Full opinion text
Opinion ARABIAN,J. —Defendant Donald Jay Beardslee was charged under the 1978 death penalty law with the first degree murders of Paula (Patty) Geddling and Stacy Benjamin under two special circumstances. A jury found defendant guilty of committing both murders with premeditation and deliberation (Pen. Code, §§ 187, 189; all section references are to that code unless otherwise indicated) and further determined that each murder was committed under two special circumstances: concurrent conviction of multiple murders (§ 190.2, subd. (a)(3)) and intentional killing for the purpose of preventing the victim from testifying as a witness to a separate crime (§ 190.2, subd. (a)(10)). Defendant also was found to have personally used a firearm in the murder of Patty Geddling (§§ 1203.06, subd. (a)(1), 12022.5) and a knife in the murder of Stacy Benjamin (§ 12022, subd. (b)). A penalty trial was then held before a different jury, which determined that defendant should suffer the death penalty for the murder of Patty Geddling and life imprisonment without possibility of parole for the murder of Stacy Benjamin. (See §§ 190.3, 190.4, subd. (a).) The trial court denied defendant’s motions to strike the special circumstances and to modify the penalty, and entered a judgment of death. (§ 190.4, subd. (e).) Defendant’s appeal is automatic. (§ 1239, subd. (b).) We conclude that one of the multiple-murder and both witness-killing special circumstances must be set aside, and that the judgment otherwise be affirmed. Guilt Phase Evidence Patty Geddling, age 23, and Stacy Benjamin, age 19, were murdered at separate locations on April 25, 1981. At the time of their deaths, they were living together as close friends. Stacy sold drugs and had a reputation for “ripping people off.” Patty on occasion also sold drugs. Defendant, age 37, was then living in his studio apartment in Redwood City with Ricki Soria, whom he had met two months earlier while she was hitchhiking. Defendant wanted to help Soria stop using drugs and to separate her from Ed Geddling (Patty’s estranged husband) and Frank Rutherford, who were drug dealers. Rutherford had a reputation for carrying guns and collecting drug debts, and had bragged that he would never go to jail because he or his brothers would take care of any witnesses. He was prosecuted separately for the present killings, and defendant’s transcribed testimony at Rutherford’s preliminary hearing comprised a principal part of the prosecution’s guilt phase evidence against defendant. On April 23, Soria told defendant that Stacy had cheated William Forrester in a drug deal. The next afternoon, defendant agreed with Soria and Rutherford to help Forrester get back at Stacy and Patty that evening in defendant’s apartment. Forrester came to the apartment, and defendant picked up Rutherford, who had a shotgun. The four discussed plans for trapping the victims. Rutherford cut a wire and twisted the ends around shotgun shells. At defendant’s request, Soria went out and bought tape for gagging the victims. It was agreed that when the victims arrived, Soria would sit on the sofa, defendant would open the door, and Rutherford and Forrester would hide. Defendant testified he expected Rutherford and Forrester to “rough [the victims] up a little bit,” tie and gag them, take their money and drugs, and leave. The victims arrived around 6:30 p.m. As defendant opened the door and they approached Soria, defendant heard the shotgun fire. He then saw that Rutherford was holding the gun and that Patty was wounded in the left shoulder. Defendant took her into the bathroom and tried to stop her bleeding. Both victims’ hands and feet were tied. Rutherford told Patty they would take her to the hospital, and repeated this statement in Stacy’s presence while winking at defendant. Between 9 and 10 p.m., defendant and Forrester left and brought back Rutherford’s car. After a discussion with Rutherford about taking the victims somewhere in their own van, defendant believed the victims would be killed. But when Rutherford handed him some shotgun shells, defendant said, “I’m not going to do this.” Forrester said, “Well, I guess I’m going to do it.” Patty was loaded into the victims’ van, which was driven away by Forrester with defendant as a passenger. Soria followed in defendant’s car. Rutherford stayed behind with Stacy. Forrester drove south on Highway 1 and onto Bean Hollow Road, where they stopped. Patty got out of the van and began pleading for her life. Defendant loaded the gun for Forrester, who shot Patty twice. Defendant reloaded and also fired at her twice. Leaving Patty’s dead body in a ditch beside the road, they departed, Soria and Forrester in the van and defendant in his own car. When the van ran out of gas, the three wiped off their fingerprints and abandoned it. Defendant and Soria then dropped off Forrester and returned to defendant’s apartment. While there, they received a telephone call from Rutherford, asking them to join him at the nearby apartment of his girlfriend, Dixie Davis. Arriving at Davis’s apartment between 3 and 3:30 a.m., they found Stacy watching television. Out of Stacy’s hearing, defendant told Rutherford that Forrester had “chickened out” and defendant had to finish the job. Rutherford said defendant should have killed Forrester; defendant replied that Soria had refused to give him more shells for that purpose. Then, in Stacy’s presence, defendant and Rutherford had a conversation implying that Patty was in the hospital. About 5 a.m., defendant, Rutherford, Soria, and Stacy left in defendant’s car. They stopped at a service station where Stacy collected money she was owed for drugs, stopped in Pacifica where Soria obtained cocaine, and made two more stops to consume the cocaine before crossing the Golden Gate Bridge. They stopped to see Rutherford’s brother in Sebastopol, where defendant heard Rutherford obtain advice from the brother on where to “drop off” Stacy. Defendant understood this to refer to killing Stacy and leaving her body somewhere. They headed north on Highway 101 and turned onto a winding side road. Defendant was driving. Rutherford told Stacy they were going to Lakeport to obtain drugs. They stopped at a turnout. Stacy was upset, but Rutherford coaxed her out of the car, and all four walked up the hill. Soria and Rutherford went back to the car, and Stacy asked if defendant was supposed to strangle her then. He said, “No.” When Soria returned with Rutherford, she told defendant in a low voice that Rutherford had “fixed up” the wire. Defendant and Soria walked further, where they could not see Rutherford and Stacy. Defendant heard some commotion, however, and Soria urged him to go help Rutherford. Defendant found Rutherford sitting on Stacy, strangling her with his left hand. A broken wire lay under her neck. Rutherford called Stacy a “die hard bitch.” Defendant saw Stacy give him a pleading look, and he punched her in the left temple, attempting unsuccessfully to knock her out. Defendant then held one end of a wire wrapped around Stacy’s throat while Rutherford pulled on the other end. Rutherford took both ends of the wire, pulled it tight, and twisted it. The two men dragged Stacy to a more secluded area. Defendant asked for Rutherford’s knife and used it to slit Stacy’s throat twice. After she was dead, defendant, at Rutherford’s suggestion, pulled down her pants to make it appear that she had been assaulted sexually. Late