concur: This statement is filed pursuant to our order of March 28, 1957, which denied appellant’s petition for a rehearing en banc. It is occasioned by Judge Bazelon’s comments in support of his vote. We voted against granting a rehearing en banc after an exhaustive reexamination of the entire transcript which confirmed our prior conclusion that the hearings held by the trial court were not prejudicial, and the findings were supported by substantial evidence and thus were not clearly erroneous.
A brief summary of the facts in the record will aid in keeping the real issues in perspective: appellant was indicted three times in 1953 for three separate and distinct offenses committed at different times. After three separate trials before three different judges, appellant was convicted and sentenced on each charge. The three separate sentences imposed on appellant are therefore not “consecutive” in the sense that our opinions usually use that term. They are three unrelated sentences for three unrelated convictions and, of course, they must all be served.
Observation of appellant while confined led government custodial authorities to question his mental condition. Pursuant to 18 U.S.C. § 4245 a certificate was issued noting probable cause to believe that appellant was incompetent at the time of his trials. The same judges who had presided at his three trials conducted hearings1 for the purpose of determining whether or not he was sufficiently competent at the time of his trials to understand the proceedings and assist in his defense. At these hearings, each of which lasted several days,2 the issue of appellant’s mental competency was thoroughly examined. There was testimony by several psychiatrists, including the doctors who examined appellant while he was imprisoned and who issued the report certifying that there was probable cause to believe appellant was incompetent when tried and convicted. A government psychiatrist from D. C. General Hospital testified to the contrary3 on the basis *632■of his examinations of appellant shortly before the three trials. Confronted with! a genuine conflict in the testimony of; government psychiatrists, the trial judges allowed cross-examination by both the; United States Attorney and appellant’s! counsel, and the judges questioned the' witnesses rather extensively.4 In addition several police officers testified concerning appellant’s actions and demean- or preceding and during the trials and portions of Fooks’ testimony at his trials were read into the record. Appellant also testified upon request of his counsel. In short, these hearings followed the normal pattern of a judicial inquiry where it is necessary to resolve a disputed fact.
Each of the three trial judges, at the conclusion of these hearings, found that appellant had been legally competent to stand trial. This court affirmed those findings in a per curiam opinion.5
In the statement filed by Judge Bazelon it is urged a rehearing is necessary since the hearings, as conducted, distorted the fundamental scheme and de-feated the purpose of section 4245. This Conclusion rests on an assumption that the Prison Director’s certificate was de-pied prima facie effect because (1) the ,‘trial judges “imposed” upon appellant the burden of going forward with the evidence an$ (2) the trial judges permit-bed Fooks to testify in his own behalf at the request of his counsel. The purpose of this statement is to demonstrate, by explicit references to the record, that the assumption on which the conclusion rests is incorrect.
It is necessary in evaluating the objections to understand first the purpose and effect of section 4245, and second what actually took place before and during the instant hearings. Section 4245 was designed to prescribe a uniform procedure for what amounts to a “nunc pro tunc” determination of a convicted defendant’s mental competency at the time of trial where this issue “was not raised and determined before or during * * * trial.”6 The section provides that upon receipt of a certificate from the Director of the Bureau of Prisons *633stating there is probable cause to believe the prisoner was mentally incompetent when tried, the court before whom the defendant was convicted must hold a hearing. The sole purpose of the inquiry is to obtain a judicial determination of the prisoner’s “mental competency” as of the time he was tried. The statutory test of “incompetency” is not that used to determine “legal insanity,” but rather whether the accused was “unable to understand the proceedings against him or properly * * * assist in his own defense * * The court is required to vacate the conviction and grant a new trial if it finds the prisoner was, in that sense, “incompetent” to stand trial.
The hearing required by section 4245 is to be held “in accordance with the provisions of section 4244.”7 The latter section directs the trial court to hold a hearing “at which evidence as to the mental condition of the accused may be .submitted, including that of the reporting psychiatrist.” Section 4244 lends no .support to the contention that the section 4245 hearing should be conducted in some manner other than that followed in the usual judicial proceeding. Section 4245 provides further: “In such hearing the certificate of the Director of the Bureau of Prisons shall be prima facie evidence of the facts and conclusions -certified therein.”
