In this personal restraint petition, petitioner Gary Richardson raises several claims. While we conclude that most of them lack merit, his claim of ineffective assistance of counsel is meritorious. The record establishes that trial counsel previously represented an important witness in the case. This establishes a prima facie case of ineffective assistance of counsel, for the trial court should have been aware of and inquired into this potential conflict of interest. If a potential conflict of interest existed, the trial court's failure to inquire automatically requires reversal even without a showing of prejudice. Remand to the Superior Court is necessary, however, to ascertain the precise nature of trial counsel's representation of the witness and whether a conflict of interest actually existed.
This case is unusual in that Mr. Richardson has completely served his prison sentence. He nonetheless seeks to remove a serious blot from his record and we should reward this quest if his rights have been violated.
Mr. Richardson was convicted of second degree assault on February 21, 1978. The charge arose out of an incident at the Interlude Tavern in Bremerton on October 15, 1977.
After leaving a card game in the back room of the tavern, Mr. Richardson walked into the main room of the tavern for a drink. From this point, the testimony of the various witnesses differs to some extent. It appears, however, that Mr. Richardson became involved in an argument with others in the tavern. The manager, Ray Blackwood, accused Mr. Richardson of sneaking beer into the cardroom and selling it to the other customers, thus depriving the tavern of sales. One of the customers, Bob Wheeler, accused Mr. *671Richardson of romancing Mr. Wheeler's girl friend. The eventual victim, Farrington Kaluna, supported Mr. Wheeler and/or Mr. Blackwood and other customers indicated similar hostility. Mr. Richardson then chose to leave.
Mr. Wheeler, however, pursued his complaints out into the parking lot and a crowd gathered. Mr. Blackwood also came out of the tavern and tossed Mr. Richardson his jacket, which he had left behind. As Mr. Richardson caught the jacket a handgun in the pocket began to slip out and he caught it. The gun was apparently not seen by the surrounding crowd. As the atmosphere grew more heated, Mr. Kaluna, who was unarmed, stepped in and pushed or hit Mr. Richardson. The gun discharged and severely injured Mr. Kaluna.
Mr. Kaluna testified that he pushed Mr. Richardson because he saw Mr. Richardson raise his arm as if to strike Mr. Blackwood. Mr. Richardson denied that he made any move toward Mr. Blackwood. He testified that all he remembered was being hit from the side and feeling a jolt in his hand as the gun went off. He testified that he did not remember cocking the gun or pulling the trigger. 1 This testimony left open both the possibility of self-defense and the possibility of accident and counsel argued both theories to the jury.
As partial support for his self-defense argument, Mr. Richardson claimed that he had previously been threatened by Mr. Blackwood. Mr. Richardson had previously worked *672in the cardroom for Mr. Blackwood and when he was discharged had threatened to tell the police of Mr. Black-wood's "skimming activity", a practice of not fully reporting income from the cardroom on the books. Mr. Blackwood denied any such activity.
To support Mr. Richardson's claim, defense counsel called William Clemmer, a friend of Mr. Richardson who had also worked in the cardroom for Mr. Blackwood. Counsel sought to elicit testimony from Mr. Clemmer about the skimming activity and the resultant conflict between Mr. Blackwood and Mr. Richardson. At this point, the prosecutor suggested that the court should inform Mr. Clemmer of his privilege against self-incrimination and give him an opportunity to consult with an attorney. When the court did this, it became apparent that Mr. Richardson's attorney had previously represented, or was presently representing, Mr. Clemmer as well.
Mr. Sharpe: Did the Court indicate to [Mr. Clemmer] if he wants to consult an attorney, it would give him an opportunity to do that?
The Witness: He is my—
Mr. Denend: I'm not in a position I could advise you in both regards.
The Court: There's a conflict between what he would like, I'm sure for Mr. Richardson and what he would like for you.
Mr. Richardson: I can — I dropped the subpoena on him.
The Court: And what he would like for you, and so you can't talk to Mr. Denend.
The Witness: Well, Mr. Denend is my attorney on—
The Court: I know, Mr. Clemmer, if you'd listen. We have a problem here.
Report of Proceedings, at 483-84. Defense counsel then suggested that Mr. Clemmer simply testify generally about the bad feelings between Mr. Blackwood and Mr. Richardson. The trial court approved this suggestion and made no further inquiry.
