional rights, Belmont Police Officer Joseph Farmer spoke with defendant about the assault on Murphy. Defendant admitted he had been drinking alcohol on the beach before driving his car up the hill on 42d Avenue in San Mateo. He saw someone walking on 42d Avenue and made two or three right turns to encounter the person again. He deliberately ran over the person, put him in the back of his car, and drove him to an isolated area in Belmont at the Marburger turnaround. He took the person out of the car and laid him on the roadway. Defendant referred to the person as “Steve Murphy,” but did not explain how he had learned the victim’s name. b. Attempted murder of Monte Hansen In 1982, Monte Hansen, then 16 years old, often went out drinking with defendant. On New Year’s Eve that year, Hansen invited defendant to come to his house, as his parents were out. Defendant arrived shortly before midnight, apparently under the influence of alcohol, and told Hansen he felt dizzy. Hansen told him to drink some water and went out into the backyard to smoke a cigarette. There, he turned to observe defendant approaching him, a two-by-four-inch board studded with nails in his raised hand. Defendant struck at Hansen with the board. One blow hit him in the head, but Hansen blocked the rest of the blows with his forearm. Defendant was smiling as he attacked Hansen. Defendant then reentered the house and Hansen saw him put a knife back in a kitchen cabinet. Hansen screamed at defendant to get out and told defendant he would kill him if he harmed his little brother, who was asleep in a bedroom. Defendant ran toward his car and Hansen never saw him again. On February 28, 1985, undercover officer Lisa Thomas told defendant a false story about her involvement in a hit-and-run accident. Defendant then told her how he had run over Steve Murphy and assaulted Monte Hansen; a recording of the conversation was played for the jury. c. Murder of Sean Dannehl Around 6:00 p.m. on July 2, 1985, 12-year-old Sean Dannehl went to a friend’s house in Sacramento, riding his bicycle. When he did not return home by 9:00 p.m., his mother called the friend’s house and learned Sean had left around 7:30. His father and mother and her husband searched for him. His body was found six days later at Lower Sunrise Park. A board with a nail in it and a beer can were found at the scene. An autopsy revealed the cause of death to be two stab wounds to the heart, one penetrating a rib, caused by something thick, pointed and dense, consistent with a marijuana pipe tool. Sean also suffered a perforating wound to the skull consistent with the nail-embedded board. Insect activity in the facial and neck area also suggested the presence of some type of wound there. Sacramento Detective Robert Bell questioned defendant on July 5, 1985. Defendant said he did not know about the missing boy, but he admitted that on July 2 he was on a bicycle trail at Lower Sunrise Park drinking beer with friends until about 8:30 p.m., when he rode home. He claimed a flat tire prevented him from arriving at home before 10:00 p.m. Anton Martinez and Paul Stanley confirmed they were on the bicycle trail with defendant that day, drinking beer and smoking marijuana until they parted around sunset. After Sean’s body was found, Detective Bell contacted defendant, who agreed to accompany investigators to the police station. After waiving his constitutional rights, defendant denied knowing anything about Sean’s murder. Investigators drove defendant to his sister’s residence, where he was staying. Defendant and his sister agreed to a search of the house; no evidence was found. Defendant later voluntarily returned to the police station to provide hair, blood and saliva samples. The next day, July 10, 1985, defendant showed Detective Bell where on the bicycle trail he had had a flat tire and where he and his friends had met to drink beer. Defendant also assisted investigators in searching for his missing marijuana pipe tool, accompanying them to several smoke shops and finding one tool he said resembled the one he had lost. On July 15, 1985, defendant telephoned Detective Bell to tell him Paul Stanley’s blood might be found on his (defendant’s) bicycle because Stanley had fallen and might have bled on it. On August 19, 1985, in an effort to get defendant to confess, undercover narcotics officer Ronald Goesch, posing as “Ron Cross,” left a letter at defendant’s house. The letter advised that Cross lived near the river, the police were pressuring him, and he knew what defendant had done and would be communicating with him again. Defendant gave the letter to Detective Bell. Officer Goesch left another letter and called defendant four days later, asking to meet with him. Goesch said he knew about “the board” and “other stuff,” and wanted money or he would go to the police and give them evidence, adding that he needed the money to avoid his own arrest. Defendant did not respond and did not appear at the time Goesch requested. After investigators questioned defendant about the Ron Cross information, defendant telephoned Detective Bell, upset at the course of the investigation. In the course of the conversation, defendant asked, hypothetically, what might happen if he confessed to the crime. He also asked, hypothetically, if he were at the scene, saw the victim screaming and took no action to save him, whether his inaction would get him in trouble. Department of Corrections Sergeant Michael Wiley took Charles Rice’s report of defendant’s