Opinion

Gilbert Tewksbury was convicted by a jury of-first degree murder (Pen. Code, § 187) and two counts of first degree robbery (Pen. Code, § 211). He contends on appeal from the ensuing judgment that his convictions were unlawful in that they are supported only by the uncorroborated testimony of two witnesses who were as a matter of law accomplices. 1 He contends alternatively that the juiy was improperly instructed that he had the burden of proving by a preponderance of the evidence that one of such witnesses was an accomplice. We conclude that neither of the foregoing nor other contentions can be sustained and we affirm the judgment.

In the early morning hours of December 24, 1970, two masked men armed with handguns robbed two employees of the El Torito Restaurant in Encino. The robbery occurred in a parking lot near the restaurant shortly before it closed. During the robbery one of the victims was fatally shot. The surviving victim was not able to identify his assailants.

Defendant’s connection with the robberies and murder was established only by the testimony of two witnesses, Mary Pedraza and Sheila Twiford. Defendant lived in the home of Mary and her husband Mike *957 Pedraza at the time of the charged crimes. Sheila Twiford was then defendant’s girlfriend. On the day prior to the crimes she was employed as a cocktail waitress at the El Torito Restaurant. She left work around 9 that evening and went to the Pedraza residence to visit defendant. The Pedrazas were not then at home. As she talked to defendant about her job she mentioned how busy the restaurant had been. Defendant asked how much money she thought the restaurant had taken in and when she told him about $8,000 or $10,000 he replied that “he wanted to rob it.” Defendant telephoned his friend Richard Bribes, told Bribes of his plans and asked him to join them. Defendant told Bribes to bring dark clothing, dark nylons, handkerchiefs, and tape.

Sometime between 10 and 11 p.m. Mary Pedraza had returned home. She was followed shortly thereafter by her husband Mike. Both Pedrazas were under the influence of drugs. It is not clear whether they arrived home before defendant had telephoned Bribes, but in any event Bribes was not present when they arrived. As Maiy was busying herself about the house she overheard defendant and Sheila as they conversed but Mary paid no attention to the substance of the conversation. At Sheila’s request Mary telephoned the El Torito Restaurant and was informed that the kitchen closed at 12 o’clock.

After Bribes arrived at the Pedraza residence he discussed plans with defendant and Sheila in a back room. The Pedrazas were in a different part of the house and did not participate in the discussion. Sheila used pencil and paper supplied by Mary to draw a diagram of the restaurant. She showed the diagram to defendant, Bribes, and Mary. According to Mary no one seemed to be able to understand the diagram, so she suggested to Sheila that she accompany defendant and Bribes to the restaurant so they might personally observe it. Sheila, however, stated she did not wish to do so.

Around midnight defendant and Bribes left for the restaurant in Bribes’ car. Before leaving they told the others to meet them at a predetermined place near the restaurant in another car. Mary was at first reluctant to go but her husband urged her to join them “for the ride.” Finally she agreed to go, partly because she wanted to get out of, the house and partly because she thought her husband was too intoxicated to drive the second vehicle.

With Sheila giving directions Mary drove to the place where defendant and Sheila had planned to meet. After waiting for 20 to 25 minutes *958 defendant and Bribes approached in Bribes’ car. Defendant stated that something had gone wrong, that Bribes had shot someone and that they would have to leave quickly. Defendant then left Bribes’ car to join Sheila, forcing the Pedrazas to move to Bribes’ car. On the way back to the Pedraza residence defendant related to Sheila what had occurred. He stated that while engaged in tying two restaurant employees outside the restaurant Bribes’ gun had accidentally fired and that they fled without receipts from the restaurant. They had, however, taken a total of $480 from the two employees.

The two cars returned to the Pedraza residence where the money was divided. Each of the five parties received $100 except Sheila who received only $80. However, the two Pedrazas each gave $20 to Bribes .and Sheila gave her entire $80 to defendant.