that afternoon, Rutherford, Soria, and defendant returned to the Davis apartment. Early that morning, Patty’s body was found by joggers. A shoe repair claim ticket, recovered from her clothing, bore defendant’s telephone number. Accordingly, Detective Sergeant Robert Morse of the San Mateo County Sheriff’s Office called on defendant, who agreed to come to the sheriff’s office to give a statement. Morse began the interview by talking about the difference between a witness and a suspect, and then asked defendant if he were involved in the case. Defendant replied: “Well, Frank [Rutherford] shot her but I guess I’m involved because I shot her in the head twice myself. I was afraid.” Defendant was advised of his Miranda rights and gave a detailed, taped statement about both killings. From defendant’s directions, officers found Stacy’s body near the Hopland Grade Road in Lake County, as well as numerous items of physical evidence at scattered locations in San Mateo County. A transcription of defendant’s statement, as well as the tape itself, became a prosecution exhibit at the trial. Defendant testified in his own behalf. His trial testimony, his prior testimony at the Rutherford preliminary hearing, and his taped statement were essentially consistent, except for differences in his versions of the fatal blows. At trial and in prior testimony at the preliminary hearing, defendant said that after Forrester fired twice at Patty, defendant felt her pulse and decided she was dead. Nonetheless, he retrieved the gun from Forrester and fired twice in the direction of her head but did not think he hit her. He did this out of fear that Rutherford would have him killed if he were only a witness and not a participant in Patty’s death. In his taped statement, however, defendant said he thought Patty was still alive after the shots by Forrester, and shot directly at her to keep her from suffering. The condition of Patty’s remains seemed more consistent with the taped statement. When her body was found, about one-third of her head was missing. According to the doctor who performed an autopsy, there were multiple shotgun wounds. One, in her left shoulder, preceded the others by several hours. A wound in her chest and another in her back, which occurred about the same time, would not have been immediately fatal; she could have survived for several minutes. The head wound, however, was inflicted by a shot or shots fired at extremely close range and caused instant death. Similarly, defendant testified at trial and at the preliminary hearing that when he slit Stacy’s throat, he concluded she was already dead because there was only one exhalation of breath, and the blood from her jugular vein dribbled out rather than spurting. He conceded he had helped Rutherford pull the wire around her throat, but he considered himself only a “minor” participant in her death. In his taped statement, however, he said that when he asked Rutherford for the knife, Stacy was still alive and trying to gasp, and that when he slit her throat he was trying to “make it quick.” The pathologist who examined Stacy’s body testified that the knife wound cut her left jugular vein and exposed her air passage but did not cut the carotid artery. From the presence of blood in her lungs, he concluded that she must have been still alive when her throat was cut. He said the blood loss was relatively slow, “not the kind of blood loss you get from an artery.” Defendant testified as follows: He agreed at the outset to help Rutherford because he did not want to stand up to him. He felt shaky about Rutherford’s bringing the shotgun to his apartment, but thought it would only be used as a scare tactic. He suggested Soria procure the tape for gagging the victims because he wanted to minimize any noise emanating from the apartment. But later in the evening, after Rutherford had used the shotgun on Patty, defendant became involved in the plans to dispose of the women out of fear for his life. He participated in both killings because he was afraid that Rutherford would have him killed if he were only a witness rather than a participant. I. Requested Instruction on Honest Belief in Imminent Peril as Negating Malice Defendant relied on the defense that he participated in the homicides because he feared that if he did not do so, Rutherford would kill him or have him killed. Section 26 lists among those not capable of committing crimes “[p]ersons (unless the crime be punishable with death) who committed the act or made the omission charged under threats or menaces sufficient to show that they had reasonable cause to and did believe their lives would be endangered if they refused.” (§ 26, subd. Six, italics added.) The jury was instructed that a person is not guilty of a crime if he acts under threats or menaces that cause him reasonably to fear that his life would be in immediate danger if he did not do the otherwise criminal act. (See CALJIC No. 4.40; all references to CALJIC are to the fourth edition 1979, unless otherwise indicated.) But in accordance with the statutory exception, the jury was also instructed that such threats are not a defense “[wjhere a person commits first degree murder with a special circumstance.” (See CALJIC No. 4.41.) In addition to the foregoing instructions on threats as an absolute defense, the court gave two other instructions that broadly authorized the jury to consider the effect of threats on the mental states requisite to murder. One of these instructions authorized the jury to consider “evidence show[ing] the existence of threats, menaces or compulsion that played a part in inducing the unlawful killing of a human being ... for such bearing as it may have on the question of whether the murder was of the first or second degree.” The other instruction stated as follows: “If you find from the evidence that at the time the alleged crime was committed the defendant honestly held a belief that his own life was in danger, you must consider what effect, if any, this belief had on the defendant and whether he formed any of the specific mental states that are essential elements of murder, [fl] Thus if you find he had an honestly held belief that his life was in peril and as a result did not maturely and meaningfully premeditate, deliberate and reflect on the gravity of his contemplated act or form an intent to kill, you cannot find him guilty of a willful, deliberate and premeditated murder of the first degree, [fl] Also, if you find the defendant did not form the mental state constituting express malice, you cannot find him guilty of either the first or second degree. [([] In the event that you find the defendant is guilty of one or more murders in the first degree, you may still consider the operation of threats, menaces or compulsion, if any, with regard to your finding on the special circumstances.” (Italics added.) Notwithstanding these instructions, defendant claims the trial court erred in refusing his request for an instruction that threats causing him to believe honestly that “his own life was in imminent peril” would negate malice aforethought and reduce his crime to voluntary manslaughter. The court declined not only this request but also all other requests for instructions on manslaughter. Defendant now contends that the court’s action deprived him of the defense that even if he intended to kill, his honest but unreasonable belief in the necessity of self-defense negated the element of malice. He