¶1I agree with the majority that the guilt verdicts and special circumstance finding must be affirmed.
¶2We issued an order to show cause in this case and thus established that defendant had made out a prima facie case that he had been inadequately represented at the penalty trial. (In re Hochberg (1970) 2 Cal.3d 870, 875, fn. 4 [87 Cal.Rptr. 681, 471 P.2d 1].) Defendant alleged that counsel had failed to contact any members of his family or to investigate background evidence adequately. He asserted that there was some evidence of his psychological defects available from his school records and records of his experiences in group therapy. In addition, he alleged that his mother and sister would have testified about his traumatic childhood with alcoholic, combative parents. He alleged that counsel were incompetent in failing to present any case in mitigation.
¶3Defendant was represented by two attorneys. Respondent sought to establish that their representation had been adequate by supplying declarations of counsel explaining their failure to put on any evidence at the penalty phase. One attorney declared that defendant had asked that no member of his family testify in mitigation, and that counsel decided not to overrule this request because of defendant’s gang membership. “It was tactically felt that if the Pandora’s Box of his violent background was opened for exploration as a sympathy measure for the jury to peruse that it could have been savagely explored by the prosecution and would have done more harm than good.”
¶4The second attorney declared that he did not have time to review his trial file or prepare a more comprehensive declaration because he was engaged in another capital case. However, he did remember that defendant had instructed counsel not to call any witnesses, and particularly not defendant’s mother, in the penalty phase. He said that both counsel were aware of defendant’s rap sheet and gang involvement and thought that they “posed an ominous double-edged sword if introduced at the penalty phase.” He maintained that “it was a joint tactical decision between defendant/appellant and counsel to avoid bringing in material on behalf of the defendant/appellant which would open the door—wide open—for the prosecution to introduce evidence in rebuttal, even without notice.” He again emphasized that defendant had told them not to call family members dur*125ing the penalty phase, and admitted that they never talked to defendant’s mother about his background because defendant did not want family members to testify. He said that he “cannot comment on defendant/appellant’s early environmental development” and again “is unable to comment on defendant/appellant’s school years.”
¶5Defendant’s traverse contains a declaration denying that he instructed his attorneys not to call his family or any other witnesses at either the guilt or penalty phase of trial. He realleges the allegations contained in his petition.
¶6The majority opinion finds no ineffective assistance because counsel had a tactical reason for failing to put on evidence in mitigation: “Here, counsel made a clear tactical choice not to introduce evidence at the penalty phase. This decision was based on their knowledge of defendant’s background and their fear that otherwise inadmissible bad character evidence could be used by the prosecution in rebuttal. (See People v. Boyd (1985) 38 Cal.3d 762 [215 Cal.Rptr. 1, 700 P.2d 782].)” (Maj. opn., ante, at p. 121, italics in original.)
¶7Investigation of the facts and the law is one of counsel’s primary duties. (People v. Pope (1979) 23 Cal.3d 412, 424-425 [152 Cal.Rptr. 732, 590 P.2d 859, 2 A.L.R.4th 1]; People v. Ibarra (1963) 60 Cal.2d 460, 464 [34 Cal.Rptr. 863, 386 P.2d 487].) Counsel may reject a defense for tactical reasons, but such a tactical choice is not a competent one unless counsel has conducted an adequate investigation. (People v. Ledesma (1987) 43 Cal.3d 171, 215 [233 Cal.Rptr. 404, 729 P.2d 839]; People v. Frierson (1979) 25 Cal.3d 142, 166 [158 Cal.Rptr. 281, 599 P.2d 587]; In re Saunders (1970) 2 Cal.3d 1033, 1042, 1048-1049 [88 Cal.Rptr. 633, 472 P.2d 921]; People v. Bess (1984) 153 Cal.App.3d 1053, 1060 [200 Cal.Rptr. 773]; see also In re Hall (1981) 30 Cal.3d 408, 426-427 [179 Cal.Rptr. 223, 637 P.2d 690].) We have recently acknowledged the great importance of investigation of defendant’s background in preparation for the penalty phase of a capital trial, holding that counsel must present mitigating evidence which counsel considers of value even over the defendant’s objection. (People v. Deere (1985) 41 Cal.3d 353, 364-368 [222 Cal.Rptr. 13, 710 P.2d 925].)