Defendant urged two defenses at trial. One was an alibi, and by the other defendant sought to establish that both Sheila and Maiy, the only witnesses who connected defendant with the crimes, were accomplices whose testimony had to be corroborated pursuant to section 1111. 2 There is no question that Sheila was an accomplice and no challenge is made to the trial court’s ruling to that effect. Sheila was initially charged with the murder and robberies and was held to answer at the preliminary hearing. In exchange for her testimony, however, the prosecutor agreed to allow her to plead guilty to a single charge of second degree robbery. The question of Mary’s status as an accomplice is crucial, for if she is an accomplice then her testimony cannot be used to corroborate Sheila’s testimony as the required corroboration must come from a source other than another accomplice. There is no other independent source of corroboration in the instant case.

Initially Mary was charged with the murder and robberies and was held to answer following a preliminary hearing. However no further proceedings had been undertaken against her at the time of defendant’s trial. She at first asserted her right not to incriminate herself and refused to answer any questions as a witness at defendant’s trial. She .was thereafter granted immunity but she again refused to answer all but a few background questions for fear of incriminating her husband Mike. (See Evid. Code, § 970.) Although proceedings against Mike had been *959 dismissed and he was thereafter granted immunity, Mary nevertheless remained a very reluctant witness. She was once adjudged in contempt for refusing to testify but the court vacated its ruling when she finally indicated that she would cooperate. Nevertheless her testimony remained less than complete. She testified that she was “loaded” on “reds” on the night in question and neither was fully aware of nor remembered what had happened. 3 Each time Mary returned to the stand her memory improved and her testimony became increasingly detailed. Eventually she was able to corroborate Sheila’s testimony that defendant was one of the two robbers. She also remembered receiving a share of the stolen money from either defendant or Sheila when they returned to her house after the robbery. Moreover she recanted somewhat her earlier testimony that she did not have knowledge of the intended robbery and that she did not actually realize that a robbery was to take place until Sheila told her about it while waiting in the car.

*960 “An accomplice is .. . defined as one who is liable to prosecution for the identical offense charged against the defendant . . . .” (§ 1111.) This definition includes all principals in a criminal act (i.e., “[a]ll persons concerned in the commission of a crime” (§ 31)) but does not include accessories (i.e., “[e]very person who, after a felony has been committed, harbors, conceals or aids a principal in such felony” (§ 32)). Whether a person is an accomplice is a question of fact for the jury unless there is no dispute as to either the facts or the inferences to be drawn therefrom. (See People v. Hoover (1974) 12 Cal.3d 875, 880 [117 Cal.Rptr. 672, 528 P.2d 760].) The fact that “the witness was prosecuted for the same offense as defendant does not alone establish her to be an accomplice [as a matter of law].” (People v. Gordon (1973) 10 Cal.3d 460, 467 [110 Cal.Rptr. 906, 516 P.2d 298].) Thus Mary Pedraza is not necessarily an accomplice merely because she was held to answer for the same crimes as defendants and then granted immunity. Nor did she necessarily become an accomplice if it be deemed that she aided in the commission of the crimes. Criminal liability as a principal attaches to those who aid in the commission of a crime only if they also share in the criminal intent (§ 20; see also Pinell v. Superior Court (1965) 232 Cal.App.2d 284, 287 [42 Cal.Rptr. 676]) or, in the language of section 31, abet the crime. 4 Mary was thus an accomplice only if at the time she acted she had “guilty knowledge and intent with regard to the commission of the crime.” (People v. Duncan (1960) 53 Cal.2d 803, 816 [3 Cal.Rptr. 351, 350 P.2d 103].) Although it is undisputed that Mary aided appellant by calling the restaurant, by supplying Sheila with pencil and paper, and by driving some of the principals to a point of rendezvous in the vicinity of the crimes, such actions do not confer upon her accomplice status unless she also acted with the requisite guilty intent. She need not have actually had the specific intent to commit a robbery however; the intent requirement is satisfied if Mary, prior to its commission, realized that a robbery was being planned and that she was facilitating its commission. (People v. Terry (1970) 2 Cal.3d 362, 401 [85 Cal.Rptr. 409, 466 P.2d 961]; People v. Germany (1974) 42 Cal.App.3d 414, 420 [116 Cal.Rptr. 841].)