confessions. On September 28, 1986, in Wiley’s office, Wiley overheard defendant describe to Rice, who was wearing a wireless microphone, the murders of Lance Turner, John Davies and Sean Dannehl. On October 3, 1986, following defendant’s agreement to confess to the murders to the FBI (see ante, at p. 874), FBI Special Agents Frank Hickey and Daniel Payne asked defendant about the Dannehl murder. Charles Rice was also present during the interview. Defendant stated that on July 2, 1985, he had left his home at 11:30 a.m. and ridden his bicycle to the American River Park, where he met an acquaintance, Anton. They bought some beer and went to Anton’s house, where another friend met them. The three rode their bicycles back to the park and smoked marijuana and continued to drink beer. Defendant drank four tall beers and three 12-ounce cans of beer. About 8:30 p.m. they parted, and defendant rode his bicycle to a vista point. He saw Sean Dannehl riding his bicycle towards Sunrise Boulevard, commenting to Agent Hickey, “I knew right then I was going to stop him and kill him.” He chased after Sean, ramming Sean’s bicycle with his own. When Sean fell off his bicycle, defendant grabbed his arm and led him to a large tree. Sean cooperated, causing defendant to want to humiliate him, over Sean’s pleas that defendant not hurt him. Defendant forced Sean to take off his clothes and put them in a pile. A two-by-four lay in the area; defendant put it over Sean’s eyes as he lay on his back. Defendant was carrying an electrician’s instrument with a pick, which he thrust into Sean’s chest, near his heart. After Sean protested that defendant had promised not to hurt him, defendant put a hand over his mouth and stabbed him again, causing the blade of the instrument to separate from the handle. Defendant retrieved the blade, screwed it back into the handle and stabbed Sean in the eyes. He then rode his bicycle home, removing the handle from the pick along the way and discarding the pieces separately. At home, defendant washed his clothes and buried his bloody socks in a flowerbed near a library three blocks from his house. He signed a written statement incorporating his confession, drew a map of the crime scene, and gave investigators a sketch of his pick tool. 2. Defense case in mitigation The defense presented the testimony of a forensic psychiatrist, George Wilkinson, M.D., who had been appointed by the court on two occasions to evaluate defendant’s competency to stand trial. Dr. Wilkinson had reviewed records of defendant’s treatment in correctional mental health facilities, as well as police and school reports, and testified regarding his observations of defendant’s behavior, personality and thought processes, his diagnoses of defendant’s mental condition, and his conclusions regarding how that condition had worsened over the two years during which he performed his evaluations. Based on his initial evaluation in 1987, Dr. Wilkinson believed defendant was not psychotic but had experienced psychotic episodes in the past; also, he was manipulative and malingering to some degree. Accordingly, Dr. Wilkinson diagnosed defendant as having antisocial personality disorder with transient psychotic episodes. Later contacts with defendant, who by then was relating obviously delusional thoughts and engaging in bizarre behavior, caused Dr. Wilkinson to alter his diagnosis to paranoid schizophrenia with antisocial personality traits. Dr. Wilkinson estimated defendant’s intelligence quotient to be low normal, or no higher than 90. By judicial notice, the jury was informed that the defense in this case had never entered a plea of not guilty by reason of insanity. 3. Rebuttal Psychiatrist James Missett, testified that in October 1986 he examined defendant on two occasions after obtaining a waiver of constitutional rights. Defendant acknowledged that before he killed John Davies he had long wondered what it would be like to kill another human being. Dr. Missett noted that defendant’s mental processes after the Davies homicide were clear enough to enable him to take steps to avoid being caught, such as washing up and disposing of his bloodstained clothing and denying any knowledge of John’s whereabouts to the Davies family. Dr. Missett diagnosed defendant as having, at the time of all three murders and since, a mixed personality disorder with antisocial, borderline and narcissistic traits, and sexual sadism. He saw no evidence to support a diagnosis of paranoid schizophrenia. Dr. Missett observed defendant during a May 1988 competency trial and interviewed him to evaluate his competency in July 1989 (see post, at pp. 881-882, concerning events leading to the competency proceedings), at which time defendant appeared to be consciously feigning mental illness. Although at times defendant gave candid and straightforward responses, at other times he disrupted the interview with gibberish and refused to discuss details of the killings. At one point he smiled at and maintained eye contact with Dr. Missett, unlike true schizophrenics, who characteristically are withdrawn. Dr. Missett concluded defendant had “a little mental illness . . . and a lot of malingering.” Dr. Missett characterized defendant’s behavior toward him and defense counsel, as well as defendant’s three murders and other assaults, as involving his hating and acting contemptuously towards persons he also in some way liked, respected or admired. Although defendant’s attraction to and hatred of prepubescent boys were outside his control, his devious planning and avoidance of detection for long stretches of time were within his control. To Dr. Missett, defendant’s criminal conduct reflected innate evil rather than mental illness. Dr. Missett offered no explanation for why defendant could ingest near-maximum doses of antipsychotic medications and display none of the sleepiness that would be expected if he were merely malingering. 