This appeal presents the unusual situation of the Government conceding a claim which is usually hotly contested— that the appellant suffers from permanent retrograde amnesia as a result of which he has no recollection of any of the events alleged in the indictment. The question raised on appeal is whether it is a denial of due process or of the right to effective assistance of counsel to try a defendant suffering from such a loss of memory.
Appellant was tried and convicted in five counts of assault with a pistol and robbery. The evidence presented at trial was certainly sufficient to sustain the conviction absent the amnesia. The testimony revealed that on October 2, 1964, at about 9:00 P.M., Gerald Fells, who had just parked his car and begun walking down the street, was robbed at gunpoint by two men who took his car keys and stole his car. The robbers held handkerchiefs to their faces and consequently Mr. Fells could not make a positive identification. Nevertheless he testified at trial that appellant “closely resembled” one of his two assailants.
A short time later, at about 9:20 P.M., two men held up a pharmacy on Connecticut Avenue and escaped with over $400 in cash and three bottles of the drug desputal. At trial an employee of the pharmacy positively identified appellant as one of the robbers. Soon after the robbery a police lookout was broadcast for two Negroes driving Mr. Fells’ yellow Mustang and believed to have committed the pharmacy holdup. Two officers in a police cruiser spotted the stolen car heading south on Connecticut Avenue and began to pursue it. During the ensuing high-speed chase the suspects’ stolen car missed a curve, ran off the road, and crashed into a tree. One of the two men found in the demolished car was dead; the other, the appellant here, was unconscious. Money, a gun, a bottle of desputal, some of Mr. Fells’ effects, and a stocking mask and hat resembling those worn by the robbers were found scattered about the wreckage.
In the accident appellant fractured his skull and ruptured several blood vessels in his brain. He remained unconscious for three weeks. He still suffers from *462a partial paralysis and a slight speech defect. He cannot now, and almost certainly never will, remember anything that happened from the afternoon of the robberies until he regained consciousness three weeks later. Except for this memory loss appellant’s mental condition is normal. He suffers from no mental disease or defect, and apparently never has.
On February 23, 1965, appellant was committed to St. Elizabeths Hospital for a mental examination pursuant to 24 D.C.Code § 301 (1967). The hospital reported that, although appellant was now of sound mental health, his amnesia rendered him incompetent to stand trial. On the basis of that report, the District Court judge held a competency hearing, found appellant incompetent to stand trial, and committed him to the hospital, where he remained for 14 months.1 Then, in August 1966, the hospital re-examined its position and concluded that since appellant was not now suffering from mental disease or defect, and probably was not suffering from such a disorder at the time of the crime, there were no grounds to keep him hospitalized. The court was invited to “make appropriate disposition” of the case. Accordingly Judge McGuire held a second competency hearing in September 1966. The Government’s witness, Doctor Economon, testified that appellant had permanent retrograde amnesia and would not be able to aid in his own defense in terms of remembering any of the acts alleged in the indictment. He had “no doubt” that appellant was not feigning. However, the doctor also testified that the appellant did have a rational understanding of the charges against him, that the suffered from no mental disorder, and that, but for the amnesia and slight physical sequelae of the accident, he was in good health. On November 25, 1966, Judge McGuire filed a memorandum opinion finding appellant competent to stand trial. United States v. Wilson, D.D.C., 263 F.Supp. 528.
Judge McGuire abjured a per se approach to the question of incompetency by reason of amnesia, opting instead for a case-by-case determination of competency :
“* * * [T]his Court holds that amnesia per se in a case where recollection was present during the time of the alleged offenses and where defendant has the ability to construct a knowledge of what happened from other sources and where he has the present ability to follow the course of the proceedings against him and discuss them rationally with his attorney does not constitute incompetency per se, and that a loss of memory should bar prosecution only when its presence would in fact be crucial to the construction and presentation of a defense and hence essential to the fairness and accuracy of the proceedings.
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«* * * [T]he rule to be applied in this case is whether insufficient information concerning the events at the time of the commission of the crime and evidence relating thereto is available to the defense so that it can be said that the presence of such an amnesia as we have here precipitates a situation in which defendant’s memory is indeed a faculty crucial to the construction and presentation of his defense. * * * ” 263 F.Supp. at 533—534.
He concluded that, because “there has been no showing of the unavailability *463from sources extrinsic to the defendant of substantially the same information that his present independent recollection could provide if functioning, defendant’s motion to be adjudged incompetent to stand trial is denied.” Id. at 534. Judge McGuire left open to defense counsel renewal of his claim of incompetence if formal discovery and other sources of information did not disclose sufficient facts to enable appellant to receive a fair trial. Appellant renewed his claim of incompetency before trial, but Judge Mc-Garraghy, the trial judge, found appellant competent. He was then tried without a jury and convicted.
We agree with Judge McGuire’s general approach to assessing the question of competency. However, we remand to the trial judge for more extensive post-trial findings on the question of whether the appellant’s loss of memory did in fact deprive him of the fair trial and effective assistance of counsel to which the Fifth and Sixth Amendments entitle him.
