(dissenting):
In a joint trial, appellants were convicted by a jury of second degree murder; 1 Clayborne was also convicted of carrying a pistol without a license. The court today holds that the failure of trial counsel to interview or cross-examine the government’s key witness did not deny appellants the effective assistance of counsel.2 I cannot agree.
I.
An extensive discussion of the facts in this case is required to place the issue in proper perspective.
A. Pre-Trial
On May 18, 1971, six days after an insurance agent was shot, a Ms. Connie Jackson, fifteen years old, called the police stating she had information regarding the shooting. In her mother’s presence, Ms. Jackson told the police the following story. . Appellants Clayborne and Brown came to her house on the morning of the homicide. Clayborne was carrying two bags, one with watches, the other with pistols, and unsuccessfully tried to sell some of these items to Jackson and her boyfriend.3- Shortly thereafter, Mr. Spiro, an insurance agent, arrived and inquired if Ms. Jackson’s mother was at home. When told that she was not, he left. Thereupon, appellants “started whispering to each other and then they left.” Jackson went upstairs to watch from her window and “saw the insurance man and [Clayborne] fighting and [Brown] was standing a little ways away watching. The insurance man ran down the steps and [Clay-borne] ran down the steps behind him and shot him,” apparently with one of the guns previously shown to Jackson. During this time, Brown was holding the bag with the other gun and the bag with the watches. After the shooting, appellants fled in opposite directions, and five minutes later Clayborne returned to his apartment which was located near Ms. Jackson’s.
Jackson further stated that on the day of the shooting she had “told her mother that the insurance man had been shot and that [Clayborne] did it. Mother was mad and said it didn’t make no sense. She told me not to tell the police.” In response to a question from the investigating officer, Jackson stated that she eventually called the police be*484cause “I got mad with Shela,” who apparently was Claybome’s girlfriend.
Two months later, Jackson’s statement to the police was read to her before a grand jury. When asked if there were any changes, she stated that Brown never held either bag.4 A juror attempted to ascertain what happened with Shela that led Ms. Jackson to call the police, but the U. S. Attorney interrupted the question and dismissed the witness.
At a status hearing- on April 14, 1972, counsel for Brown advised the court that the U.S. Attorney “did not want the defense talking to [Ms. Jackson before trial].” The U.S. Attorney replied that the witness had been threatened, although not by counsel for either appellant. He said further that Jackson’s mother had sent her outside the jurisdiction to live with a relative because she was afraid. Despite persistent argument by the prosecutor, however, the court ruled that counsel were entitled to interview the witness, and discussed possible ways in which they could do so.
One week later, at a status hearing on April 21, 1972, the U.S. Attorney informed the court that he was mistaken when he stated that Jackson had left town. He suggested that she could be brought to the courthouse so counsel could interview her. The court advised counsel to get together with the U.S. Attorney and “work out a date [to interview the witness] convenient to all.”
B. Trial
On the opening day of trial, two months after the April 21 status hearing, counsel advised the court that none of the defense attorneys had interviewed Ms. Jackson. “If there is a question about a threat being made to any witness, I want to make sure that [defense counsel] are a long way from that scene.” A U.S. Attorney other than the one who had appeared at the status hearings responded that “[defense counsel] are not to be considered as having anything to do with any possible threats to the witnesses. This is a tight community [where the witnesses and appellants live], and any threats came from the peer groups.”
When Ms. Jackson was called to testify she refused to answer any questions because “it might incriminate me.” The court appointed counsel to represent her, and, after a brief conference with his client, counsel informed the court that her refusal to testify was due to fear of reprisal. Thereupon, the. jury was excused, and in Jackson’s presence her police statement and grand jury testimony were read into the record. The U.S. Attorney then resumed questioning, still outside the presence of the jury, and the witness contradicted her former statements by claiming that Clayborne never had a bag with watches. The court advised the prosecutor to “consider the indictment for perjury,” and instructed the witness that perjury is a “fifteen year penitentiary sentence.” Nonetheless, Jackson refused to answer the next question, and the following colloquy ensued:
The Court: Very well. Let me tell you now what you are faced with. You are going to be faced with two contempt charges. I will leave it to the United States Attorney to prepare the necessary form for criminal contempt, and if I am not mistaken without a jury trial you can be put in jail for as much as six months. I may well hold a jury trial, which then puts — What is the maximum there?