4. Surrebuttal In lieu of testimony, the jury heard the parties’ stipulation that, if he were called to testify, Defense Counsel Douglas Gray would state that he was first appointed in July 1988, defendant having previously been represented by other attorneys; that from July to September 1988 defendant cooperated with Gray and discussed various aspects of the case with him; that from September 1988 through April 1989 defendant refused to cooperate with Gray by refusing to meet or discuss the case with him; that in April 1989 defendant began to cooperate with him selectively but still refused to discuss certain topics such as penalty and legal issues; that after a competency trial and during the trial of the offenses defendant refused to cooperate with him; that on several occasions in open court defendant expressed a desire to plead guilty to the charges; and that no such plea had been entered on his behalf. H. ANALYSIS A. Competency Issues 1. Factual background At several points after defendant was charged in this case and before his trial began, concerns arose over his competency to stand trial. We outline the relevant events. On May 27, 1987, one month after the information was filed, defendant was admitted to the psychiatric inpatient facility at Harold D. Chope Community Hospital (Chope Hospital) as gravely disabled under Welfare and Institutions Code section 5150 because he appeared to be experiencing delusions and hallucinations and wanted to kill himself. His diagnosis on admission was atypical psychosis. On June 2, 1987, he was discharged back to the San Mateo County Jail with a diagnosis of acute paranoid disorder. A little more than five months later, on November 3, 1987, the trial court suspended criminal proceedings and appointed two psychiatrists, Dr. Charles Casella and Dr. George Wilkinson, to examine defendant to determine his competence to stand trial. (§§ 1367, 1368.) The court also appointed a psychologist, Dr. Alfred Fricke, to perform tests. All three issued reports and a competency hearing was set. Shortly before the hearing, on May 6, 1988, defendant was again admitted to Chope Hospital under Welfare and Institutions Code section 5150 because his behavior was loud and bizarre, he was agitated and delusional, and he was exhibiting grandiose and paranoid ideas, looseness of associations, and disorganized thinking. His diagnosis on admission again was atypical psychosis. On May 16, 1988, he was discharged back to San Mateo County Jail with a diagnosis of chronic schizophrenia with acute exacerbation. That same day, his first competency hearing began, a jury having been waived. On May 19, 1988, the trial court found defendant competent to stand trial. On June 17, 1988, the trial court relieved Defense Attorneys Philip Barnett and Vincent O’Malley at defendant’s request (see People v. Marsden (1970) 2 Cal.3d 118 [84 Cal.Rptr. 156, 465 P.2d 44]) and denied defendant’s motion for self-representation (see Faretta v. California (1975) 422 U.S. 806 [45 L.Ed.2d 562, 95 S.Ct. 2525]). A week later, Trial Counsel Douglas Gray appeared on behalf of defendant. Eight months later, on February 16, 1989, defendant was again admitted to Chope Hospital under Welfare and Institutions Code section 5150 because he was exhibiting increasingly bizarre behavior, was delusional with loose associations and disorganized thinking, and was eating little and not showering. On admission, he was diagnosed with chronic paranoid schizophrenia, with acute exacerbation. That same day, counsel declared a doubt as to defendant’s competency, which the trial court treated as a motion under Penal Code section 1367 and denied. At the prosecution’s suggestion, the court appointed Dr. Wilkinson under Evidence Code section 730 to determine whether there had been any change in defendant’s condition since the May 1988 competency finding. On March 8, 1989, at the request of the prosecution and the defense, the court again suspended criminal proceedings under section 1367 and appointed a second psychiatrist, Dr. Roland Levy. Dr. Wilkinson’s and Dr. Levy’s reports were received on March 29, 1989. The prosecution requested a jury trial on the question of defendant’s competence. In light of Defense Counsel Gray’s status as a witness, Gordon Rockhill was associated as counsel for the second competency hearing, which began on July 24, 1989. On August 3, 1989, the jury returned a finding of competency. Some two and a half months later, on October 16, 1989, jury selection began in defendant’s criminal trial. 