¶8The majority cites recent decisions from the United States Supreme Court in Burger v. Kemp (1987) 483 U.S. _ [97 L.Ed.2d 638, 107 S.Ct. 3114] and Strickland v. Washington (1983) 466 U.S. 668 [80 L.Ed.2d 674, 104 S.Ct. 2052] to show that counsel may make a competent tactical decision to limit investigation for the penalty phase of trial. But in neither case did counsel completely forego investigation of defendant’s background. Moreover, in both cases, there was an evidentiary hearing held to determine whether the decision to limit investigation was in fact competent. In Burger *126v. Kemp, the high court’s decision turned on the record produced at this evidentiary hearing. Unfortunately, the majority here denies the defendant the benefit of such an evidentiary hearing.
¶9From the record available, it appears that counsel here carried out no investigation of the available evidence in mitigation before making the tactical decision not to present any evidence at the penalty phase. I question whether a total failure to investigate the case in mitigation for the purpose of the penalty trial can ever be competent representation. Even if it could be competent in light of a particular trial tactic, here, one of the two reasons upon which counsel rested their total failure to investigate was compliance with their client’s request that no family members be called. But this reason for failure to investigate is not a competent one. (See People v. Deere, supra,41 Cal.3d 353.)
¶10The majority relies upon an appallingly arrogant declaration to show that counsel made a competent tactical choice neither to investigate nor to present evidence in mitigation. There, counsel says that he cannot comment on defendant’s allegations because he has been too busy in another capital trial to review his files in this case. Neither counsel bothers to respond to defendant’s allegation that there was available evidence of his early mental problems in school records. Counsel do not deny that they did not investigate: how did they judge whether to put on a case in mitigation until they knew what it was? Under these disquieting circumstances, we simply need to know more before we can be satisfied that counsel made a competent tactical choice.
¶11Even counsel’s tactical reason for failing to put on a case in mitigation is unconvincing. Their declarations show an unexamined feeling that background evidence might backfire, rather than an analysis of a point of evidence. We should not accept as tactically valid any decision to forego even investigating a case in mitigation just because defendant has a poor record. Boyddoes not mean that whenever defendant puts on any background evidence, the prosecution can put in defendant’s whole history in rebuttal. (See People v. Boyd (1985) 38 Cal.3d 762, 776 [215 Cal.Rptr. 1, 700 P.2d 782].) If counsel had put in evidence that defendant’s early childhood was chaotic and painful, or that he had psychological problems as a child, how would evidence of defendant’s gang membership or rap sheet have been relevant in rebuttal? And anyway, how would counsel know whether the case in mitigation would open up harmful rebuttal unless they knew what was available in mitigation? As far as we can tell, these attorneys did not know what was available.
¶12Of course defendant has the burden of proving the facts on which he relies in his claim for relief on habeas corpus. (In re Saunders, supra, 2 *127Cal.3d 1033, 1047-1048.) But once the reviewing court issues its order to show cause and the issues are joined by traverse and return, if there are factual issues remaining which cannot be resolved on the pleadings, we normally order an evidentiary hearing. (See, e.g., In re Lawler (1979) 23 Cal.3d 190, 194 [151 Cal.Rptr. 833, 588 P.2d 1257]; In re Hochberg, supra,2 Cal.3d 870, 873-874, fn. 2.) Given the serious factual questions remaining in this case, I cannot agree with the majority that this case can be resolved without such a hearing.
¶13Mosk, J., concurred.
¶14A petition for a rehearing was denied January 7, 1988, and the opinion was modified to read as printed above.
¶15The special circumstance finding must be affirmed because the jury returned a special finding that the killing was wilful, deliberate, and premeditated. This finding, of course, established intent to kill. (See People v. Burgener (1986) 41 Cal.3d 505, 536-537 [224 Cal.Rptr. 112, 714 P.2d 1251].)