It is apparent that the certificate, properly considered as one of the elements in a statutory scheme to determine mental competency, serves several functions: (1) it represents a medical opinion that there is probable cause to believe the prisoner was mentally incompetent when tried; (2) it operates as a pleading insofar as it requires a hearing on the issue of mental competency at the time of trial; (3) it creates a rebuttable presumption of mental ineompetency which, absent competent evidence to the contrary, controls the judicial determination.
The effect, then, of the certificate is to compel a hearing in which there is a working assumption of incompetency rather than competency. However, when evidence which would justify a finding of competency has been produced, “the presumption falls out of the case. It never had and cannot acquire the attribute of evidence in the claimant’s favor. Its only office is to control the result where there is an entire lack of competent evidence.” Del Vecchio v. Bowers, 1935, 296 U.S. 280, 286, 56 S.Ct. 190, 193, 80 L.Ed. 229.
It is erroneous to intimate that the rebuttable presumption created by the certificate places a burden of proof upon the United States Attorney or that it elevates the certificate to some independent evidentiary stature. The questions of who carries the burden of proof and the degree of probative force which the certificate retains as evidence are governed by considerations foreign to the concept of “prima facie evidence.” It is unnecessary to resolve these problems as the rulings on the point in the instant hearings were favorable to appellant. The court, in case 13,000, after hearing oral argument on the issue of burden of proof, held the burden to be on the Government. In the combined hearing involving cases 12,998 and 12,999, Judge Keech declared: “In the instant case, even assuming the burden of proof is upon the Government and that it must prove defendant’s sanity at the time of trial beyond a reasonable doubt, this court has no doubt and finds that the defendant at the time of trial was mentally competent * * United States v. Fooks, D.C.D.C.1955, 132 F.Supp. 533, 535. The certificate itself was a part of the record and was called to the court’s attention even before the hearings commenced.8 The entire report of the Board *634of Examiners at the Springfield Medical Center, Springfield, Missouri, incorporated in the certificate, was accepted in evidence in both hearings when it ivas offered.9 This report was paraphrased, several times and portions were read verbatim during the course of bota hearings.10
We find no quarrel with the suggestion that the party challenging the presumption has the burden of going forward with the evidence. See Western & Atlantic R. R. v. Henderson, 1929, 279 U.S. 639, 642, 49 S.Ct. 445, 73 L.Ed. 884. The better practice in section 4245 hearings would be for the District Court to have the certificate formally offered at the opening and then call upon the United States Attorney to produce such evidence as he might have, if any, which would meet or rebut the presumption of incompetency. This procedure will ensure technical compliance with the statute. However it does not follow that the certificate is “deprived” of its prima facie effect whenever there occurs a deviation from the desired norm. In determining this question it is necessary to look to the substance of the proceedings as well as to the form.
At the instant hearings the trial judges did not “impose” upon Fooks the burden of going forward. Counsel for Fooks did not request, at either of the hearings, a ruling on order of proof. On the contrary, the record is clear that at the outset of each hearing appellant’s counsel volunteered to go forward with his evidence. Counsel’s statement at the second hearing emphasizes this fact: “If Your Honor please, preliminarily, may I say that the statute, in my opinion, does not indicate who has either the burden of going forward or the burden of pi*oof. I assumed at a previous hearing held before other judges of this court recently the burden of going forward. I am willing to do that here, if that is Your Hon- or’s desire, but I would like to state that that is without objection or without qualification to my being able to argue the burden of proof question at such time as it may be material.”11
The record substantiates counsel’s and the courts’ judgment that it was proper for appellant to proceed since it was perfectly apparent to everyone that the United States Attorney possessed evidence in the form of four psychiatric examinations of Fooks just before trial, which would tend to meet and rebut the prima facie effect of the certificate. Prior to the commencement of the hearings the United States Attorney had informed appellant’s counsel that Dr. Perretti had examined Fooks in April and May of 1953, and had written the United States Attorney that in his opinion Fooks was mentally competent to stand trial. Counsel immediately notified the court12 *635of this fact and moved under Rule 17(b), Fed.Rules Crim.Proc. 18 U.S.C., that subpoenas issue for the doctors who had signed the Springfield report finding probable cause to believe that Fooks was incompetent when tried. Preliminary hearings were held on these motions at which appellant’s counsel argued that the conflicting medical testimony (of Government psychiatrists at Springfield and St. Elizabeths) “raises a square factual issue,” or “a question of the weight of the evidence.”13 Subsequently, when the combined hearing in cases 12,998 and 12,999 began, counsel reiterated at the very outset the obvious fact that the hearing involved a flat contradiction of medical opinion.14 It is clear that whatever the order of proof the United States Attorney was prepared to meet the presumption ; nothing could be plainer than that Dr. Perretti’s opinion as known to both counsel and the Judges, when given, would rebut the statutory effect of the certificate.15
Judge Bazelon now suggests that it is reversible error if the court does not strictly adhere to procedural niceties and rigid forms. The most that can be said for this view is that Dr. Perretti and the other government witnesses should have been called first. But no one can read Dr. Perretti’s testimony and come to any conclusion except that, had it been offered first, it would have operated to meet the presumption arising from the certificate. The sole object of these hearings was to determine the mental competency of the prisoner at the time of trial. This was accomplished even though appellant took the initiative which in no significant sense deprived the certificate of its technical prima facie effect.