relies on People v. Flannel (1979) 25 Cal.3d 668, 674 [160 Cal.Rptr. 84, 603 P.2d 1], in which we held that “[a]n honest but unreasonable belief that it is necessary to defend oneself from imminent peril to life or great bodily injury negates malice aforethought, the mental element necessary for murder, so that the chargeable offense is reduced to manslaughter.” (Italics omitted.) We need not decide what relevance, if any, Flannel has to this case, for any error in refusing to give the requested instruction was harmless. As noted, the court instructed the jury to consider what effect an honest belief that defendant’s life was in danger may have had on the formation of any of the specific intent requirements for first degree murder and the special circumstance allegations. The instructions “did not entirely remove the question of the defendant’s mental state from the jury’s consideration” (People v. Croy (1985) 41 Cal.3d 1, 13 [221 Cal.Rptr. 592, 710 P.2d 392]), or the question of his honest belief that his life was in danger. So instructed, the jury rejected a second degree murder verdict in favor of first degree. In Croy, the trial court instructed the jury that an aider and abettor must have knowledge of the perpetrator’s unlawful purpose, but erroneously did not instruct that he must also share the guilty intent of the perpetrator. Although intent is different from knowledge, we held that it may be possible to find that the error “could not possibly have affected the verdict—i.e., that no reasonable trier of fact, having actually found the requisite knowledge, could at the same time have concluded that the defendant did not act for the purpose of facilitating or encouraging the crime. In those cases the judgment could be affirmed.” (41 Cal.3d at p. 14.) This rationale applies here. No reasonable trier of fact, having rejected a second degree murder verdict in favor of first degree after being instructed to consider any honest belief that defendant’s life was in danger, would have returned a manslaughter verdict because of the same factor under the instructions the court did not give. Any error was thus harmless. II. Effect of Instructions Upon Defense of Honest but Unreasonable Mistake Defendant contends that an erroneous jury instruction deprived him of the defense that he did not intend to kill the victims because he honestly but mistakenly believed they were dead when he inflicted the fatal blows. He concedes that the instruction authorized the defense if the honest mistake was found to be reasonable but complains that the instruction improperly deprived him of the defense if the mistake was found to be honest but unreasonable. Defendant requested, and the court orally gave, the following jury instruction: “An act committed or an admission [sic: omission] made under an ignorance or mistake of fact which disproves any criminal intent is not a crime. Thus a person is not guilty of a crime if he commits an act or omits to act under an honest or reasonable belief in the existence of certain facts and circumstances which, if true, would make such act or omission lawful.” (Italics added.) During jury deliberations, however, the jury requested and was given a written copy of the instructions in which the phrase “honest or reasonable,” italicized in the foregoing quotation, appeared as “honest and reasonable” (italics added). Defendant now contends that the written form of the instruction, which conformed to CALJIC No. 4.35, erroneously precluded the jury from giving exculpatory effect to a mistake on his part that was honest even if not reasonable. We need not decide what effect, if any, an honest but unreasonable belief that the victims were dead when defendant inflicted the fatal blows would have had upon his criminal liability for their deaths. Whatever the merits such a mistake-of-fact theory may have in the abstract, it has no application to this case. A court is required to instruct on a theory of the case only if it is supported by substantial evidence. (People v. Flannel, supra, 25 Cal. 3d at pp. 684-685.) No such evidence exists even under defendant’s version of the facts. Defendant played an active role both in the acts which actually killed the victims and in the acts which, under his theory, he believed killed them. When a person commits an act based on a mistake of fact, his guilt or innocence is determined as if the facts were as he perceived them. (People v. Rivera (1984) 157 Cal.App.3d 736, 743 [203 Cal.Rptr. 842].) Here, if the facts were as defendant supposedly perceived them, he still actively participated in both murders. Even if the jury had found that defendant thought Patty was already dead when he shot her, and that he thought Stacy was dead when he slit her throat, his participation in both crimes was not limited to the shooting or the throat slitting. With regard to Patty, defendant acknowledged that he was aware that she was going to be killed while they were still in his apartment. He drove with Forrester and Patty to a remote area. When Patty got out of the van and began pleading for her life, defendant loaded the gun for Forrester, who shot her twice. As to Stacy, before slitting her throat, defendant held one end of the wire around her throat while Rutherford pulled on the other end. A belief, even if genuine, that different acts by defendant helped kill the victims than the acts that actually did so would not make defendant’s actions lawful. Such a belief would not absolve defendant of the murders. The court was therefore under no duty to instruct on the defense. There was no error. III. Instructions on Principals, Including Aiders and Abettors The jury was instructed that persons who are legally regarded as “principals in the crime . . . and equally guilty thereof, include [1] those who directly and actively commit the act constituting the crime or [2] those who with knowledge of the unlawful purpose of the person who directly and actively commits the crime intentionally aid and abet in its commission, or [3] those who, whether present or not at the commission of the crime, advise and encourage its commission.” (See CALJIC No. 3.00.) Defendant contends that this instruction permitted the jury to return a verdict of first degree murder without finding that he acted with the requisite malice, premeditation, and deliberation. Because the instruction was requested by defendant’s trial counsel, as well as by the prosecution, the Attorney General contends that any claimed defects in it were waived. There appears no conceivable tactical purpose, however, for defense counsel’s requesting an instruction that would erroneously lessen the prosecutorial burden of proving malice, premeditation, or deliberation. Claims of instructional error are reviewable when such error could only have resulted from counsel’s neglect or mistake in requesting the instruction (§ 1259; People v. Barraza (1979) 23 Cal. 3d 675, 683 [153 Cal.Rptr. 459, 591 P.2d 947]) even though defendant would be barred from challenging an instruction that his counsel requested for a deliberate tactical purpose (People v. Avalos (1984) 37 Cal.3d 216, 228-229 [207 Cal.Rptr. 549, 689 P.2d 121]). (See People v. Hernandez (1988) 47 Cal.3d 315, 353 [253 Cal.Rptr. 199, 763 P.2d 1289]; People v. Graham (1969) 71 Cal.2d 303, 319 [78 Cal.Rptr. 217, 455 P.2d 153]; cf. People v. Marshall (1990) 50 Cal.3d 907, 932 [269 Cal.Rptr. 269, 790 P.2d 676] [the requirement of a deliberate tactical