The Government relies on our decision in Hansford v. United States, 124 U.S.App.D.C. 387, 365 F.2d 920 (1966), to argue that amnesia, without an accompanying mental disease or defect, can never render the accused incompetent to stand trial. It cites a Yale Law Journal note, Amnesia: A Case Study in the Limits of Particular Justice, 71 Yale L.J. 109 (1961), for the proposition that “there is no record of any court holding a defendant incompetent to stand trial solely on the basis of amnesia.” Id. at 116. But as that same article points out, this doctrinaire approach produces anomalous results. “[F]or while the policy underlying the doctrine of competency focuses on the impairment of the rational ability of the accused to conduct his defense, the rule presently applied by the courts is conditioned upon the fortuitous presence of a narrowly defined mental disorder.” Ibid. Instead, as Judge McGuire said, the question must come down to whether, “in the light of the personal intellectual or emotional deficiencies of the accused he can perform the functions essential to the fairness and accuracy of the particular proceedings in which he is presently involved.” 263 F.Supp. at 533.
Whether the accused suffers from a mental disorder as defined in the American Psychiatric Association Manual is not decisive. Nor is it enough that the evidence of the defendant’s guilt is substantial. He is entitled to a fair trial as well as a trial in which he is proven guilty. To have a fair trial the defendant must be competent to stand trial. The test of competency must be whether he has sufficient “present ability to consult with his lawyer with a reasonable degree of rational understanding — and whether he has a rational as well as factual understanding of the proceedings against him.” Dusky v. United States, 362 U.S. 402, 80 S.Ct. 788; 4 L.Ed.2d 824 (1960). The accused must be able to perform the functions which “are essential to the fairness and accuracy of a criminal proceeding.” Pouncey v. United States, 121 U.S.App.D.C. 264, 266, 349 F.2d 699, 701 (1965).
A prediction of the amnesic defendant’s ability to perform these functions must, of course, be made before trial at the competency hearing. But where the case is allowed to go to trial, at its conclusion the trial judge should; determine whether the defendant has in fact been able to perform these functions. He should, before imposing sentence, make detailed written findings, after taking any additional evidence deemed necessary,2 concerning the effect of the amnesia on the fairness of the trial. In making these findings the court should consider the following factors:
(1) The extent to which the amnesia affected the defendant’s ability to consult with and hssist his lawyer.
(2) The extent to which the amnesia affected the defendant’s ability to testify in his own behalf.
*464(3) The extent to which the evidence in suit could be extrinsically reconstructed in view of the defendant’s amnesia. Such evidence would include evidence relating to the crime itself as well as any reasonably possible alibi.
(4) The extent to which the Government assisted the defendant and his counsel in that reconstruction.
(5) The strength of the prosecution’s case. Most important here will be whether the Government’s case is such as to negate all reasonable hypotheses of innocence.3 If there is any substantial possibility that the accused could, but for his amnesia, establish an alibi or other defense, it should be presumed that he would have been able to do so.
(6) Any other facts and circumstances which would indicate whether or not the defendant had a fair trial.
After finding all the facts relevant to the fairness of the trial, considering the amnesia, the court will then make a judgment whether, under applicable principles of due process, the conviction should stand.4
If the court determines that the conviction may not stand because of the unfairness of the trial caused by the defendant’s amnesia, the court will vacate the conviction and give the Government an opportunity to retry the case. If on retrial the Government is unable to overcome the unfairness which would have thus voided the first conviction, the indictment will be dismissed.
So ordered.
. It is unclear why appellant, who was not then suffering from any mental disease or defect, was committed to St. Elizabeths. 24 D.C.Code § 301(a) states that if the accused is found to be “of unsound mind or mentally incompetent to stand trial,” the court shall order him confined to a hospital for the mentally ill until he is restored to mental competency. But as Judge McGuire recognized in his memorandum opinion following the second competency hearing, since appellant “is not presently insane or potentially dangerous to himself or others, [his] commitment under the terms of 24 D.C.Code, § 301(a) would be illegal.” United States v. Wilson, D.D.C., 263 F.Supp. 528, 531 (1966).
. Assuming appellant waives his privilege, defense counsel may well be an invaluable witness on the question of the extent to which his client’s amnesia affected his preparation of the case.
. Compare Holland v. United States, 348 U.S. 121, 139, 75 S.Ct. 127, 99 L.Ed. 150 (1954), in which the Supreme Court held that ordinarily the judge need not, even in a circumstantial evidence case, charge the jury that to convict it must find that the Government’s case negates every reasonable hypothesis of innocence. See also Hunt v. United States, 115 U.S.App.D.C. 1, 316 F.2d 652 (1963). The Fifth Circuit has adhered to this formulation as the standard for the trial judge in deciding whether the Government’s case, if based only on circumstantial evidence, should go to the jury. See, e. g., Cuthbert v. United States, 5 Cir., 278 F.2d 220, 224 (1960).
. It would of course be desirable that defendants not only be competent to stand trial, but also have present awareness of their whereabouts and activities at the time of the crime of which they are accused. But courts have not considered such awareness as an essential ingredient of competence itself. As Judge Leventlial points out, the man accused of committing a crime while drunk may have no recollection concerning the alleged events. And in the so-called “delayed arrest” narcotics cases, while the guilty man may remember his crime, the innocent accused may remember nothing at all about his activities at the critical time. Yet this court, while acknowledging that a delayed arrest may entail loss of memory, has never considered such lack of memory as going directly to competence to stand trial. Instead, it has required that where there has been substantial delay in arrest there can be a conviction only if the Government’s case has strong corroboration. See, e. g., Ross v. United States, 121 U.S.App.D.C. 233, 349 F.2d 210 (1965). This approach, like that of Judge McGuire in the instant case, makes the probability of prejudice, not lack of memory per se, controlling.