The record reveals that appellant could not possibly have been prejudiced by the order in which the proof was adduced. The suggestion in the dissenting statement that had the United States Attorney been required to go forward “the prosecutor might have called the prison doctors” (emphasis added) seems to us to ignore the record. The United States Attorney had stated that he was prepared to rest his case on the testimony of Dr. Perretti. He made it very clear before the hearings began that he did not intend to call the Springfield doctors as witnesses.16 Prior to the hearings and before any question as to the order of proof could conceivably have been raised, appellant’s counsel advised the court “that it was an absolute necessity” that the doctors be subpoenaed “so that they may be examined and cross-examined, as Dr. Perretti may be.”17
Clearly the court did not make “it necessary for Fooks to bring forth witnesses” nor did counsel’s decision to request the presence of the experts have even the slightest relevance to the order of proof.
We take issue with Judge Bazelon’s view that appellant’s counsel was unduly *636limited in his examination of thes prison psychiatrists. His view seems to us to overlook the fact that at the combined hearing (which was the earlier, longer, and more exhaustive of the two hearings) appellant’s counsel was permitted to ask leading questions.18 Indeed, if a balance is to be struck, the United States Attorney in this hearing was limited in his examination to a greater extent than was appellant.19 In any case, the degree of limitation on examinations cannot be regarded as sufficient reason for claiming disregard of a statutory scheme.
The dissenting memorandum finds in the examination of appellant by his own counsel another “consequence” of depriving the certificate of its prima facie effect. The circumstance of appellant testifying in his own behalf had nothing to do with the certificate’s prima, facie effect. Counsel notified the court early in the combined hearing that he wished appellant to testify.20 The appellant’s recollection and understanding of his trials was undoubtedly relevant. At this point the fact that appellant had been administratively adjudged to be incompetent in Springfield after conviction is not controlling. The accused in a section 4244 hearing (before trial) is also “prima facie” incompetent since that hearing is not held until a court-appointed psychiatrist reports the accused is mentally incompetent to proceed with the trial. And yet, section 4244 comprehends that the accused is to testify at the hearing. The House Report declares: “The accused’s rights are protected by the added provision that his (or her) statements at such hearings shall not be admitted in evidence at any subsequent criminal proceeding.”21 (Emphasis added.) Appellant did not lose those rights by being cross-examined. There is nothing in section 4244 which indicates a congressional intent to limit a defendant’s testimony to direct examination, and there is no rational basis for such a limitation.22
The suggestion that the United States Attorney’s office does not make it a practice to challenge the psychiatric report issued in the section 4244 procedure simply tends to show that where that officer possesses no information indicating the accused is competent to stand trial he does not attack the report.23 Certainly such inaction in one case does not constitute a waiver of the right to make a formal appearance in another nor does it indicate a congressional intent that the psychiatric opinion is not subject to attack by the prosecutor. In *637any event, while section 4245 may not require the presence of a United States Attorney or require an adversary-type proceeding in every case, the fact that the trial judges allowed the Government to intervene neither invalidates the findings nor raises a doubtful question of statutory interpretation.