choice is limited to situations in which the court is under an obligation to instruct sua sponte in a manner other than it did].) Accordingly, we examine defendant’s present claim on its merits. Defendant contends that under the instruction, if the jury determined that one or more persons other than himself, such as Rutherford, Forrester, or Soria, planned either of the killings, but that defendant was the one who inflicted the fatal wound, i.e., “directly and actively commit[ted] the act constituting the crime” (CALJIC No. 3.00), the jury could find defendant guilty of first degree murder whatever his mental state when he acted. Any such misleading effect of CALJIC No. 3.00 was precluded, however, by the instruction “not to single out any certain sentence or any individual point or instruction and ignore the others,” but instead “to consider all the instructions as a whole and ... to regard each in the light of all the others.” (See CALJIC No. 1.01; People v. Chavez (1985) 39 Cal.3d 823, 830 [218 Cal.Rptr. 49, 705 P.2d 372].). The jury was instructed that murder “perpetrated by any kind of willful, deliberate and premeditated killing with express malice aforethought is murder of the first degree.” (See CALJIC No. 8.20.) Moreover, “[t]o constitute a deliberate and premeditated killing, the slayer must weigh and consider the question of killing and the reasons for and against such a choice and, having in mind the consequences, he decides to and does kill.” {Ibid., italics added.) From these and other instructions, a reasonable juror would understand that one who becomes a principal to the crime of deliberate and premeditated first degree murder by “directly and actively commit[ting] the act constituting the crime” (CALJIC No. 3.00) must have personally premeditated and deliberated with malice aforethought. We need not consider a “tortuous analysis” of the instructions that no reasonable juror would undertake. (People v. Warren (1988) 45 Cal.3d 471, 488 [247 Cal.Rptr. 172, 754 P.2d 218].) Defendant further claims prejudice from CALJIC No. 3.00’s descriptions of two other kinds of principals—those “who, with knowledge of the unlawful purpose of the [active perpetrator] intentionally aid and abet” in the crime’s commission, and those who “advise and encourage its commission.” Those descriptions also, he contends, erroneously exposed him to conviction of first degree murder without a finding of premeditation and deliberation on his part. Each of defendant’s two convictions of first degree murder could have been based on either of two findings: that he was the actual perpetrator or that he was an aider and abettor. Defendant claimed that he did not actually kill either victim because Patty was already dead when he fired the shotgun at her, and Stacy was already dead when he slit her throat. The prosecutor vigorously disputed these claims, but argued that even if the jury were to accept them, it should nonetheless convict defendant of first degree murder as an aider and abettor. In accordance with this argument, the jury was given other instructions, in addition to CALJIC No. 3.00, on aiding and abetting. Defendant contends that these aiding and abetting instructions, even in combination, were deficient in that they authorized his conviction of first degree murder without a finding by the jury that his acts of aiding and abetting were done with premeditation, deliberation, and express malice. No such finding was required. In People v. Beeman (1984) 35 Cal.3d 547 [199 Cal.Rptr. 60, 674 P.2d 1318], we explained that “the aider and abettor must share the specific intent of the perpetrator. By ‘share’ we mean neither that the aider and abettor must be prepared to commit the offense by his or her own act should the perpetrator fail to do so, nor that the aider and abettor must seek to share the fruits of the crime. [Citation.] Rather, an aider and abettor will ‘share’ the perpetrator’s specific intent when he or she knows the full extent of the perpetrator’s criminal purpose and gives aid or encouragement with the intent or purpose of facilitating the perpetrator’s commission of the crime. [Citations.]” (Id. at p. 560.) We further explained in People v. Croy, supra, 41 Cal. 3d 1, that the “aider and abettor need not have intended to encourage or facilitate the particular offense ultimately committed by the perpetrator. His knowledge that an act which is criminal was intended, and his action taken with the intent that the act be encouraged or facilitated, are sufficient to impose liability on him for any reasonably foreseeable offense committed as a consequence by the perpetrator. It is the intent to encourage and bring about conduct that is criminal, not the specific intent that is an element of the target offense, which Beeman holds must be found by the jury. (People v. Beeman, supra, 35 Cal.3d 547, 556.)” (Id. at p. 12, fn. 5.) The jury was given the following instruction based on People v. Yarber (1979) 90 Cal.App.3d 895, 916 [153 Cal.Rptr. 875]: “A person aids and abets the commission of a crime if, with knowledge of the unlawful purpose of the perpetrator of the crime, he intentionally aids, promotes, encourages or instigates by act or advice the commission of such crime.” In Beeman, supra, we criticized that instruction as “sufficiently ambiguous to conceivably permit conviction upon a finding of an intentional act which aids, without necessarily requiring a finding of an intent to encourage or facilitate the criminal offense.” (35 Cal.3d at p. 561.) But any such ambiguity was rendered harmless as to defendant by the instructions underlying the verdicts of guilt of both murders with special circumstances. The jury was told: “If the defendant was not the actual killer, it must be proved beyond a reasonable doubt that he intentionally aided, abetted, counseled, commanded, induced, solicited, requested or assisted the actual killer in the commission of the murder in the first degree before you are permitted to find the alleged special circumstances of that first degree murder to be true as to the defendant.” (See § 190.2, subd. (b).) The latter instruction apprised the jury that if defendant did not actually kill either victim, its verdict of guilt for the murder of that victim with special circumstances must be based on a conclusion that defendant intended to encourage or facilitate the actual killer’s first degree murder of the victim. (People v. Carrera (1989) 49 Cal.3d 291, 310-311 [261 Cal.Rptr. 348, 777 P.2d 121]; People v. Warren, supra, 45 Cal.3d 471, 487-488.) Defendant contends the instructions should have explicitly connected the mental state requisite to aiding and abetting with his defense that he participated in the killings out of fear for his life. Defendant did not request any such instruction but claims that the court should have instructed to that effect on its own motion. The instructions the court actually gave, however, fully covered any valid defense along these lines. As stated earlier, the jury was told that if it should “find from the evidence that at the time the alleged crime was committed the defendant honestly held a belief that his own life was in danger,” it should “consider what effect, if any, this belief had on the defendant and whether he formed any of the specific mental states that are essential elements of murder.” The jury also was instructed that the specific intent with which an act is done may be proved by the surrounding