*485[Counsel for Ms. Jackson]: I think a year.
The Court: . . . The second thing, without any such consuming efforts, I hold you in civil contempt and I commit you to the District of Columbia Jail until such time as you purge yourself by coming here and giving the answers here in Court. Do you understand? Take her away. She is committed to jail.
Jackson’s counsel then informed the court “that she was told by some prosecutor that she would not have to testify in open court and she would not have to face the Defendants with her testimony.” After a bench conference, Jackson was told by the court that she would not be placed in jail that evening; instead she and her mother would be put in protective custody by the U.S. Attorney for the night, “[b]ut I can assure you this, Miss Jackson: If you continue to refuse to testify tomorrow morning, I shall see to it that you are in jail by noon tomorrow and that you will remain there until you are willing to testify.”
The following morning, before the jury was brought in, Jackson answered several questions asked by the U.S. Attorney. The court inquired if she remembered her statement to the police and her grand jury testimony, and if “your testimony today [is] going to be along the same line?” Counsel for Brown immediately requested a bench conference and indicated that he thought the court’s question “raises a very sensitive area in that( the witness, of course, should testify truthfully as to what she currently recalls happening on [the date of the shooting].” The court agreed, and said he would instruct the witness to testify “truthfully.” Before he could do so, however, counsel for Clayborne moved to exclude Ms. Jackson’s testimony “on the grounds that [it] is coerced and therefore inherently probable that it could not be the truth.” The court responded that counsel could explore the circumstances in which she agreed to testify, and whether her testimony was coerced, on cross-examination. A discussion ensued in which counsel for Clay-borne requested that he be allowed to interview Ms. Jackson “for two purposes”: first, because the U.S. Attorney had “kept her from us during the entire length of this case”, and second, “to find out what has happened since she left Court yesterday.” The court asked, “[H]ow did [the U.S. Attorney] keep her from you?” Counsel replied, “[W]e didn’t have her name or know where she lived.” The court suggested that Clay-borne certainly knew the witness’s name and address, but counsel responded, “Clayborne claims not to know who the witness would have been.” Brown’s counsel then stated that “I was aware of who the witness was.” And Clayborne’s counsel followed, “[e]ven if we were remiss in not finding her all this time, we should have an opportunity to ask her— We have no way of cross-examining.” Clayborne’s counsel then switched tactics and argued only that he should be allowed to interview the witness regarding the events of “the last 12 or 18 hours.” The court granted a recess so that counsel could interview Jackson regarding the events that transpired since the close of court on the preceding day, and instructed the court reporter, counsel for Ms. Jackson, and Ms. Jackson’s mother to be present.
At this conference Jackson stated that the previous night she had discussed the case with her mother who told her to “tell the truth,” and that that morning she had reviewed her police statement with the U.S. Attorney. The interview concluded with the following exchange:
[Counsel for Brown]: As a result of your conversations with your mother and [the U.S. Attorney], do you feel now that you have to testify exactly the same way as you did in the statement you made to the police and before the Grand Jury?
The Witness: Yes.
[Counsel for Brown]: Do you feel that if you don’t testify the same way it will be considered perjury on your part?
The Witness: Yes.
*486[Counsel for Brown]: And do you feel that you, therefore, must say what you said before, even though in your own mind now you might not remember it the same way?
The Witness: Yes.
[Counsel for Brown]: So if you re-
member things differently, you still feel that you have to say what you said before in order not to be guilty of perjury? Is that true?
The Witness: Yes.