The trial continued and the jury returned a verdict of guilty. On appeal, Mr. Richardson's new attorney raised *673only one issue — whether an instruction which set forth more than one alternative method of committing second degree assault denied Mr. Richardson a unanimous jury verdict. The Court of Appeals held that it did not and affirmed Mr. Richardson's conviction. See State v. Richardson, 24 Wn. App. 302, 600 P.2d 696 (1979). Mr. Richardson now seeks to vacate his conviction by way of this personal restraint petition.
I
Initially, Mr. Richardson raises several ancillary claims which are relatively easily disposed of. The first of these is simply a renewal of the claim of instructional error which he raised on direct appeal. Finding no error in the original opinion of the Court of Appeals, and there having been no significant change in the law, we forgo any further analysis and reject this claim of error. We give Mr. Richardson's additional contentions somewhat more consideration, however.
A
Mr. Richardson also argues that his privilege against self-incrimination was violated when a police officer testified that he exercised his right to remain silent. Officer Floyd Bland did testify that Mr. Richardson "said he would not answer" in response to a question about the location of his gun. Report of Proceedings, at 305. Officer Bland also testified later that "I was advised [by Mr. Richardson's attorney] that there was no statement that would be forthcoming from the defendant". Report of Proceedings, at 426. It should be noted, however, that Mr. Richardson failed to make any objections to this testimony.
Assuming arguendo that Mr. Richardson's failure to object does not bar him from raising the issue here (see State v. Modica, 18 Wn. App. 467, 476, 569 P.2d 1161 (1977) (per curiam)), we must concede that this testimony did violate his privilege against self-incrimination. In Doyle v. Ohio, 426 U.S. 610, 49 L. Ed. 2d 91, 96 S. Ct. 2240 (1976), the Supreme Court ruled that a defendant's post-arrest *674silence could not be used even for impeachment purposes. Doyle, at 617-18. We have held the reasoning behind Doyle also bars the use of post-arrest silence in the State's case in chief. See State v. Fricks, 91 Wn.2d 391, 396, 588 P.2d 1328 (1979). Thus, Mr. Richardson is technically correct that admission of the above testimony was error.
Mr. Richardson has not carried his burden of showing prejudice. When constitutional error is raised for the first time in a personal restraint petition, the petitioner must show prejudice by a preponderance of the evidence. In re Hagler, 97 Wn.2d 818, 826, 650 P.2d 1103 (1982). Here, the location of the gun was of little relevance to Mr. Richardson's defenses and his attorney's statement that he did not wish to make a statement "at this time" does not seem especially damaging either. Indeed, the State made absolutely no mention of Mr. Richardson's silence in closing argument. Under these circumstances, we believe the technical error pointed out by Mr. Richardson did no significant harm.
B
Mr. Richardson also argues that the trial court denied him his constitutional right to represent himself. At several points during the trial Mr. Richardson sought to involve himself in argument or in questioning but was told by the trial court to restrain himself. In the last of these instances, the trial court compromised by instructing defense counsel to ask whatever questions Mr. Richardson told him to ask.
While the right of a criminal defendant to represent himself in court is constitutionally protected (Faretta v. California, 422 U.S. 806, 834, 45 L. Ed. 2d 562, 95 S. Ct. 2525 (1975)), it is not absolute. State v. Fritz, 21 Wn. App. 354, 365, 585 P.2d 173, 98 A.L.R.3d 1 (1978). In particular, any assertion of the right must be unequivocal and timely. Fritz, at 360-61. The granting of even an unequivocal demand made during trial rests largely within the informed discretion of the trial court. Fritz, at 361.
In the present case, Mr. Richardson's right of self-rep*675resentation was not violated. In the first place, his demand was not entirely unequivocal. Moreover, it was not made until trial had already begun. Under these circumstances, we believe the solution chosen by the trial court was within its discretion.
II
Mr. Richardson's central claim is that he was denied effective assistance of counsel. He notes several instances of alleged incompetence; however, trial counsel's failure to fully explore Mr. Clemmer's knowledge of Mr. Blackwood's skimming activity and the resultant conflict between Mr. Blackwood and Mr. Richardson is by far the most significant.
A
Such questioning would have strengthened Mr. Richardson's case in two ways. First, it would have given fuller support and significance to Mr. Richardson's fear of Mr. Blackwood. Second, it would have directly impeached Mr. Blackwood, who expressly denied any skimming activity. Mr. Blackwood was a key witness against Mr. Richardson, for he was the only prosecution witness who was not at least somewhat intoxicated.