circumstances, which must be not only consistent with the requisite specific intent but irreconcilable with any other rational conclusion. (See CALJIC No. 2.02.) The substance of that instruction was repeated with explicit reference to the mental state required for proof of a special circumstance. (See CALJIC No. 8.83.1.) “[I]n the absence of a request, a trial court must instruct on the general principles of law governing the case, i.e., those principles relevant to the issues raised by the evidence, but need not instruct on specific points developed at trial.” (People v. Flannel, supra, 25 Cal.3d 668, 681 [fn. omitted].) The instructions given the jury provided an ample basis for defendant to argue that his claimed fears for his life were inconsistent with an intent to encourage or facilitate either murder. None of the instructions was inconsistent with that argument, and no additional instructions on the subject were required to be given sua sponte. IV. Absence of Instruction Requiring Unanimous Agreement on Factual Basis for Conviction Defendant contends the trial court should have instructed the jury on its own motion that there was evidence of more than one act on which a conviction of murdering Patty could be based, and that although defendant could be convicted of that murder by proof of any one or more of such acts, all jurors must agree that he committed the same act or acts. (See CALJIC No. 17.01.) (There is no such contention with respect to the murder of Stacy.) The prosecutor argued that defendant should be convicted of the murder of Patty because he fired the fatal shot with intent to kill her, but that even if defendant was not the actual killer because she was already dead, or defendant’s intent to kill was negated by a belief that she was already dead, defendant should be convicted of her murder as an aider and abettor. Defendant claims the jurors should have been told not to convict him of the murder unless they agreed unanimously either that he was the actual killer or that he was an aider and abettor. A requirement of jury unanimity typically applies to acts that could have been charged as separate offenses. (E.g., People v. Diedrich (1982) 31 Cal.3d 263, 280-283 [182 Cal.Rptr. 354, 643 P.2d 971] [multiple acts of bribery; single bribery charge]; People v. Crawford (1982) 131 Cal.App.3d 591 [182 Cal.Rptr. 536] [conviction of possession of firearm by ex-felon; four guns found separately in defendant’s home]; People v. Madden (1981) 116 Cal.App.3d 212 [171 Cal.Rptr. 897] [conviction of forcible oral copulation; evidence of multiple acts].) A jury may convict a defendant of first degree murder, however, without making a unanimous choice of one or more of several theories proposed by the prosecution, e.g., that the murder was deliberate and premeditated or that it was committed in the course of a felony. “[I]t is sufficient that each juror is convinced beyond a reasonable doubt that the defendant is guilty of first degree murder as that offense is defined by the statute.” (People v. Milan (1973) 9 Cal.3d 185, 195 [107 Cal.Rptr. 68, 507 P.2d 956]; accord People v. Guerra (1985) 40 Cal.3d 377, 386 [220 Cal.Rptr. 374, 708 P.2d 1252].) Pursuant to the latter rule, it was held in People v. Forbes (1985) 175 Cal.App.3d 807, 816-817 [221 Cal.Rptr. 275], that a conviction of second degree murder did not require unanimous agreement by the jurors on whether the accused was the actual perpetrator or was an aider and abettor. Defendant urges us to reject the Forbes holding. He argues that the decision whether to convict a defendant as the actual perpetrator or as an aider and abettor is not just a selection of legal theories but is a determination of which acts were committed by the defendant. He relies on People v. Dellinger (1984) 163 Cal.App.3d 284, 300-302 [209 Cal.Rptr. 503], where a first degree murder conviction was reversed on the ground that the trial court should have instructed the jury on its own motion that a conviction required their unanimous agreement on whether the defendant killed the two-year-old victim by giving her cocaine or killed her by inflicting a fatal blow to her head. The Dellinger holding does not apply here. “A unanimity instruction is required only if the jurors could otherwise disagree which act a defendant committed and yet convict him of the crime charged.” (People v. Gonzales (1983) 141 Cal.App.3d 786, 791 [190 Cal.Rptr. 554]; accord People v. Burns (1987) 196 Cal.App.3d 1440, 1458 [242 Cal.Rptr. 573].) “[Where the acts were substantially identical in nature, so that any juror believing one act took place would inexorably believe all acts took place, the instruction is not necessary to the jury’s understanding of the case.” (People v. Crawford, supra, 131 Cal.App.3d 591, 599; see People v. Crandell (1988) 46 Cal.3d 833, 875 [251 Cal.Rptr. 227, 760 P.2d 423] [lead opn. of Kaufman, J.].) Here, there was no prosecutorial contention that defendant committed multiple independent acts, any of which could have led to Patty’s death. Instead, the two theories, that he was the actual perpetrator and that he was an aider and abettor, were based on a single course of conduct. It was undisputed that defendant allowed Patty to be lured to his apartment; helped take her to a deserted roadside with the understanding that she was to be killed; loaded the shotgun for Forrester, who shot her twice; and then shot her himself. Defendant claimed he was not the actual perpetrator because either (1) Patty was in fact killed by Forrester before defendant shot her, or (2) defendant believed she had been killed by Forrester and therefore did not shoot her with intent to kill. But even if some jurors concluded that defendant was the actual perpetrator and others concluded he was only an aider and abettor, there is no possibility that they disagreed on the facts necessary to support the aiding and abetting theory. The jurors who concluded that defendant intentionally killed Patty with premeditation and deliberation necessarily would have believed that if he was not the actual killer, he intentionally encouraged and facilitated the actual killer’s perpetration of first degree murder. Since the jury had to agree unanimously at least on the facts required for conviction as an aider and abettor, and for application of the special circumstance findings to a person who was not the actual killer (§ 190.2, subd. (b)), no further unanimity was required, and the unanimity instruction was not necessary. V. Instruction on Right to Reject Entire Testimony of Witness Who Is Willfully False on Material Point At the request of both parties, the trial court gave the jury the following instruction, based on CALJIC No. 2.21: “A witness willfully false in a material part of his testimony is to be distrusted in others. You may reject the whole testimony of a witness who willfully has testified falsely as to a material point unless from all the evidence you shall believe the probability of truth favors his testimony in other particulars, [if] However, discrepancies in a witness’s testimony or between his testimony and that of others, if there were any, do not necessarily mean that the witness should be discredited. Failure of recollection is a common experience and innocent misrecollection is not uncommon.” The instruction has been approved by this court, as well as by intermediate appellate courts, as a correct statement of the law. (People v. Lang (1989) 49 Cal.3d 991, 