Based on this interview, counsel for Brown informed the court that he no longer believed that the events of the preceding day were “merely factors affecting [Ms. Jackson’s] credibility as a witness, . . . [but now thought] her testimony will be so inherently incredible and untrustworthy that as a matter of law she should not be permitted to testify.” The court, outside the presence of the jury, then ordered the transcript of the interview read into the record. After hearing it, he decided that he would reinstruct the witness, “out of the presence of the jury,” to testify to “the truth as she knows it and nothing else.” Brown’s counsel asked if the court would also “state to the witness that even if she remembers things differently from what she may have remembered previously, she should say now what she remembers.” The court replied, “[n]o, ... If you think there is something on cross-examination you can properly develop, you can do so. It is not for me.”
The witness was called and instructed to tell “the truth and only the truth.” She testified essentially to what was in her police statement. At first, when asked if Brown was holding the bags while Clayborne was fighting with the insurance man, she said yes. Shortly thereafter, however, when asked if Brown had anything in his hands, the witness replied, “[n]o, I don’t remember.” The U.S. Attorney was permitted to refresh her memory by having her read her police statement. She was not, however, shown her grand jury testimony, where she stated that Brown was not holding either bag. After reading her police statement, she testified that she now remembered that Brown was holding “two bags.”
After a luncheon recess, counsel for Clayborne advised the court, “[o]nce the jury comes back I am going to announce that I am not going to cross-examine this girl and I am going to ask the Court to hold her for possible leave to cross-examine her later, although I don’t anticipate it. The reason I am putting this on the record now is it is a tactic on our part which we think will help the Defendant. So when the record goes upstairs — ” At that point, the court interrupted, and told counsel that if he planned to cross-examine Ms. Jackson he would have to do so immediately. Counsel declined to do so. Counsel for Brown then stated that he would not cross-examine Ms. Jackson.
Another government witness testified that he had spoken with Clayborne on the day of the homicide, and had asked, “[d]id you do it?”, to which Clayborne responded, “[y]es.” By “it,” the witness said he meant the robbery 5 of the insurance man. On cross-examination, the witness stated that he thought Clay-borne was “jiving” when he claimed to have done “it,” since he was laughing at the time, and that was Clayborne’s manner of joking.
The only witness for the defense was Clayborne who testified that he had stayed at home on the day of the homicide. He said Jackson had visited him in jail nine or ten times, and had told him that her police statement was untrue. She said her mother had “put her up to it” because of a $5000 reward that had been offered by the insurance company.6
*487C. Post-Trial
Three months after trial — and five days after appellant Clayborne filed notice of his appeal — counsel for Clayborne moved to file a “Statement Concerning Counsels’ Decision Not To Cross-Examine [Ms. Jackson].” The reason for this motion was:
In the case at bar the decision to not cross-examine the key Government witness would need no explanation to experienced trial lawyers thoroughly familiar with the facts in the case. However, counsel is aware that many appellate counsel have not tried a criminal case and the fact that trial counsel did not cross-examine the only real Government witness would constitute ineffective assistance per se. Also, the Appellate Court, although presumably experienced trial counsel in the past, may not be sufficiently apprised of the underlying reasons why such a tactic is pursued.
The court granted this motion. The “Statement” contained the following reasons for not cross-examining:
1. To preserve counsels’ position that the witness should not have been permitted to testify.
2. To preserve counsels’ position that counsel should have been permitted to speak to Miss Jackson before she testified concerning her testimony.
3. The young witness had broken down twice and she presented a very sympathetic witness to the jury and a very difficult witness for any counsel to cross-examine.
4. Miss Jackson’s direct testimony did not give a factual basis to support a charge of robbery or attempted robbery necessary for a felony-murder conviction. Had Miss Jackson been permitted by way of cross-examination or by a leading re-direct question to explain fully what allegedly occurred between the deceased and the defendant, James Clayborne, evidence of an attempted robbery most certainly would have come out.
5. Had Miss Jackson been permitted to explain in detail the manner in which the deceased had been allegedly shot by Mr. Clayborne there could well have been sufficient evidence to support the element of premeditation as a part of First Degree Murder.