2. Claims pertaining to 1989 competency trial a. Assertedly erroneous admission of evidence Defendant contends the trial court erred in allowing, over defense objections at various points in the competency trial, irrelevant discussion and evidence of the factual details of the charged offenses. (Evid. Code, § 350.) Defendant further argues that any relevancy of these details was substantially outweighed by the prejudice they caused him before the competency jury, in violation of Evidence Code section 352 and his right to due process of law under the state and federal Constitutions. Defendant complains that, during voir dire, the prosecutor asked prospective jurors, “[I]f it were to come out during the testimony of the psychiatrists that because there are multiple murder charges against Jon Dunkle, some other judge and some other jury down the road—not you, nothing for you to consider . . . may have to consider the death penalty, do you have such strong feelings, one way or the other,” that it would affect them in the competency trial. The prosecutor later asked similar questions of other prospective jurors. Defense counsel objected that the penalty in the criminal trial was irrelevant to and remote from the issues in the competency proceeding, and that competency jurors should not be considering the issue of possible penalties. The trial court allowed the prosecutor to inquire. There was no error. A trial court enjoys wide latitude in determining what questions may be asked on voir dire, and its exercise of discretion in this respect forms grounds for reversal only when it renders the trial fundamentally unfair. (People v. Cleveland (2004) 32 Cal.4th 704, 737 [11 Cal.Rptr.3d 236, 86 P.3d 302].) Contrary to defendant’s assertion, the subject of penalty was relevant to the competency trial, in that the psychiatric experts’ testimony touched on defendant’s understanding of the potential outcome of the criminal proceedings and his possible motivation to delay them. Defendant suffered no undue prejudice by the prosecutor’s mention of the potential penalty during voir dire. (See People v. Padilla (1995) 11 Cal.4th 891, 925 [47 Cal.Rptr.2d 426, 906 P.2d 388] [for purposes of Evidence Code section 352, “undue” prejudice stems from evidence that “ ‘ “tends to evoke an emotional bias against the defendant as an individual” ’ ” and that has a negligible bearing on the issues, “not the prejudice ‘that naturally flows from relevant, highly probative evidence’ ”].) Defendant’s due process claim lacks merit for the same reasons. Defendant further complains of the admission of references to the uncharged killing of Sean Dannehl. First, defendant notes the prosecutor, out of the presence of the jury, stated that Dr. Missett and Dr. Wilkinson had discussed the Dannehl homicide with defendant and that he intended to bring up evidence pertaining to that offense because defendant would be “dealing with [it] during the penalty phase.” Defense counsel objected on grounds of irrelevancy and undue prejudice. The trial court ruled inadmissible any mention of the Dannehl homicide unless it became clear that the probative value of such evidence outweighed its prejudicial effect. Detective Robert Bell, a homicide investigator in the Sacramento County Sheriff’s Department who had worked on the Dannehl case, later testified for the prosecution without mentioning that case. Dr. Levy and Dr. Missett, in their respective testimony, referred to the existence of the Dannehl homicide, without describing any details of the offense. The determination of the extent of a defendant’s ability rationally to assist counsel in presenting a penalty defense may necessitate reference to evidence of uncharged offenses likely to be presented to the penalty phase jury. (See People v. Turner (2004) 34 Cal.4th 406, 427 [20 Cal.Rptr.3d 182, 99 P.3d 505]; People v. Medina (1990) 51 Cal.3d 870, 887-888 [274 Cal.Rptr. 849, 799 P.2d 1282]; People v. Samuel (1981) 29 Cal.3d 489, 494-496 [174 Cal.Rptr. 684, 629 P.2d 485].) Here, Dr. Missett testified that during the competency examination, defendant spontaneously referred to Sean Dannehl but refused to discuss the details of the offense; probing a defendant’s understanding of those details, Dr. Missett noted, was relevant to the competency determination. We therefore see no error in the references to the Dannehl homicide. Defendant additionally argues the prosecutor improperly brought the facts of the Turner and Davies homicides before the jury, causing prejudice requiring reversal of the judgment. During his opening statement to the competency jury, the prosecutor summarized the evidence of those offenses; when defense counsel objected, the prosecutor explained the evidence would show that defendant remembered what he had done in the course of the killings and related it to the evaluators. As promised, the prosecutor then presented the testimony of Belmont Police Officer Joseph Farmer, who related the substance of defendant’s 1986 confessions to the Davies and Turner homicides and the Murphy attempted murder. Specifically, Farmer testified defendant said that in 1984 he approached Lance Turner on a trail, stabbed him with a knife in the throat, stomach and chest, and dragged the body off the trail into the bushes; in November 1981 he invited John Davies to have some beer and listen to his car stereo, and then at Edgewood Park took a knife from his car, walked up a hillside with John, stabbed him in the back and throat, strangled him, hit him over the head with a rock, and pushed the body 100 feet off the side of the hill; and in 1982 he deliberately ran Stephen Murphy over with his car, put him into the car, drove him to another undeveloped part of Belmont and left him there. Defendant contends these facts were irrelevant to the issues involved in the competency trial, and that he never contested (as by a claim of amnesia or organic brain damage) that he remembered his actions. Contrary to defendant’s contention, the evidence of the homicides and attempted homicide served a legitimate purpose in the competency