1023 [264 Cal.Rptr. 386, 782 P.2d 627], and cases cited therein.) Because the instruction could be applied to the testimony of defendant, he contends it erroneously shifted the burden of proof by allowing the jury to reject his entire testimony unless they believed from all the evidence that his testimony was favored by “the probability of truth.” He claims the instruction thereby increased his burden from that of raising a reasonable doubt of the sufficiency of the prosecution’s evidence to one of affirmatively proving his defenses. He relies on dictum in People v. Lescallett (1981) 123 Cal.App.3d 487, 493 [176 Cal.Rptr. 687], that perhaps the instruction “should be avoided where, under the circumstances of the case, it might appear to be directed principally toward a defendant’s exculpatory testimony.” Although the instruction does appear applicable principally to defendant’s testimony, not all that testimony was exculpatory. Indeed, neither side urged the jury to reject the whole of his testimony, because most of it, together with his testimony in a prior proceeding and his statement to the police introduced by the prosecution, constituted the backbone of the case against him. The controversial parts of his testimony, as to which his credibility was put in question, pertained to his claims of being motivated by a fear of Rutherford and others, and his assertions of the belief that each victim was already dead when he fired the shotgun or used the knife. Thus, while the jury may well have applied the first sentence of the instruction (“A witness false in a material part of his testimony is to be distrusted in others”) to defendant’s testimony, it was highly unlikely to apply the second sentence by “rejecting] the whole testimony of” defendant. Yet it is only the second sentence to which defendant now objects. Even if the jury were to use the second sentence’s criterion for rejecting the whole of defendant’s testimony as a basis for rejecting some part of the testimony, defendant would not have been prejudiced. The instruction at no point requires the jury to reject any testimony; it simply states circumstances under which it may do so. (People v. Johnson (1986) 190 Cal.App.3d 187, 194 [237 Cal.Rptr. 479].) The qualification attacked by defendant as shifting the burden of proof (“unless from all the evidence you shall believe the probability of truth favors his testimony in other particulars”) is merely a statement of the obvious—that the jury should refrain from rejecting the whole of a witness’s testimony if it believes that the probability of truth favors any part of it. “Thus CALJIC No. 2.21 does nothing more than explain to a jury one of the tests they may use in resolving a credibility dispute.” (People v. Blassingill (1988) 199 Cal.App.3d 1413, 1419 [245 Cal.Rptr. 599].) “The weaknesses in [the defendant’s] testimony should not be ignored or given preferential treatment not granted to the testimony of any other witness. As it has been aptly noted in other contexts, a defendant who elects to testify in his own behalf is not entitled to a false aura of veracity. (People v. Beagle (1972) 6 Cal.3d 441, 453 [99 Cal.Rptr. 313, 492 P.2d 1] (impeachment with prior conviction); People v. Zack (1986) 184 Cal.App.3d 409, 415 [229 Cal.Rptr. 317] (impeachment with evidence of prior assaults on decedent).)” (People v. Goodwin (1988) 202 Cal.App.3d 940, 945 [249 Cal.Rptr. 430].) There was no error in giving the instruction in accordance with the parties’ requests. VI. Sufficiency of the Evidence of the Killing-of-witness Special Circumstance Defendant contends that the evidence is insufficient to support the witness-killing special-circumstance findings as to both murders. We agree. The witness-killing special circumstance applies to the intentional killing of a person who witnessed a crime committed prior to, and separate from, the killing for the purpose of preventing the victim from testifying about the crime witnessed. (§ 190.2, subd. (a)(10); People v. Garrison (1989) 47 Cal.3d 746, 792 [254 Cal.Rptr. 257, 765 P.2d 419].) The crime witnessed cannot be deemed “ ‘prior to, and separate from,’ ” the killing when both are part of “ ‘the same continuous criminal transaction.’ ” (People v. Benson (1990) 52 Cal.3d 754, 785 [276 Cal.Rptr. 827, 802 P.2d 330]; People v. Silva (1988) 45 Cal.3d 604, 631 [247 Cal.Rptr. 573, 754 P.2d 1070].) In Benson, the defendant murdered a mother and then, more than a day later, two of her children. We held the murder of the mother and those of the children were “integral parts of a single continuous criminal transaction against the entire family. Accordingly, the witness-killing special-circumstance findings are invalid.” (52 Cal.3d at p. 785.) The same rule applies here. The murders of both Patty and Stacy were part of the same continuous criminal transaction against both victims. We thus set aside both witness-killing special circumstances. Because of this, we need not consider defendant’s contention that the court erroneously instructed the jury on these special circumstances. VII. Refusal to Grant Jury’s Request for Further Instruction Defendant contends he was prejudiced by the trial court’s telling the jury, in response to the jury’s request for an explanation of an instruction, that none of the instructions would be explained. He claims the court erred both in refusing to answer the particular inquiry and in precluding the jury from asking further questions about the instructions. The jury commenced deliberations on the issues of guilt and special circumstances in the early afternoon. Shortly thereafter the jury requested, and was sent, certain exhibits and a copy of the jury instructions. At the end of the day, the jury submitted a note asking, “[Cjould we have defined whether ‘the first degree murder’ constitutes the act as a whole or the defendant’s participation in said act. Please explain in A.M.” The parties now agree that this question referred to the instruction defining deliberate and premeditated murder, CALJIC No. 8.20. After the jury had been excused, the court stated to counsel: “A message was given to the Court by the jury asking for explanation of the jury instructions which, of course, is typical whenever you send instructions into the jury room, [fl] You are advised that the court is not going to explain any instructions. They either get it figured out for themselves or not. [fl] Every time a judge opens his big mouth and tries to explain what an instruction means, he puts his foot in it and the Appellate Court promptly bites it off. [fl] There will be no explanation of any of those jury instructions that went into that jury room, just so you know. That’s what is going to be told to them.” Before excusing the jury, the court told counsel they need not be present when the jury reconvened the next morning. Defendant personally waived his right to be present at that time. When the jury reconvened at 9 a.m., the court told them as follows: “Ladies and gentlemen, also in addition to your request concerning an instruction, there is and can be no explanation of the instructions. You have to just work with them as they are printed. [t[] This is one of the reasons we do not send, ordinarily, instructions into the jury room, because people start . . . picking them apart, ffl] You are going to have to consider the instructions as a whole as one of those instructions will . . . advise you, some of the instructions will apply, some of the instructions will not. [fl] All of those instructions have to be considered as a whole. Do the best you can with them.” The jury then resumed deliberations and at 2 p.m. returned its verdict. Defendant contends the court’s refusal to further explain the instructions violated section 1138, which provides that when the jury “desire to be informed on any point of law arising in the case, . . . the information required must be given . . . .” The court has a primary duty to help the jury understand the legal principles it is asked to apply. (People v. Thompkins (1987) 195 Cal.App.3d 244, 250-251 [240 Cal.Rptr. 516].) This does not mean the court must always elaborate on the standard instructions. Where the original instructions are themselves full and complete, the court has discretion under section 1138 to determine what additional explanations are sufficient to satisfy the jury’s request for information. (People v. Gonzalez (1990) 51 Cal.3d 1179, 1213 [275 CaLRptr. 