6. Mr. Clayborne’s defense could be presented without the cross-examination of Miss Jackson. Further, Mr. Clayborne’s defense might well put the Government in a position requiring it to recall Miss Jackson in rebuttal to discredit Mr. Clayborne’s testimony that she was lying in order to get reward money. If that occurred counsel would then be in a position to freely cross-examine Miss Jackson without the fear of a First Degree conviction.
Appellants contend: (A) that their counsels’ failure to cross-examine Ms. Jackson was the product of inadequate investigation and preparation; and (B) that they were substantially prejudiced as a result since Miss Jackson was the only witness of consequence, and she could have been significantly impeached if not rendered wholly incredible. Therefore, appellants argue, they were denied their sixth amendment rights to the effective assistance of counsel.
A
In anticipation of a claim of ineffectiveness, Clayborne’s counsel7 filed a “Statement” in the record below to advise this court that their decision not to cross-examine Ms. Jackson was a trial “tactic.”8 Appellate counsel (who was *488not trial counsel) flatly asserts that trial counsel did not, and indeed could not, cross-examine the witness because they neither interviewed her before trial, nor adequately researched the legal questions at issue. In United States v. De-Coster, 159 U.S.App.D.C. 326, 487 F.2d 1197, 1201 (1973), we stated:
This court does not sit to second guess strategic and tactical choices made by trial counsel. However, when counsel’s choices are uninformed because of inadequate preparation, a defendant is denied the effective assistance of counsel. (Emphasis supplied.)
To insure “adequate preparation,” we delineated certain specific duties owed by counsel to his client, including “interview[ing] not only his own witnesses but also those that the government intends to call,” and doing “adequate legal research.” In enumerating these obligations, we did not announce new standards for trial counsel,9 but simply brought together a check list of responsibilities heretofore required, depending, of course, on the circumstances of a given case.10 Indeed, in the present ease, the court and defense counsel all agreed that counsel would attempt to interview this witness. And despite strenuous objections by the prosecution, the court insisted that she be made available to the defense.
The failure of counsel to interview Ms. Jackson and to do adequate research lays behind five of the six proffered reasons for not cross-examining her.11 Two of the five reasons rested on counsels’ fears that the testimony elicited would provide evidence either of a robbery or premeditation, and thereby subject appellants to a first degree murder conviction. Counsel did not act to determine whether these fears were justified. Because they failed to interview Ms. Jackson,12 they were compelled to proceed on their bare speculation as to what she would reveal on cross-examination. Where important information is available to diligent counsel, such speculation is hardly an acceptable substitute.
Counsel also claim that they did not cross-examine because they wanted to preserve their positions taken at trial that Ms. Jackson should not have been allowed to testify at all, or that counsel were entitled to interview her before she testified about matters other than what transpired while she was in protective custody. These reasons were predicated upon an erroneous understanding of the governing case law. Once the court ruled against counsel, they were entitled to do what they “fairly could to limit the prejudicial impact of the[se] ruling[s],” without waiving any appeal with respect to the initial objections.13
Counsel’s final reason for not cross-examining was that Clayborne’s defense *489could be presented without their doing so. This naked conclusion, however, seems highly untenable since appellant’s whole defense appeared to rest on destroying Ms. Jackson’s credibility.
Counsel’s own “Statement”, then, makes it abundantly clear that their decision not to cross-examine Ms. Jackson was uninformed because of a failure to adequately research or investigate their case. Indeed, Clayborne’s attorney admitted as much when he told the court that, having failed to interview the witness, “[w]e have no way to cross-examine [her].” 14
B
Appellants further contend that they were greatly prejudiced by counsel’s failure to engage in cross-examination. Ms. Jackson was a critical witness and might have been severely impeached on several grounds:
1) Counsel could have brought out the fact that the witness agreed to testify only after she was threatened with a contempt citation and an indictment for perjury. By her own admission, Jackson indicated that she felt compelled to testify “exactly the same way as [she] did in the statement [she] made to the police and before the Grand Jury even though in her own mind now [she] might not remember it the same way.”