trial: to convey to the jurors the essence of the case against which defendant would have to defend himself, in order that they could assess his understanding of the charges and ability to assist counsel in his defense. The evidence, moreover, illuminated defendant’s failure to discuss the facts of the offenses with the mental health professionals appointed or retained to evaluate him, as contrasted with his earlier, more forthcoming admissions to law enforcement officers. This, in turn, tended to support the prosecution’s contention that defendant could rationally assist counsel, if he so chose. In any event, a minimum of time was spent on the facts of the homicides, and the jurors were instructed not to be biased against the defendant, or swayed by sympathy, passion, prejudice, or the possible consequences of their verdict. Because the trial court did not abuse its discretion in permitting references to the facts of the Turner and Davies homicides to come before the jury, defendant was not denied due process. (Cf. People v. Turner, supra, 34 Cal.4th at p. 427.) b. Sufficiency of evidence to support competency finding Defendant contends insufficient evidence supported the jury’s finding of his competency, that he was in fact incompetent, and that his trial while incompetent violated state law and his federal constitutional rights of due process, to the assistance of counsel and to be present during the proceedings against him. A person cannot be tried or sentenced while mentally incompetent. (§ 1367, subd. (a).) A defendant is mentally incompetent to stand trial if, as a result of mental disorder or developmental disability, he or she is unable to understand the nature of the criminal proceedings or to assist counsel in the conduct of a defense in a rational manner. (Ibid.; see also Dusky v. United States (1960) 362 U.S. 402 [4 L.Ed.2d 824, 80 S.Ct. 788].) A defendant’s trial while incompetent violates state law and federal due process guarantees. (Pate v. Robinson (1966) 383 U.S. 375, 385 [15 L.Ed.2d 815, 86 S.Ct. 836]; People v. Pennington (1967) 66 Cal.2d 508, 516-517 [58 Cal.Rptr. 374, 426 P.2d 942].) A defendant is presumed competent unless the contrary is proven by a preponderance of the evidence. (§ 1369, subd. (f); People v. Medina, supra, 51 Cal.3d at pp. 881-886; see Medina v. California (1992) 505 U.S. 437, 448-451 [120 L.Ed.2d 353, 112 S.Ct. 2572] [placing burden on defendant to prove incompetence does not violate due process].) On appeal, the reviewing court determines whether substantial evidence, viewed in the light most favorable to the verdict, supports the finding on competency. (People v. Marshall (1997) 15 Cal.4th 1, 31 [61 Cal.Rptr.2d 84, 931 P.2d 262].) Evidence is substantial if it is reasonable, credible and of solid value. (Ibid.) The jury heard this evidence during the 1989 competency proceedings: Court-appointed Psychiatrist Roland Levy examined defendant for 45 minutes on March 21, 1989, and concluded he was incompetent. Dr. Levy reported that defendant displayed affect inappropriate to the content of his conversation and spoke of how a computer, apparently connected to the FBI, influenced him and was responsible for the killings, but wandered off that subject and began to talk about such matters as organized crime, government control and working for secret agencies. Dr. Levy suspected defendant might be experiencing auditory hallucinations and concluded he could not distinguish his delusions from reality. Defendant’s delusions had a diffuse quality, while another person with better organized paranoid schizophrenia could present a delusion in such a way as to make it almost believable. Dr. Levy considered and rejected the possibility that defendant was faking mental illness, noting the only deception defendant seemed to be practicing was his overt denial that he was mentally ill. Dr. Levy diagnosed defendant as suffering from chronic schizophrenia with paranoid traits. He observed that defendant was reacting well to the antipsychotic medication Navane at a dosage that would cause a nonpsychotic person to feel slow and unable to think. On July 16, 1989, defendant met with Dr. Levy for 45 minutes; the next day, he refused to meet with him. The defense then called Psychiatrist James Missett, who had examined defendant at the prosecution’s request. Dr. Missett met with defendant for 45 minutes on October 7, 1986, and five hours on October 13, 1986; on July 25, 1989, he observed defendant during a 90-minute court hearing and, on another occasion, for 90 minutes in jail. Dr. Missett diagnosed defendant as having antisocial and borderline personality disorders and sexual sadism; he ruled out a diagnosis of schizophrenia, characterizing defendant’s symptoms as inconsistent with a diagnosis of schizophrenia and his delusions as having a “psychosis of the day” quality. Dr. Missett believed defendant was malingering and had fooled other psychiatrists who had arrived at different diagnoses. He concluded defendant obtained gratification from “jerking people around.” The defense also called Psychiatrist George Wilkinson, whom the court had appointed to examine defendant in connection with the competency proceedings. Dr. Wilkinson examined defendant on several occasions, the first of them on May 27, 1987, when he committed involuntarily defendant, who was acutely psychotic, to Chope Hospital after an emergency referral by jail staff. His next examination of defendant, lasting more than 90 minutes, occurred on January 5, 