729, 800 P.2d 1159].) Indeed, comments diverging from the standard are often risky. (E.g., People v. Lee (1979) 92 Cal.App.3d 707, 716 [155 Cal.Rptr. 128].) The trial court was understandably reluctant to strike out on its own. But a court must do more than figuratively throw up its hands and tell the jury it cannot help. It must at least consider how it can best aid the jury. It should decide as to each jury question whether further explanation is desirable, or whether it should merely reiterate the instructions already given. This court did not do The error, however, was harmless. A violation of section 1138 does not warrant reversal unless prejudice is shown. (People v. Kageler (1973) 32 Cal.App.3d 738, 746 [108 Cal.Rptr. 235].) Defendant has not shown prejudice. There was no possible prejudice to defendant from the court’s refusal to answer the jury’s specific question “whether ‘the first degree murder’ constitutes the act as a whole or the defendant’s participation in said act.” The instruction on deliberate and premeditated murder (CALJIC No. 8.20), to which the question referred, described the mental states required for guilt of the “defendant” or the “slayer.” The jury seems to have been wondering how those requirements would apply if “the defendant’s participation in said act [of first degree murder]” was only as an aider and abettor. The aiding and abetting instructions, as already explained, authorized a guilty verdict against one who aided the perpetration of the murder with the intent to facilitate its commission, together with knowledge of the perpetrator’s criminal purpose. If the jury were to attempt to qualify the elements of guilt as an aider and abettor by including additional ingredients from CALJIC No. 8.20, the only likely prejudice would be to the prosecution, not the defense. Thus, defendant cannot have been prejudiced by the court’s refusal to answer the jury’s question. Defendant also contends the court’s response may have discouraged the jury from asking further questions. This, however, is speculation, not proof of prejudice. Nothing in the record suggests the jury was confused as to any other point of law, and certainly not adversly to defendant. As in People v. Kageler, supra, 32 Cal.App.3d at page 746, defendant has not shown prejudice. Penalty Phase Evidence Under stipulated arrangements to which defendant is objecting on appeal, the jury was discharged after returning the verdicts of guilt on the two murders with special circumstances, and another jury was empaneled to determine whether defendant should be sentenced to death or to life imprisonment without possibility of parole in light of the aggravating and mitigating factors set forth in section 190.3. To apprise the new jury of the circumstances surrounding the two murders of which defendant had been found guilty (§ 190.3, factor (a)), the prosecution presented most of the evidence it had introduced before the previous jury. The only other subject on which the prosecution presented evidence was a prior homicide in Missouri. A court reporter read defendant’s testimony at the Rutherford preliminary hearing in which defendant admitted having killed Laura Griffin by choking her with his hands, stabbing her in the throat, and holding her head under water. He said he had been drinking that evening and attributed the killing to his use of alcohol. He further admitted taking Griffin’s purse and burning it in a trash can. The prosecution then called two Missouri police officers to the stand. They told of finding Laura Griffin dead in her apartment on December 28, 1969. Her nude body was lying in the bathtub, which was full of bloody water. The body bore numerous knife wounds as well as marks apparently left by a garroting device around the neck. A pathologist testified she had died from loss of blood. He also identified photographs of the body, which were placed into evidence. Defendant did not testify at the penalty trial, but the defense introduced additional parts of his testimony, as well as some testimony of Soria, which had been presented at the Rutherford preliminary hearing. Much of this testimony dealt with the participation of Rutherford and others in the events leading up to the killings of Patty and Stacy, as well as the fear that defendant claimed as the motivation for his own participation. The testimony also revealed that defendant had spent seven years in a maximum security prison in Missouri. Donald Clooney, a Missouri attorney, testified that defendant came to him in December 1969 and said he had killed a woman and needed help. After ascertaining that the police had no leads to the identity of the killer, Clooney recommended to defendant that he allow Clooney to surrender him to the police with a request that he be placed in a psychiatric ward. He gave defendant the option of going elsewhere for help, in which case his confession to the attorney would be kept confidential. Defendant accepted Clooney’s recommendation. Upon surrendering defendant, Clooney told the police orally and in writing that they were not to question defendant unless Clooney was present. Later Clooney negotiated a plea bargain under which defendant would plead guilty to the second degree murder of Griflin and be sentenced to 18 years’ imprisonment on the condition that he receive psychiatric treatment while incarcerated. The plea was entered and the sentence imposed, but Clooney felt that Missouri failed to live up to the agreement to provide psychotherapy. Defendant was paroled to California in July 1977. The parole conditions included psychiatric outpatient treatment. Unfortunately, after seven weekly sessions, the treatment was discontinued by the psychiatrist. Defendant’s brother and sister testified concerning defendant’s family history. A supervisor at Hewlett-Packard in Palo Alto, where defendant worked as a machinist from February 1979 to April 1981, described defendant as a very good employee who was energetic, showed initiative, and would do more than was required of him. Two of defendant’s instructors at the College of San Mateo described him as a model student and said they had reacted with disbelief upon first hearing that he had been arrested. A woman who had known him since 1979, and frequently dated him, thought he was a “pretty decent person” and that his arrest was out of character. Douglas Gray, the attorney who initially had represented defendant in the present case but was replaced before the guilt