2) Counsel could have inquired if the witness knew about a published reward of $5000,15 and whether the reward influenced the witness or her mother, as Clayborne claimed Jackson told him it had done.
3) Counsel could have asked about Jackson’s assertion to the police, alluded to before the grand jury, that she called the police because she was “mad with Shela,” Clay-borne’s girlfriend.
4) Counsel for Brown could have impeached the witness with her grand jury testimony to the effect that Brown was not holding “any bag at any time.” This evidence was particularly crucial since Jackson vacillated on this point on direct examination, and only stated that Brown was holding the bags after reading her police statement. Moreover, the government’s case against Brown was weak, and turned largely upon the evidence that he held the bags while Clay-borne assaulted the insurance agent.16 ■
Prior to DeCoster, supra, an appellant was required to show that counsel’s failure to meet his obligations “blotted out the essence of a substantial defense.” 17 However, in DeCoster, recently held retroactive in United States v. Butler,18 we held that once an appellant shows a violation of the “precepts” delineated therein, the government must prove “lack of prejudice.”19 There has been no such showing. Indeed, appellants have clearly satisfied any reasonable view of even their pre-DeCoster burden. They rely on significant matters which might have seriously undercut the witness’s credibility. And theré may well have been other *490such factors that we do not know of precisely because counsel neither interviewed nor cross-examined the witness.20 On the other hand, the justifications provided by counsel for not cross-examining, with one exception, are traceable to inadequate research or speculation necessitated by the failure to interview the witness. In short, appellants have demonstrated that counsels’ inadequacies either “blot[ted] out” their sole defense, or prejudiced their ability to show that their defense was blotted out.21 No more can be required under the most stringent test.
. Appellants were indicted for first degree felony murder, first degree premeditated murder, attempted robbery while armed, and attempted robbery; Clayborne was also indicted for carrying a pistol without a license. At the close of the government’s case, the trial court directed verdicts of acquittal on all the robbery counts, the felony murder counts, and the premeditated murder charge with respect to Brown. Brown was kept “in the case on second degree murder as an aider and abettor.” The jury acquitted Clayborne on the premeditated murder charge, and convicted both appellants of second degree murder.
. Relying heavily on Bailey v. United States, 135 U.S.App.D.C. 95, 416 F.2d 1110 (1969), appellant Brown argues that the trial court’s refusal to enter a judgment of acquittal on all counts against him was erroneous. The critical distinction between this case and Bailey is that here there was “guilty participation” by Brown in that he held the bags while Clayborne accosted the insurance agent. See p. 483 infra.
Appellant Clayborne argues that it was erroneous for the trial court to fail to direct a verdict of acquittal on his premeditated murder charge. Since he was acquitted by the jury on this count, however, appellant’s challenge is answered by our opinion in United States v. Dent, 155 U.S.App.D.C. 278, 477 F.2d 447 (1973).
. Jackson testified that her boyfriend was present during these events, although the record 'does not indicate whether he observed the shooting. The government claimed that it attempted to locate this witness but was unsuccessful. Defense counsel also indicated that they made a cursory effort to discover his whereabouts. Nothing further is reflected in the record, and the witness was unavailable for trial. The court denied appellants’ request to “refer” to this missing witness.
. The context of the testimony is a bit confused. After hearing her statement to the police read to the grand jury, Jackson and the U. S. Attorney engaged in the following conversation:
Jackson: And where — [Clayborne] had two bags. [Brown] didn’t have no bags.
U.S. Att’y: [Clayborne] had two bags; is that correct.
Jackson: (Nodding).
U.S. Att’y: And he showed you the gun in one of the bags? And were there watches in the other bag?
Jackson: (Nodding).
U.S. Att’y: And did William have any bag at any time?
Jackson: Uh-uh, no.
At that point the discussion changed to a different subject.
. Since there had been no testimony regarding a robbery of the insurance agent, the court ordered the witness’s reference to a robbery stricken from the record.