Despite these considerations, we cannot say that this omission sinks to the level of ineffective assistance of counsel. This court, as well as others, has been rightly hesitant to find assistance of counsel ineffective based solely on questionable trial tactics. "While it is easy in retrospect to find fault with tactics and strategies that failed to gain an acquittal, the failure of what initially appeared to be a valid approach does not render the action of trial counsel reversible error." State v. Renfro, 96 Wn.2d 902, 909, 639 P.2d 737, cert. denied, 103 S. Ct. 94 (1982). See also Annot., Modern Status of Rules and Standards in State Courts as to Adequacy of Defense Counsel's Representation of Criminal Client, 2 A.L.R.4th 27, § 12 (1980) and cases cited therein. Even under more liberal ineffective standards which we have recently considered and left open (see State *676v. Adams, 91 Wn.2d 86, 90-91, 586 P.2d 1168 (1978)), we cannot say, absent more, that trial counsel's performance was so inadequate as to constitute ineffective assistance.
B
There is more in the present case, however. The record demonstrates on its face a potential conflict into which the trial court made absolutely no inquiry.
A special rule applies in such cases. In Holloway v. Arkansas, 435 U.S. 475, 55 L. Ed. 2d 426, 98 S. Ct. 1173 (1978), the Supreme Court held that a trial court's failure, in the face of defense counsel's warning that he had a possible conflict of interest, to either ascertain that the risk of conflict was remote or appoint different counsel per se deprived the defendant of effective assistance of counsel. Holloway, at 484. Moreover, the Court held, error of this nature can never be harmless — prejudice is to be presumed.
In the normal case where a harmless-error rule is applied, the error occurs at trial and its scope is readily identifiable. . . . But in a case of joint representation of conflicting interests the evil — it bears repeating — is in what the advocate finds himself compelled to refrain from doing, not only at trial but also as to possible pretrial plea negotiations and in the sentencing process. It may be possible in some cases to identify from the record the prejudice resulting from an attorney's failure to undertake certain trial tasks, but even with a record of the sentencing hearing available it would be difficult to judge intelligently the impact of a conflict on the attorney's representation of a client. And to assess the impact of a conflict of interests on the attorney's options, tactics, and decisions in plea negotiations would be virtually impossible. Thus, an inquiry into a claim of harmless error here would require, unlike most cases, unguided speculation.
Holloway, at 490-91. See also Sixth Amendment — Conflicts of Interest in Multiple Representation of Codefend-ants, 71 J. Crim. L. & Criminology 529, 537 (1980).
While Holloway involved a situation in which defense counsel had expressly informed the court of the possibility *677of a conflict, its reasoning was extended in Cuyler v. Sullivan, 446 U.S. 335, 64 L. Ed. 2d 333, 100 S. Ct. 1708 (1980) and Wood v. Georgia, 450 U.S. 261, 67 L. Ed. 2d 220, 101 S. Ct. 1097 (1981). In Sullivan, the Court noted that Holloway imposed no general duty to inquire about the possibility of conflict but held nevertheless that a defendant who shows that "an actual conflict of interest adversely affected his lawyer's performance" was entitled to relief even absent a showing of prejudice. Sullivan, at 348, 349-50. In Wood, the Court further clarified the duty to inquire by noting that "Sullivan mandates a reversal when the trial court has failed to make an inquiry even though it 'knows or reasonably should know that a particular conflict exists."' Wood, at 272 n.18 (quoting Sullivan, at 347).
Taken together, Holloway, Sullivan, and Wood create two rules. First, a trial court commits reversible error if it knows or reasonably should know of a particular conflict into which it fails to inquire. Second, reversal is always necessary where a defendant shows an actual conflict of interest adversely affecting his lawyer's performance. In neither situation need prejudice be shown.