Defendant argues that Mary must have realized as a matter of law that she was aiding the commission of a robbery and must therefore have possessed the requisite guilty knowledge. Although the jury could have *961 reached that conclusion, the evidence, especially Mary’s own testimony, was subject to conflicting inferences and would also have supported a finding that she did not have guilty knowledge. 5

While Mary did at one point admit that she eventually realized defendant and Bribes were planning a robbery while at her home, she testified she was unaware of the details. In particular she did not know when the robbery was to take place, nor did she draw any connection between the activities of defendant and Bribes and her own actions including her subsequent departure from her house with her husband and Sheila. In fact she indicated a sense of relief when the two men left *962 the house before her, feeling that her involvement with them had ended at that point. 6

Thus Mary’s testimony generally showed her to have been at least as reluctant a participant in the robbery as she was a witness. While her testimony did contain many inconsistencies, it was not wholly incapable of belief and we must on appeal resolve all inferences and inconsistencies in favor of the jury’s implied finding that she was not an accomplice. So viewed her testimony does reasonably support the finding that she acted without guilty knowledge prior to the actual perpetration of the robbery and that she did not ever realize ■ that she was aiding in its commission until after it had been accomplished and she heard Sheila talking about it while waiting in the car for defendant and Bribes. 7 The court thus did not err in failing to instruct that Mary was an accomplice as a matter of law.

Defendant’s alternative complaint of trial court error is grounded upon the court’s instruction that defendant had the burden of proof to show by a preponderance of the evidence that Mary was an accomplice. 8 Defendant contends that the court should have instructed sua sponte (see People v. Gordon, supra, 10 Cal.3d 460) that the prosecution had the burden of proving that Mary was not an accomplice, either by proof beyond a reasonable doubt or at least by a preponderance of the evidence.

Defendant is initially confronted with the express provisions of the Evidence Code that a “party [i.e., defendant] claiming that a person [i.e., *963 Mary] is guilty of crime or wrongdoing has the burden of proof on that issue.” (Evid. Code, § 520; see also Evid. Code, § 500.) Consistent with this allocation of the burden of proof it is uniformly held that the defense initially bears the burden of producing evidence to raise the accomplice issue (Evid. Code, § 550) and that in the absence of any such proof the witness is treated as not being an accomplice. (7 Wigmore on Evidence (3d ed.) § 2060; People v. Johnson (1971) 18 Cal.App.3d 458, 463-464 [95 Cal.Rptr. 316, 96 Cal.Rptr. 695]; see also People v. Hoover, supra, 12 Cal.3d 875, 882-883; People v. Waller (1939) 14 Cal.2d 693, 702-703 [96 P.2d 344].)

The placement of the burden of proof of accomplice status on the defendant claiming such status on the part of a witness does not, however, resolve the more difficult question by what standard the burden is to be discharged, for the burden of proof could require that the defendant “raise a reasonable doubt concerning the existence or nonexistence of a fact or that he establish the existence or nonexistence of a fact by a preponderance of the evidence, by clear and convincing proof, or by proof beyond a reasonable doubt.” (Evid. Code, § 115; see also Evid. Code, § 502.) The general rule is that “[e]xcept as otherwise provided by law, the burden of proof requires proof by a preponderance of the evidence.” (Evid. Code, § 115.)

An important exception exists, however, in criminal cases as to the proof of all elements of the crime or crimes charged. Thus when there is placed upon an accused the burden of interjecting a factual contention which, if established would tend to overcome or negate proof of any element of the crime charged as otherwise established by the People, the accused need only raise a reasonable doubt as to the existence or nonexistence of the fact in issue. (Evid. Code, § 501; Pen. Code §§ 1096, 1105; see People v. Hardy (1948) 33 Cal.2d 52, 63-66 [198 P.2d 865] [burden on defendant to go forward with the evidence but he need only raise a reasonable doubt as to his claimed unconsciousness]; People v. Costello (1943) 21 Cal.2d 760, 765-766 [135 P.2d 164] [when a defendant presents alibi evidence he need only create a reasonable doubt that he could have committed the crime]; see also People v. Montalvo (1971) 4 Cal.3d 328, 333-334, fn. 3 [93 Cal.Rptr. 581, 482 P.2d 205, 49 A.L.R.3d 518]; People v. Agnew (1940) 16 Cal.2d 655, 665-667 [107 P.2d 601] [when defendant claimed lawfulness of arrest as defense to a charge of false imprisonment he need only create a reasonable doubt whether the arrest was unlawful]; People v. Roe (1922) 189 Cal. 548, 560-561 [209 P. 560] [when defendant asserts defense of the person of another as a *964 defense to a charge of murder, she need only create a reasonable doubt that she killed with criminal intent]; People v. Bushton (1889) 80 Cal. 160, 164 [22 P. 127, 549] [although defendant has burden of proving mitigation in a homicide case (see § 1105), he need only create a reasonable doubt that the greater crime was committed]; People v. Marshall (1881) 59 Cal. 386, 388-389 [a defendant who asserts an intent to marry as a defense to a charge of taking a female for purposes of prostitution need only create a reasonable doubt that he took her for purposes of prostitution].) 9 Indeed, the United States Supreme Court has held it to be constitutionally impermissible to place on a defendant a burden heavier than that of raising a reasonable doubt as to circumstances of mitigation in a homicide prosecution. (Mullaney v. Wilbur (1975) 421 U.S. 684, 703-704 [44 L.Ed.2d 508, 522-523, 95 S.Ct. 1881]; see also People v. Thomas (1945) 25 Cal.2d 880, 896-897 [156 P.2d 7]; People v. Wells (1938) 10 Cal.2d 610, 619-623 [76 P.2d 493].)