trial, testified he had made an arrangement with the district attorney whereby defendant would testify against any of the other participants in the killings and, in return, would be tried last and would be protected from attack while in jail. (In addition to his testimony at Rutherford’s preliminary hearing, defendant testified at the trial of Forrester.) A deputy sheriff assigned to the county jail testified that defendant was a cooperative inmate. Finally, a forensic psychiatrist presented extensive testimony concerning defendant’s personality disorders. VIII. Denial of Investigative Funds Defendant contends the trial court erroneously denied his application for $4,000, under section 987.9, to conduct an Amytal or sodium pentothal interview to enhance defendant’s memory of the crimes. He claims the denial deprived his psychiatric expert of a full opportunity to describe the origins of defendant’s emotional and mental disturbance. However, the only purpose for the proposed procedure mentioned in the application to the trial court was to assist in the cross-examination of Soria and Forrester, who in fact never testified at defendant’s trial. The application did not state any need of an Amytal or sodium pentothal interview for purposes of psychiatric evaluation. Defendant’s failure to state to the trial court his now asserted reason for desiring the testing defeats his claim of error. He had the burden of showing that the investigative services were reasonably necessary by reference to the general lines of inquiry he wished to pursue, being as specific as possible. (Corenevsky v. Superior Court (1984) 36 Cal.3d 307, 320 [204 Cal.Rptr. 165, 682 P.2d 360].) Although a motion for assistance should be viewed with considerable liberality (ibid.), on appeal the trial court’s order is presumed correct. Error must be affirmatively shown. (Id. at p. 321.) Error is not shown on appeal by urging reasons for the investigation not presented to the court. The denial was not an abuse of discretion. (Ibid.) IX. Penalty Phase Jury Selection Issues A. Pretrial Stipulated Arrangement to Select Separate Juries for Guilt and Penalty Phases At the outset of the guilt phase trial, before jury selection began, the court explained to defendant that “the attorneys” had agreed to proceed with trial of the guilt phase before one jury, and, if that jury found guilt and the truth of the special circumstances, the trial of the penalty phase would be before a different jury. The court asked defendant if he understood and consented to that procedure, and he replied that he did. The court also told defendant, “We do believe that it’s in your best interests that we proceed in that particular fashion.” Accordingly, the issues of guilt and special circumstances were tried before a jury selected for only that purpose. After returning its verdict, the jury was discharged, and a new jury was selected for the penalty phase. Defendant now contends that the court had no jurisdiction to make a pretrial order for separate juries and, therefore, once the guilt phase jury was discharged no penalty trial could be held. Section 190.4, subdivision (c), provides: “If the trier of fact which convicted the defendant of a crime for which he may be subject to the death penalty was a jury, the same jury shall consider . . . the truth of any special circumstances which may be alleged, and the penalty to be applied, unless for good cause shown the court discharges that jury in which case a new jury shall be drawn. The court shall state facts in support of the finding of good cause upon the record and cause them to be entered into the minutes.” In People v. Superior Court (Rowland) (1987) 194 Cal.App.3d 11 [239 Cal.Rptr. 257] (Rowland), it was held that under this statute, “a motion for a second jury may be entertained only after the first jury has convicted the defendant of a crime for which he might be subject to the death penalty. There is no room for a court’s pretrial prediction, however enlightened, that a second jury may be needed . . . . [fl] The trial court was without jurisdiction to entertain a pretrial motion for a second jury.” (Id. at p. 13.) Accordingly, the People were granted a pretrial writ of mandate to require the setting aside of an order granting the defendant’s motion for separate juries. Relying on Rowland, defendant contends that the trial court had no jurisdiction, prior to the commencement of his trial, to adopt the stipulated arrangement for separate juries. Thus, he argues, there was no valid basis for discharging the guilt phase jury and impaneling another jury for the penalty phase, and the judgment of death must be reversed. He cites People v. Wojahn (1984) 150 Cal.App.3d 1024 [198 Cal.Rptr. 277]. In Wojahn, the trial court mistakenly discharged a jury that had found the defendant guilty of various crimes but had failed to determine the truth of an alleged prior conviction. Over defense objection, the court instituted a new proceeding in which the prior conviction was found true. On appeal, the court was ordered to amend the judgment by striking the sentence enhancement based on the prior conviction; “double jeopardy considerations” were held to have “prohibited the impanelling of a new jury to try the issue of the prior conviction.” (150 Cal.App.3d at pp. 1032-1035.) By analogy to Wojahn, defendant apparently contends that since, under Rowland supra, 194 Cal.App.3d 11, the trial court lacked jurisdiction to decide, prior to the guilt phase, upon impanelment of a separate jury for the penalty phase of his trial, he is entitled to have the death penalty stricken permanently from the judgment, without any possibility of a new penalty trial. To the contrary, the pretrial arrangement for separate juries was entirely proper. Unlike the orders set aside in Rowland and Wojahn, the arrangement was agreed to, prior to trial, by both the prosecution and the defense, and implemented by order of the court pursuant to its discretion Under section 190.4, subdivision (c). Nothing in the statute forbids impanelment of a new jury for the penalty trial under those circumstances. Section 190.4, subdivision (c), does express a clear legislative mandate for the trial of both guilt and penalty by the same jury (People v. Balderas (1985) 41 Cal.3d 144, 204 [222 Cal.Rptr. 184, 711 P.2d 480]; People v. Thornton (1974) 11 Cal.3d 738, 753 [114 Cal.Rptr. 467, 523 P.2d 267]), but it does not preclude other arrangements on a showing of good cause when approved by the trial court. “The preference for a single jury is by no means a one-sided matter; such a procedure may provide distinct benefits for both the prosecution and the defense. From the prosecution’s point of view, the use of a single jury to determine both guilt and penalty may make it less likely that a juror’s belief as to the inappropriateness of the death penalty will improperly skew the determination of guilt or innocence .... From defendant’s perspective, the use of a single jury may help insure that the ultimate decision-maker in capital cases acts with full recognition of the gravity of its responsibility throughout both phases of the trial and will also guarantee that the penalty phase jury is aware of lingering doubts that may have survived the guilt phase deliberations.” (People v. Fields (1983) 35 Cal.3d 329, 352 [197 Cal.Rptr. 803, 673 P.2d 680] [plur. opn. of Broussard, J.]; see id. at p. 374 [conc. opn. of Kaus, J.]; Buchanan v. Kentucky (1987) 483 U