1988, when defendant reported experiencing hallucinations. Dr. Wilkinson felt that defendant, who admitted the truth of his confessions but refused to discuss the facts of his case, was manipulating him. On January 26, 1988, Dr. Wilkinson again examined defendant, finding him competent but recommending an evaluation at Atascadero State Hospital to settle the question of whether he was malingering. (The recommended evaluation did not occur.) After defendant was again committed to Chope Hospital in May 1988, Dr. Wilkinson examined defendant and concluded that, although he had experienced psychotic episodes, he could still cooperate with counsel and was competent to stand trial. On March 1, 1989, after trial counsel reported deterioration in his relationship with defendant, Dr. Wilkinson attempted to interview defendant, who refused for delusional reasons to come out of his jail cell. Then, after a court appearance on July 7, 1989, Dr. Wilkinson saw defendant for some 45 minutes and found him to be psychotic, with disorganized thinking, loose associations, auditory hallucinations and inappropriate affect. Dr. Wilkinson’s two later attempts to see defendant failed when defendant stood in his urinal and refused to come out of his cell. Dr. Wilkinson diagnosed defendant as suffering from paranoid schizophrenia, although his symptoms did not fit all the criteria for that illness. He viewed defendant’s manipulation of psychiatrists as a self-protective mechanism to compensate for feelings of humiliation and low self-esteem. At times, however, defendant would get his attempts to manipulate mixed up with his illness. Dr. Wilkinson noted defendant’s condition had improved when he was taking Navane, consistent with someone who has had a genuine psychotic episode. Dr. Wilkinson agreed with Dr. Levy that defendant lacked the skills to fake a major mental illness completely. He disagreed with Dr. Missett that variability in reported delusions meant the patient was faking; indeed, a lack of variation in such delusions would be more consistent with total faking. Trial Counsel Douglas Gray testified that defendant initially expressed hostility toward him and disclosed such delusional beliefs as that his former attorney had killed a California Highway Patrol officer and received hundreds of thousands of dollars in bribes, from either organized crime or the government, to stop defendant from pleading guilty. At first defendant only wanted to plead guilty, but later he developed a working relationship with Gray. That relationship faltered as defendant’s mental condition deteriorated in the fall of 1988. Defendant appeared almost emaciated and had not bathed for some time, and by January 1989 his statements were incomprehensible and disconnected and he began to refuse to see Gray. When Gray initiated competency proceedings, defendant reacted negatively, said he would not take psychotropic medication and did not want to go to Atascadero State Hospital, and declared he was not and had never been mentally ill. On the first day of competency proceedings, defendant wore his jail clothes in compliance with counsel’s tactical decision. On the second day, defendant angrily said he did not want to wear jail clothes but wanted instead to wear street clothes in order to get a fair trial. Even after being removed to a holding cell, he screamed at his attorneys. Finally defendant agreed to behave in court in exchange for the attorneys’ agreement to permit him to wear street clothes in court. Defendant told Gray he did not want to testify in the competency proceedings because he was embarrassed and shy about answering questions about the psychiatrists, who, he maintained, had lied. He indicated that if he could confine his testimony to the homicides there would be no problem. The attorneys would not guarantee that, so he did not testify. Attorney Thomas Nolan testified as an expert in what is needed for a client to assist rationally in a capital case. Nolan testified that if a person is uncommunicative due to mental illness, or wants to plead guilty because a computer was responsible for the crime and refuses to consider an insanity defense, or prefers communicating with the district attorney over his own counsel, or sends letters to sheriff’s deputies without telling his counsel, he is not rationally assisting counsel and is preventing counsel from fulfilling his or her role. The prosecution presented the testimony of several deputy sheriffs, who described their interactions with defendant at court and in jail. On May 6, 1988, Deputy Sheriff Debra Rosengart was assigned to transport defendant to Chope Hospital. From an area where she could not be seen, Rosengart observed defendant stop talking to himself when she left his sight; when Rosengart reappeared to defendant, she saw him resume talking to himself, only to stop when she told him to do so. While transporting defendant in a van, Rosengart turned on the radio to drown out his ramblings; he stopped talking and began to sing along. While walking into the hospital, defendant was silent; after Rosengart told him to go along to his evaluation, he resumed talking to himself. Sheriff’s Sergeant Robert Prevot was assigned to the jail in 1987 and 1988 and there had contact with defendant, who was generally very quiet and read and slept a lot. On February 16, 1989, Deputy Sheriff Martin Douglas transported defendant to court. Defendant was quiet until he was called into court, when he started babbling. As soon as defendant left