There are, however, other instances of defenses asserted by an accused which raise factual issues collateral to the question of the accused’s guilt or innocence and do not bear directly on any link in the chain of proof of any element of the crime. Among such defenses are those which raise no challenge to the sufficiency of the prosecution’s proof of any element of the crime charged but for reasons of public policy insulate the accused notwithstanding the question of his guilt. (See Witkin, Cal. Criminal Procedure, § 343, pp. 335-336.) Entrapment is one of such public policy defenses (see People v. Benford (1959) 53 Cal.2d 1, 8-9 [345 P.2d 928]) and the collateral question whether an accused was entrapped must be proved by him by a preponderance of the evidence. (People v. Moran (1970) 1 Cal.3d 755, 760-761 [83 Cal.Rptr. 411, 463 P.2d 763].) In still other contexts factual issues which are collateral are raised by the assertion of defensive matter which challenges the reliability of particular incriminating evidence. 10 Again the factual issue raised, that is, the proof *965 of the fact upon which the challenge to reliability can be asserted, is collateral to the question of the accused’s guilt or innocence. Proof of such collateral factual issue, as in the case of the proof of the factual issue on which the public policy .defense rests, is not one which must be established in the direct chain of proof of the accused’s guilt. 11 There is thus no constitutional compulsion that such collateral fact be proved beyond a reasonable doubt, nor does the presumption of the accused’s innocence aid in the resolution of such fact. 12

In those instances wherein an accused bears the burden of establishing factual matters which are preliminary to an attack on the reliability of incriminating evidence, he has not been deemed to have satisfied that burden merély by raising a reasonable doubt that the *966 preliminary fact does or does not exist. The most common of such attacks are challenges to hearsay evidence because of its unreliability. The proponent of such a statement must overcome its questionable reliability by proof of collateral factual matters which bring the statement within an exception to the hearsay rule, thereby demonstrating its reliability. (See Evid. Code, § 405; Lane v. Greyhound Lines (1945) 26 Cal.2d 575, 582 [160 P.2d 21]; 5 Wigmore on Evidence, §§ 1362, 1420, 1422.) The court, which finds the existence or nonexistence of the preliminary fact (Evid. Code, § 405, subd. (a)), is not expressly required to so find by proof beyond a reasonable doubt and, when not “otherwise provided by law, the burden of proof requires proof by a preponderance of the evidence.” (Evid. Code, § 115.) Although the law otherwise provides that an accused must be proved guilty beyond a reasonable doubt (§ 1096) the law does not require such a degree of proof offactual matters not in the chain ofproof of an accused’s guilt of the crime charged. (People v. Haston, supra, 69 Cal.2d 233, 253.) It thus follows that in the determination of a preliminary fact which conditions the admissibility of a hearsay statement to be considered on the merits by the trier of fact, the court’s determination is to be made on proof by a preponderance of the evidence. 13

*967 As in the case of a challenge to evidence on hearsay grounds an attack on the credibility of a witness is also a challenge to the reliability of his testimony. When that attack is based on the conviction of a prior felony the proof of such conviction does not constitute proof of a fact within the chain of proof of the accused’s guilt of the crime charged, and there is no requirement that the prior conviction be established by proof beyond a reasonable doubt.