Judge Bazelon suggests that the United States Attorney, being a subordinate of the Attorney General who has in effect (through the Prison Director) certified substantial doubt exists about Fooks’ competence when tried, should be prohibited from challenging or resisting the act of his superiors. The fact that the United States Attorney is a subordinate of the Attorney General who, by statute, is charged with the duty of transmitting the Prison Director’s certificate to the District Court is of no moment. The action of the Attorney General in forwarding the certificate and doctors’ reports is purely ministerial; it does not represent approval of the conclusions nor accord to the certificate a higher significance than the prima facie character given it by Congress. The Attorney General does not thereby repudiate the conviction or confess error. The action of the Attorney General is not a directive to the United States Attorney to refrain from challenging the report by withholding relevant evidence. Where the public interest dictates the United States Attorney’s controverting the statutory certificate and reports, the fact that the doctors and the United States Attorney are both technically subordinates of the Justice Department should not preclude intervention. The basic fallacy of a contrary view is suggested by the fact that the custodial supervision over federal penal institutions might have been entrusted to the Department of Health, Education and Welfare. It is only a coincidence that the Attorney General supervises for administrative purposes both the prosecutors and the custodians of convicted persons.
The record discloses substantial evidence to support the findings and this, in our view, precludes reversal. Whether this court would have reached the same conclusion is not the issue; this court properly limits its inquiry to the narrow question whether the trial judges’ finding was supported by substantial evidence. District judges, like appellate judges, may or may not be expert in psychiatry, but the former who collectively watched both appellant and the expert witnesses for many days are better able through our time-tested judicial process to reach a sound conclusion than are we on a cold record, however diligently we may search it out.
It is evident that the hearings below, far from impairing the legislative purpose, fully effectuated the intent of Congress and the procedural details and form of the hearings were within the broad latitude which must be allowed to trial courts. The essential thing, a fair hearing as a matter of substance, was achieved.
. The certificate issued by the Director of the Bureau of Prisons applied to all three convictions and thus, pursuant to 18 U.S.C. § 4245, each of the trial judges was required to hold a hearing. The hearing in case No. 13,000, however, was directed by an order of this court (dated March 11, 1955).
. Actually only two hearings wore held. A combined hearing was held by the two trial judges in cases 12,998 and 12,999, which consumed about five days of trial time. The subsequent hearing before the trial judge in case 13,000 lasted two and one-half days.
. Dr. Perretti examined appellant four times in 1953, i. e., April 19, April 26, May 5 and May 11. Appellant’s three trials resulted in convictions on April 22, June 11 and October 21 of 1953. Thus, appellant was examined shortly before and immediately after his first trial.
. It is of special significance that two of the District Judges, upon learning that medical experts who thought in 1954 that appellant was not competent to stand trial in 1953 had never examined the transcript of appellant’s testimony given at the trial, allowed Drs. Wilson and Pirkle to examine the transcripts during a hearing recess. Both doctors subsequently testified that it appeared from the testimony that appellant understood the nature of the proceedings during the period when he was being tried. Record, pp. 224-225, 240-242 (cases 12,998 and 12,999). Judge Bazelon’s memorandum does not deal with this aspect of the evidence.
. Judge Bazelon is correct in stating the opinion of the panel was “silent” on questions now urged as error. The reason is that these points were neither raised nor preserved at the hearings, nor argued on appeal. It is not the appellate function to search the record in order to answer every conceivable argument counsel might have raised if they had occurred to him or if he had considered them error.
. Section 4245 of 18 U.S.C. provides:
“Whenever the Director of the Bureau of Prisons shall certify that a person convicted of an offense against the United States has been examined by the board of examiners referred to in title 18, United States Code, section 4241, and that there is probable cause to believe that such person was mentally incompetent at the time of his trial, provided the ■issue of mental competency was not raised and determined before or during said trial, the Attorney General shall transmit the report of the board of examiners and the certificate of the Director of the Bureau of Prisons to the clerk of the district court wherein the conviction was had. Whereupon the court shall hold a hearing to determine the mental competency of the accused in accordance with the provisions of section 4244 above, and with all the powers therein granted. In such hearing the certificate of the Director of the Bureau of Prisons shall be prima facie evidence of the facts and conclusions certified therein. If the court shall find that the accused was mentally incompetent at the time of his trial, the court shall vacate the judgment of conviction and grant a new trial. Added Sept. 7, 1949, c. 535, § 1, 63 Stat. 686.”
. Section 4244 “formalizes the court procedure for accused persons whose mentality comes raider suspicion [before or during the trial] by providing for a psychiatric examination, report thereof to the court, hearing upon notice and a judicial finding.” H.R.Rep. No. 1819, 2 U.S.Code Cong.Service 1949, p. 1928.