The application of these rules is not limited to joint representation of codefendants. While most of the cases have involved that fact situation, the rules apply to any situation where defense counsel represents conflicting interests. See, e.g., Wood, at 266 (defense counsel paid by defendant's employer); Sullivan, at 337-38 (representation of codefend-ants in separate trials); Alexander v. Housewright, 667 F.2d 556, 558 (8th Cir. 1981) (previous representation of prosecution witness in action against defendant); Stephens v. United States, 595 F.2d 1066, 1070 (5th Cir. 1979) (simultaneous representation of prosecution witness and defendant); Castillo v. Estelle, 504 F.2d 1243, 1245 (5th Cir. 1974) (simultaneous representation of defendant in criminal trial and prosecution witness in unrelated civil litigation). That simultaneous representation of a defendant and a witness with opposing interests is such a situation is self-evident— indeed, we only recently suspended an attorney from the *678practice of law for placing himself in a virtually identical situation. See In re McMurray, 99 Wn.2d 920, 665 P.2d 1352 (1983) (violation of CPR DR 5-105 to represent defendant after prior representation of prosecution witness in unrelated civil proceeding).
C
In the present case, the trial court had a duty to inquire into the possibility of conflict. Mr. Clemmer stated in open court that Mr. Richardson's attorney was also his. The court itself recognized the danger of conflict arising from this joint representation, as is demonstrated by its proper refusal to allow Mr. Richardson's attorney to advise Mr. Clemmer about his testimony.
Yet the court made no further inquiry into this apparent conflict despite the fact that Mr. Richardson's attorney completely dropped his line of questioning about the alleged skimming by Mr. Blackwood. Indeed, the court affirmatively cut off Mr. Clemmer's explanation of his relationship with defense counsel. To paraphrase the Supreme Court: "The possibility of the [conflict of interest] was brought home to the court, but instead of jealously guarding [Mr. Richardson's] rights, the court may fairly be said to be responsible for creating a situation which resulted in the impairment of those rights." Glasser v. United States, 315 U.S. 60, 71, 86 L. Ed. 680, 62 S. Ct. 457 (1942). While the court's action in the present case may be more accurately characterized as benign neglect, it still falls far short of the active protection required by Holloway, Sullivan, and Wood.
Unfortunately, because Mr. Clemmer was cut off by both defense counsel and the trial court, the record does not reveal the precise nature of Mr. Clemmer's relationship with defense counsel. This information is necessary to resolve the present case, for the conflict of which the trial court reasonably should have known must also actually exist. See Wood, at 273 (remanding for hearing "to determine whether the conflict of interest that this record *679strongly suggests actually existed"). Mr. Richardson has, however, established a prima facie case of error based on the record before us.
Ordinarily, as noted above, one raising error in a personal restraint petition must also prove by a preponderance of the evidence that the error was not harmless, i.e., that it was prejudicial. In re Hagler, 97 Wn.2d 818, 826, 650 P.2d 1103 (1982). Where, as in the present case, however, the error which is alleged gives rise to a conclusive presumption of prejudice, proof of the error automatically provides proof of the prejudice. Cf. In re Hews, 99 Wn.2d 80, 88, 660 P.2d 263 (1983) (proof of constitutional invalidity of guilty plea constitutes proof of actual prejudice). See also United States v. Frady, 456 U.S. 152, 170, 71 L. Ed. 2d 816, 102 S. Ct. 1584 (1982) (indicating that prejudice requirement for federal habeas corpus relief would always be satisfied if error was one which was per se prejudicial). Thus, no independent showing of prejudice is necessary here.
Since Mr. Richardson has established a prima facie case of prejudicial error, but one which is not dispositive, we must remand to the Superior Court for further factfinding. See In re Hews, supra at 88-89. At the hearing, the Superior Court should determine the nature of Mr. Clemmer's relationship with defense counsel and whether or not it posed an actual conflict of interest. If it did, Mr. Richardson's petition should be granted. If there was no actual conflict, the petition should be denied.
Williams, C.J., Stafford, Brachtenbach, and Dolliver, JJ., and Cunningham and Henry, JJ. Pro Tern., concur.
Mr. Richardson testified:
Somebody, which I do not know who was on me, grabbed me, hit me, and when they grabbed me I grabbed for the gun, and then I was hit, and I went down.
When I was hit, and I went down then falling, and it just a fine line there that when I was going down only thing I felt was a jolt in my hand and honest — honest, I don't remember cocking the gun or pulling the trigger, but when
I went down I felt a jolt in my hand.
Report of Proceedings, at 658. A police officer gave hearsay testimony that Mr. Richardson's attorney told him that Mr. Richardson had said the shooting was an accident; however, Mr. Richardson never stated this directly and the attorney, of course, never took the stand to explain this hearsay.