. The insurance company had in fact offered such a reward. See Washington Post, May 16, 1971 at A-5 cols. 1 & 2.
. Counsel for Brown did not join this “Statement.” However, at the close of the “Statement”, Clayborne’s counsel indicated that “[ajll four defense counsel felt that the tactic not to cross-examine Miss Jackson prevented a First Degree conviction.” Thus, although we do not have an explicit statement from Brown’s counsel as to why they did not cross-examine, it appears that the reasons are similar to those offered by Clayborne’s counsel. Moreover, since the case against Brown was weak, and since Ms. Jackson could have been significantly impeached by her grand jury statement, the need to cross-examine her was that much greater for Brown’s counsel than it was for Clayborne’s counsel.
. At trial, Clayborne’s counsel explained that he was not cross-examining Ms. Jackson because “it is a tactic on our part which we think will help the Defendant.”
. To my knowledge, no member of this court has ever even suggested that “obtaining a complete acquittal ... be the measure of a defense lawyer’s . . . effectiveness [in Sixth Amendment cases].” Majority Opinion at p. 478. Rather, we — and the Constitution — demand simply that all defendants be given "the reasonably competent assistance of an attorney acting as his diligent conscientious advocate.” United States v. DeCoster, 487 F.2d 1197, 1202 (1973).
. See, e. g., United States v. Hammonds, 138 U.S.App.D.C. 166, 425 F.2d 597 (1970); Matthews v. United States, 145 U.S.App.D.C. 323, 449 F.2d 985 (1971); United States v. Thompson, 154 U.S.App.D.C. 347, 475 F.2d 931 (1973); United States v. Benn, 155 U.S.App. D.C. 180, 476 F.2d 1127, 1132-1135 (1973) (opinion of Bazelon, C. J.).
. The only offered reason not directly dependent on counsel’s lack of preparation was that Ms. Jackson was a sympathetic witness and that therefore cross-examination might alienate the jury.
. The conversations that Jackson may have had with Clayborne while he was in jail, page 486, supra, cannot be regarded as substitutes for comprehensive interviews conducted by counsel. Indeed, if, as Clayborne testified, Jackson told him that she had lied to the police, the need for an interview would seem even more compelling.
. United States v. Maynard, 155 U.S.App. D.C. 223, 476 F.2d 1170, 1175 (1973).
. See McCormick, Evidence § 30 (1954) (“preparation before trial is the only soil from which, in the day-to-day run of cases, successful cross-examination can grow.”).
. Failure to introduce evidence of the reward resulted in the following interruption of Clay-borne’s closing argument:
Counsel: . . . Meanwhile the insurance company puts up a reward—
The court: I never heard any evidence on this. Disregard that, ladies and gentlemen. There is no evidence in this case anybody put up any reward.
Evidence of a reward “may affect the credibility of a witness for the prosecution.” 3A Wigmore § 969 (Chadbourn rev. 1970). See Wheeler v. United States, 351 F.2d 946 (1st Cir. 1955); Harris v. United States, 83 U.S. App.D.C. 348, 169 F.2d 887 (1948).
. One of the reasons for requiring the government to show lack of prejudice from counsel’s ineffectiveness is that “proof of prejudice may well be absent from the record precisely because counsel has been ineffective.” United States v. DeCoster, supra at 1204.
. Compare Matthews v. United States, 145 U.S.App.D.C. 323, 449 F.2d 985 (1971) (“counsel for [appellant’s] co-defendant did conduct cross-examination in a manner which inured substantially to the benefit of [appellant], This we think afforded effective assistance of counsel insofar as it depended on cross-examination.”).
. Compare Bailey v. United States, 135 U.S. App.D.C. 95, 416 F.2d 1110 (1969). See note 2 supra.
. See Coles v. Peyton, 389 F.2d 224, 226 (4th Cir. 1968).
. United States v. Butler, 504 F.2d 220 at 223 n. 11 (August 30, 1974) at 6 n. 11.
. United States v. DeCoster, supra 487 F.2d at 1204.