. Record, p. 487 (cases 12,998 and 12,-999); p. 330 (case 13,000).
. At the earlier combined hearing appellant’s counsel indicated several times that he did not intend to offer the Springfield Report as evidence until after the Springfield psychiatrists had competed their testimony. On these occasions Judge Schweinhaut declared he would not admit the report. Record, pp. 115-116, 434—439 (cases 12,998 and 12,999). It is obvious the trial judge made this statement only because he felt the report could not be used to add to the testimony of the doctors who made the report. Thereafter, at the suggestion of Jrdge Keech, the substance of the report went into the record. Record, pp. 115-125. Both judges, however, received the report as evidence. Record, pp. 477—478. In the second hearing the Springfield Report was received when offered as evidence. Record, p. 109 (case 13,000).
. See, e. g., Record, pp. 119,135, 260-272, 360-368 (cases 12,998 and 12,999); Record, pp. 44r-45, 53, 104-108 (case 13,000).
. Record, pp. 5-6 (case 13,000).
At the first hearing, following the court’s refusal to vacate Fooks’ sentence prior to a judicial determination of incompetency, counsel declared: “If I may address the Court with respect to procedure, the statute is silent as to who is the moving party. I had reached that conclusion independently of consultation with Tour Honors, but I thought I better raise the point.” Judge Keech replied: “There has been no consultation, but I think it is proper for you to proceed.” Record, p. 7 (cases 12,998 and 12,999).
. Record, pp. 332-333, 362, 367 (ease 13,000); Record, pp. 496, 540 (cases 12,-998 and 12,999).
. Record, pp. 333-334 (case 13,000).
. Record, p. 3 (cases 12,098 and 12,999).
. There was an additional practical reason for permitting appellant to proceed as lie requested. The court, at appellant’s request, had subpoenaed the Springfield doctors who, after examining Fooks had reported him probably incompetent when tried. The doctors were directed to appear on the day the hearings began. Record, p. 370 (ease 13,000); Record, pp. 498, 499, 500 (cases 12,998 and .12,909). They were present as the hearing's commenced, ready to testify. It is logical that the Springfield psychiatrists should have been allowed to testify immediately and return to their work. Dr. Perretti, on the other hand, was available at St. Elizabeths at any time on a few minutes notice.
. Record, pp. 333, 362, 367 (case 13,000).
. Record, pp. 333-334 (case 13,000). It was appellant who made several motions requesting that these Springfield psychiatrists appear in person. Counsel urged that since Dr. Perretti would be present in person depositions from the Springfield doctors would not suffice:
“I think under those circumstances it is absolutely necessary that the other witnesses whose testimony from the record apparently will be diametrically opposed to his do appear in person and I suggest to your Honor that it is absolutely necessary that both of them come.”
. Record, pp. 118-125; 226-234 ; 236-238 ; 253-254; 259-265; 274 (cases 12,-998 and 12,999).
. See, e. g., Record, pp. 128, 133, 202, 242, 281, 289-290, 447, 451 (cases 12,-908 and 12,999).
. Record, p. 3 (eases 12,998 and 12,099).
. H.Rep. No. 1319, 2 U.S.Code Cong. Service 1949, p. 1928.
The dissenting statement would evidently have us believe that a defendant declared to be of unsound mind by psychiatrists before trial is not as prima facie incompetent as a prisoner certified by Prison authorities to be of unsound mind while serving a sentence. No basis for such distinction appears.
. There was nothing unfair in the cross-examination of Rooks. The examination in both hearings was very brief and confined almost exclusively to simple questions concerning appellant’s recollection of his trials, i. e., the charges, verdicts, sentences, names of judges, names of the complaining witnesses, etc.
. Moreover, there is certainly more reason for the United States Attorney’s office to enter an appearance in a 4245 hearing, such as the present one, which involves an individual convicted after a jury trial, than in the 4244 situation where the presumption of innocence remains in force. The stake of the public in the disposition and treatment of a-convicted criminal or felon then in a penal institution by due process warrants the Government’s intervention if for no-other reason than to insure that an otherwise valid conviction is not erroneously set aside on the untested conclusions of doctors who may or may not be aware of the legal aspects of the issues. Even after rigorous cross-examination in the fullest adversary sense the United States-Attorney might well conclude and concede that the prima facie certificate was correct.