Accomplice testimony is suspect because, like hearsay, it too may be unreliable. “[Experience has shown that the evidence of an accomplice should be viewed with care, caution and suspicion because it comes from a tainted source and is often given in the hope or expectation of leniency or immunity.” (People v. Wallin (1948) 32 Cal.2d 803, 808 [197 P.2d 734]; see also People v. McRae (1947) 31 Cal.2d 184, 186 [187 P.2d 741]; People v. Dail (1943) 22 Cal.2d 642, 654 [140 P.2d 828]; People v. Coffey (1911) 161 Cal. 433, 438 [119 P. 901]; 7 Wigmore on Evidence (3d ed.) § 2057, pp. 322-325.) In addition to being derived from a suspect source accomplice testimony is frequently cloaked with a plausibility which may interfere with the jury’s ability to evaluate its credibility. “ ‘[A]n accomplice is not merely a witness with a possible motive to tell lies about an innocent accused but is such a witness peculiarly equipped, by reason of his inside knowledge of the crime, to convince the unwary that his lies are the truth.’ ” (Heydon, The Corroboration of Accomplices (Eng. ed. 1973) Crim.L.Rev. 264, 266; see also Note, 54 Colum.L.Rev. 219, 234.)

At common law the fact that a witness was an accomplice resulted only in an instruction that his testimony was to be viewed with care, caution, and suspicion unless corroborated in any material matter by independent evidence. (People v. Coffey, supra, 161 Cal. 433, 438; see also 7 Wigmore on Evidence (3d ed.) § 2056, pp. 312-322, and cases cited therein at fn. 10.) The limitation based on the common law distrust of accomplices as now embodied in section 1111 is much harsher than the common law limitation. Juries are now compelled rather than cautioned to view an accomplice’s testimony with distrust, for while his testimony is always admissible and in some respects competent to establish certain facts (see People v. McRae, supra, 31 Cal.2d 184, 187 [probable cause to hold defendant to answer at preliminary hearing]), such testimony has been legislatively determined never to be sufficiently trustworthy to establish guilt beyond a reasonable doubt unless corroborated. Whatever the use of the testimony, however, the limitation on that use is imposed because the uncorroborated testimony of an accomplice is deemed to be unreliable.

*968 The degree of proof by which an accused must establish that a witness is an accomplice is the same as in other instances wherein he has the burden of establishing a collateral fact which conditions a challenge to the reliability of incriminating evidence. As in other such instances he cannot satisfy that burden by merely raising a reasonable doubt that the collateral fact does or does not exist. If he is to prevail he must do so by proof by a preponderance of the evidence, the next lighter burden imposed on a party who has the burden of proof. 14 (Evid. Code, § 502.) As the trial court so instructed the jury in the instant case there was no error.

Our conclusion as to the defense’s burden of proof of accomplice status, when such status is urged by him, is also supported by an independent rationale. When it is urged by an accused that a witness is an accomplice there are two means by which the People may nevertheless vest the witness’ testimony with reliability. One is to overcome the accused’s proof that the witness is an accomplice. The other is to produce corroboration. The People may satisfy this latter requirement by proof of *969 factual matters which fall far short of establishing corroboration beyond a reasonable doubt. Although the evidence offered in corroboration must connect the accused with the commission of the crime charged, it “may be slight and entitled to little consideration when standing alone.” (People v. Wade (1959) 53 Cal.2d 322, 329 [1 Cal.Rptr. 683, 348 P.2d 116]; see also People v. Perry (1972) 7 Cal.3d 756, 769 [103 Cal.Rptr. 161, 499 P.2d 129].) Certainly if the trier of fact can give full weight to an accomplice’s testimony if that testimony is corroborated on meager proof, it likewise should be able to give full weight to that testimony if it appears that the witness is not an accomplice on proof which falls short of the standard of beyond a reasonable doubt.