court after his appearance, Douglas noticed he stopped babbling. Deputy Sheriff William Southward, who sometimes worked in the jail, testified he never saw unusual conduct by defendant. Once Dr. Levy came to visit defendant at his cell; when defendant asserted he did not know the doctor and Southward described him, defendant refused to meet with him. Deputy Sheriff John Quinlan testified that while he was assigned to work in the jail, he never heard defendant make unusual statements. On three to five occasions Quinlan saw defendant engage in “bizarre” behavior, including refusing to see family members, refusing to come out for recreation, and smearing a substance onto his cell window. Deputy Sheriff David Barrett testified he had known defendant for two years as a result of his jail assignment and had a great deal of contact with him over eight to 12 months. Barrett and defendant conversed about bicycling, movies and television. When the conversation touched on his crimes, defendant spoke about computers. Defendant told Barrett he had smeared shampoo onto his cell window in order to scare away predatory inmates by making them think he was crazy. Joan Davies was trained to work with persons with dyslexia and spent hundreds of hours, over a four-year period, helping defendant with his reading skills before her son John disappeared. Mrs. Davies attended the trial. She testified that when the prosecutor, during his opening statement, incorrectly asserted that defendant had lived with the Davies family, defendant turned in his seat, made eye contact with Davies and her husband, and shook his head “no.” Sacramento County Sheriff’s Department Investigator Robert Bell first made contact with defendant in 1984, during the murder investigations; after defendant was arrested, he occasionally contacted Bell. In February 1988, defendant complained to Bell that his attorneys were trying to present a “sham” psychiatric defense in which defendant did not want to participate. Defendant told Bell he committed the murders because he had received radar transmissions from a large antenna in Russia instructing him to kill. Bell told defendant he was disappointed because defendant had earlier confessed and now seemed to be shirking responsibility. Defendant became quiet and eventually said he wanted to talk about something else. Belmont Police Officer Joseph Farmer testified to the contents of defendant’s 1986 confessions, including the details of the Davies and Turner homicides and the assault on Steve Murphy. Defendant contends this evidence was insufficient to support the jury’s competency finding. In particular, he urges that Dr. Missett’s opinion—that he was competent and malingering—was contrary to facts of record and to uncontested medical and scientific facts. Here, defendant asserts, the only substantial evidence was that he was psychotic, no evidence to the contrary was presented, and no evidence showed that even if he was psychotic he nevertheless was competent to stand trial. We disagree. The opinions of the various experts stood in conflict, and in assessing their testimony the jury was entitled to consider that Dr. Missett had more than five hours of contact with defendant in 1986 against which to evaluate his behavior during the 1989 competency proceedings. The jury also heard that Dr. Wilkinson, in two 1988 reports, had found defendant competent and changed his mind after a March 1, 1989, contact that lasted only 15 minutes. Although Dr. Wilkinson saw defendant again on July 7, 1989, for 45 minutes and found him to be psychotic, he felt less than total (i.e., only 75 to 80 percent) certainty that defendant was incompetent. Dr. Levy had briefer contact with defendant than had Dr. Missett (two 45-minute evaluations), from which the jury could infer that Dr. Missett’s opinion was entitled to greater weight. Although defendant argues his behavior fit the classic model of incompetency in that—like truly psychotic people—he sometimes insisted he was not mentally ill and refused to see the psychiatrists who were in a position to assist him in avoiding his criminal trial through a finding of incompetency, the jury was entitled to consider that, during his first competency trial the year before, defendant had heard expert witnesses describe the behavior of genuinely psychotic persons and the ways malingerers go wrong in feigning mental illness. The jury, moreover, was aware that defendant had the opportunity to observe the behavior of psychotic persons while in the locked psychiatric ward at Chope Hospital, and heard Dr. Wilkinson testify that defendant was cunning and manipulative, and derived gratification from frustrating psychiatrists. Defendant cites evidence that he responded favorably to antipsychotic medications, which only a psychotic person can tolerate without becoming sleepy and clouded in thinking; on Navane, defendant related better to people, was less hostile, had less trouble controlling his impulses, and apparently experienced none of the sedation that would be expected in a nonpsychotic person taking the drug. Defendant also criticizes as scientifically invalid Dr. Missett’s reliance on a definition of schizophrenia as involving fixed, firm delusions (and his resulting opinion that because the reported details of defendant’s delusional material varied from time to time, he must be making up the material as he went and therefore was malingering), noting that other experts acknowledged the existence of types of schizophrenia involving