Defendant also complains of the seizure of a .22 caliber handgun during a search of the Pedraza residence six days after the homicide at a time when defendant was no longer residing there. The homicide victim was killed by a bullet fired from a .22 caliber weapon, but the bullet was damaged to such an extent that a ballistics expert was unable to develop information essential to an identification of the gun from which the bullet had been fired. Sheila described during her testimony two guns which prior to the homicide had been in defendant’s possession and had been taken from the Pedraza home, one each by defendant and Bribes when they left for the El Torito Restaurant on the evening of the homicide. When defendant and Sheila were arrested at a motel six days after the homicide, the People seized from defendant’s immediate possession two guns which, Sheila first testified, were the same two guns she had seen in defendant’s possession prior to the homicide. However, when the gun seized during the search of the Pedraza home was exhibited to Sheila she also recognized it as one of the two guns she had seen in defendant’s possession. 15 The surviving victim of the robberies testified that one of his assailants was armed with a gun which was similar to the .22 caliber handgun seized from the Pedraza home and that the fatal shot was fired from such a gun. He could not, however, further identify the gun.

Defendant contends that the .22 caliber handgun taken from the Pedraza residence was seized in violation of constitutional prohibitions because the gun was not described in a warrant pursuant to which the People had searched the Pedraza home. Generally police officers may seize any contraband discovered in the proper execution of a search *970 warrant although the particular item is not described in the warrant. (See Skelton v. Superior Court (1969) 1 Cal.3d 144, 157 [81 Cal.Rptr. 613, 460 P.2d 485].) The warrant in the instant case was obtained on the basis that there were narcotics present in the Pedraza home, and the handgun was discovered during a search which was reasonably limited to the discovery of concealed narcotics. It appears, however, that an officer charged with executing the warrant had been informed prior to the time application therefor had been made of the possible presence of a gun used in the robberies and homicide at the El Torito Restaurant, and that he anticipated the discovery and seizure of the gun during the narcotics search. 16

Defendant relies on Coolidge v. New Hampshire (1971) 403 U.S. 443 [29 L.Ed.2d 564, 91 S.Ct. 2022] for the proposition that the seizure of an evidentiary item which the state knew or suspected would be disclosed during a purported search pursuant to a warrant for other contraband, is constitutionally impermissible. We do not deem it necessary to venture a solution to the puzzle of Coolidge 17 and conclude for the reasons which *971 follow that the seizure of the gun and its receipt in evidence, even if contrary to Coolidge, does not require that the judgment be reversed.

Although the substantiality of the evidence connecting defendant to the crimes must depend on the testimony of an accomplice, that testimony compellingly demonstrates defendant’s guilt. Sheila testified persuasively under aggressive cross-examination that she was present when defendant first suggested the crime and that defendant planned it *972 with others at the Pedraza home; that he armed and equipped himself and Bribes; instructed others at the Pedraza home to meet him and Bribes at a designated place after the planned robbery; that he left the Pedraza home for the purpose of committing the robbeiy; that he met with the others at the designated place and told them that he and Bribes had robbed two employees of the restaurant but had inadvertently shot one of the victims; and that he returned to the Pedraza home and divided the loot. All other testimony adduced at the trial, including the testimony of Mary Pedraza and the surviving victim of the robberies and testimony of the corpus delicti and the time, place and manner of the commission thereof, is consistent with Sheila’s account.

The controversial gun, however, is of little significance in the overall evidence as the part it played in the commission of the crime, if any, was never established. Defendant’s counsel aptly described the insignificance of such gun evidence in urging that it could not be deemed as corroborative of Sheila’s testimony for purposes of section 1111. He stated that the gun was “many orders of magnitude removed from linking [defendant] to the matter. The gun was found at a different location [than that where defendant was arrested]. There is no identification that the gun was in fact the gun that was used .. ..”

We conclude that the evidence of defendant’s guilt is overwhelming even without those inferences of guilt, if any, which may be drawn from the fact that a gun similar to that.with which defendant or Bribes was armed on the evening of the homicide was later seized at the Pedraza residence. Assuming without deciding that the court erred in not suppressing the gun, we hold that such error was harmless beyond a reasonable doubt. (Chapman v. California (1967) 386 U.S. 18, 24 [17 L.Ed.2d 705, 710, 87 S.Ct. 824, 24 A.L.R.3d 1065].)

Defendant raises numerous other contentions, none of which merit discussion.

The judgment is affirmed.

McComb, J., Tobriner, J., Mosk, J., Sullivan, J., Clark, J. and Richardson, J., concurred.