fluctuating or variable delusions. But whether defendant was in fact mentally ill and, if so, his precise diagnosis was not determinative of his competency. Dr. Wilkinson testified one can be both paranoid schizophrenic and competent to stand trial. The testimony of Dr. Missett and the lay witnesses describing defendant’s behavior, taken together (see People v. Marshall, supra, 15 Cal.4th at pp. 31-32), provides substantial evidence to support the jury’s finding that defendant understood the nature of the criminal proceedings and had the ability to assist his counsel in a rational manner (§ 1367, subd. (a)). c. Asserted flaws in CALJIC No. 4.10 and reliability of competency verdict As requested by the parties, the trial court instructed the competency phase jury with CALJIC No. 4.10 as follows: “In this proceeding you must decide whether the defendant is mentally competent to be tried for a criminal offense. [f] This is not a criminal proceeding and the innocence or guilt of the defendant of the criminal charge against him is not involved nor is the question of his legal insanity at the time of the commission of the offense involved, [f] Although on some subjects his mind may be deranged or unsound, a person charged with a criminal offense is deemed mentally competent to be tried for the crime charged against him, if: [f] One, he is capable of understanding the nature and purpose of the proceedings against him; two, he comprehends his own status and condition in reference to such proceedings; and three, he is able to assist his attorney in conducting his own defense in a rational manner. [][] The defendant is presumed to be mentally competent. The effect of this presumption is to place upon the defendant the burden of proving by a preponderance of the evidence that he is mentally incompetent as a result of a mental disorder.” Defendant contends this instruction was flawed in several respects. The Attorney General urges that trial counsel, by joining in the prosecutor’s request for the instruction, invited any error and that defendant therefore is barred from raising these contentions on appeal. On the record before us, we cannot say that trial counsel both “ ‘intentionally caused the trial court to err’ ” and did so for “ ‘tactical reasons.’ ” (People v. Coffman and Marlow (2004) 34 Cal.4th 1, 49 [17 Cal.Rptr.3d 710, 96 P.3d 30].) Reviewing the merits of defendant’s argument, we find no error. First, defendant argues the instruction improperly permitted the jury to find him competent if it believed he had a mental disorder but could be made able to assist his counsel in a rational manner if he were administered antipsychotic medications. Defendant observes that the evidence—including his own statements and the fact that, once returned to jail after each of his involuntary commitments, he stopped taking the medication he had been compelled to take while in the hospital—indicated he would not voluntarily ingest them. Such a predicate to a competency finding, he contends, would violate both the federal Constitution and state law. He argues that because it cannot be discerned from the general verdict of competency whether the jury based its finding on permissible or impermissible considerations, the judgment cannot stand. Defendant acknowledges that a recent decision of the United States Supreme Court permits, under certain circumstances, the involuntary administration of antipsychotic medications in order to make a criminal defendant competent to stand trial. (Sell v. United States (2003) 539 U.S. 166 [156 L.Ed.2d 197, 123 S.Ct. 2174] (Sell).) To be consistent with the federal Constitution’s protection of a defendant’s liberty interest, Sell holds such medication must be medically appropriate, substantially unlikely to have side effects that may undermine the fairness of the trial, and, taking account of less intrusive alternatives, necessary to significantly further important governmental trial-related interests, and the trial court must so find. (Sell, supra, 539 U.S. at pp. 180-181, 186; Riggins v. Nevada (1992) 504 U.S. 127, 135-136 [118 L.Ed.2d 479, 112 S.Ct. 1810] [the Sixth and Fourteenth Amendment rights of a fair trial and due process demand that, when a criminal defendant files a motion to terminate the administration of antipsychotic medication during trial, the state must establish the need for, and medical appropriateness of, the medication]; Washington v. Harper (1990) 494 U.S. 210, 222-227 [108 L.Ed.2d 178, 110 S.Ct. 1028] [state law that provided convicted prisoners with administrative rather than judicial review of involuntary medication orders adequately protected constitutional liberty interests].) Defendant contends that, because the jury might have believed he would be competent only if medicated, because the trial court here did not make the findings required by Sell, and because the record indicates he was not voluntarily taking medication at the time of the 1989 competency trial, and indeed shows that he refused to take prescribed psychotropic medication after his release from each of his several involuntary commitments to Chope Hospital, the jury’s finding of competency is invalid. As the Attorney General observes, because this case does not involve an effort to forcibly medicate defendant, the Sell findings were not required. For the same reason, the jury’s finding of competency here is not invalidated by decisions such as Thor v. Superior Court (1993) 5 Cal.4th 725, 732 [21 Cal.Rptr.2d 357, 855 P.2d 375], recognizing