Defendant appeals from the denial, without a hearing, of his petition for a writ of habeas corpus. He was convicted in the Superior Court of Massachusetts of murder in the first degree by extreme atrocity and cruelty.1 The jury recommended that the death penalty not be imposed. The Supreme Judicial Court affirmed the conviction. Commonwealth v. Eisen, Mass., 267 N.E.2d 229 (1971).
At trial the evidence showed that Margot Eisen, defendant’s wife, died of a single axe blow to the head and that Gabrielle, his daughter, died of multiple blows to the head. Their bodies were discovered on the morning of November 4, 1966. Expert testimony placed the time of death between the evenings of *862November 2 and 3, or perhaps as early as the evening of November 1. Prior to the discovery of the bodies on November 4 the defendant was seen going into his house and leaving after a brief stay. On November 5 he approached two hunters in the Connecticut woods, saying “Help, help. Shoot me. I killed my wife and daughter. Call the police.” At that time he appeared nauseated and was wearing a red blanket over his head. The Connecticut State Police were called and when they arrived on the scene, defendant made further incriminating statements. He seemed very distraught, nervous, sick, appeared to have vomited and defecated on his clothing and was at times incoherent. He was taken into custody and on November 7 was committed to Bridgewater State Hospital where he was subsequently found incompetent to stand trial. More than a year later he was declared competent and his trial commenced in April 1968.
At trial one Marcia Reid testified that at about 11:30 on the morning of November 4 she received a telephone call from the defendant who said, “This is Karl,” and asked her to call the police. He did not sound excited or disturbed. Mrs. Reid then turned the telephone over to her husband, Kenneth, who testified over objection that the defendant told him “that he had done something terrible; that his wife and daughter were dead at home in Kingston, but he couldn’t go through with it with the other children. He had them locked in a motel room.” Over similar objection a Margaret Bernardo testified that on the same morning the defendant telephoned her and said that his wife and daughter had been dead at home for two days and that he was in Canada with three of the children. He asked, “What shall I do?”
Chief Goonan of the Kingston police stated over objection that on November 5 while in custody the defendant said to him and several other policemen, “I know I haven’t got to say anything, but I got to say this. How can you people be so nice to me after what I have done ?” 2 Somewhat similar incriminating statements made to other officers at the time of defendant’s arrest were admitted without objection. Detective Sanga of the Connecticut State Police testified that on Saturday, November 5, he was called to a state forest in Connecticut. There he asked the defendant if he was Karl Eisen who was wanted by the Massachusetts police authorities, and the defendant replied, “Yes I am, I did it, I did it, I did it.” Another State police officer who accompanied Detective Sanga testified to the same effect.
The defense was based on insanity. The defendant took the witness stand and stated as follows: on Wednesday, November 2, he did not eat all day; late in the evening he had two small glasses of cognac and a bottle of beer and a sip from a second bottle of beer; he did not feel well — was sick to his stomach; arrived home about 10 or 10:30 p. m.; felt miserable and went to bed. The ceiling seemed to be turning. During the night he heard somebody crying. He could not awaken his wife; she did not move. He went upstairs to his sons’ room and tucked them in bed. The next thing he remembered was awakening in broad daylight, kneeling by his son Dean’s bed. Then he went downstairs and saw that his wife was dead. He covered her face with a pillow, went upstairs and saw that his daughter was dead and placed a bureau in front of the door to her room. The defendant woke up his other children and drove off with them. His memory of the events between November 3 and 5 was very incomplete, and he maintained that he had no further recollection of the events of the night of November 2. Defendant’s medical expert testified that he was insane on the date of the crime.
*863At the close of the defendant’s direct testimony, his attorney moved to strike all inculpatory statements made by the defendant, oral or written. This motion was predicated on the testimony of the medical experts that the defendant was insane at the time these statements were made. The motion was denied.
In this petition two issues arise from defendant’s claim of insanity: whether his in-custody statements were voluntary and whether his noncustodial inculpatory statements were competent.3 A review of the expert testimony on defendant’s mental condition is a prerequisite to any consideration of these issues.
Dr. Mezer, defendant’s expert, testified:
“ [Defendant’s] psychotic-depressive reaction began some time between March 21, 1966, when Mr. Eisen’s wife took an overdose of barbiturates in a suicidal attempt. It was after that period of time; during the period of time when she was in the hospital.
“It was during this period of time that Mr. Eisen’s depression began, because he had to take care of the children, and wasn’t able to concentrate on his work; and the bills piled up. So, that’s really the beginning of the depression.”
Dr. Allen, the state’s medical expert, conceded that the defendant was insane and incompetent on November 7. Despite some initial reluctance to do so, he further stated that in his opinion the defendant was mentally ill and no longer rational on November 3.
Jackson v. Denno, 378 U.S. 368, 84 S.Ct. 1774, 12 L.Ed.2d 908 (1964) requires a trial court to rule that statements to police officers were voluntarily made before they are submitted to the jury. The court’s “conclusion that the confession is voluntary must appear from the record with unmistakable clarity.” Sims v. Georgia, 385 U.S. 538, 544, 87 S.Ct. 639, 643, 17 L.Ed.2d 593 (1967). There is substantial doubt in the instant case that the trial court applied a proper test in determining the voluntariness of custodial statements to police officers. The court appears to have used the same standard for all its rulings on the admissibility of defendant’s • inculpatory statements.4 While it considered it relevant that there were no threats, pressure, or suggestions by police officers, the court failed to take into account that the defendant’s insanity may have deprived him of his freedom of choice, the essence of his ability to make a voluntary *864confession. Blackburn v. Alabama, 361 U.S. 199, 80 S.Ct. 274, 4 L.Ed.2d 242 (1960). In ruling on the motion to strike, the court had before it substantial evidence of defendant’s insanity at the time of his custodial inculpatory statements. Yet neither in its ruling on this motion5 nor in its charge to the jury6 did the court appear to recognize that insanity relates to the issue of volition as well as to the issue of competence.
Commonwealth v. Zelenski, 287 Mass. 125, 191 N.E. 355 (1934), on which both the trial and the appellate courts relied, stands for the proposition that “it was for the jury to determine upon all the evidence whether ‘the mental infirmities of the defendant deprived him of the faculty of consciousness of the physical acts performed by him, of the power to retain them in his memory, and of the capacity to make a statement of those acts with reasonable accuracy. An insane person is not necessarily an incompetent witness.’ ” Commonwealth v. Eisen, supra (citation omitted). Competency, not voluntariness, was at issue in Zelenski. Thus a finding of voluntariness using a test for determining competency is not adequate because it does not take account of the possible absence of free will. In discussing whether a confession is the product of a man’s free will, the court said in Pea v. United States, 130 U.S.App.D.C. 410, 397 F.2d 627, aff’d on rehearing, 397 F.2d 627 (1968) (en banc):
“The make-up of a free man includes his mechanisms for self-preservation, to refrain from speech that may endanger him. If he does speak out his statement is admissible as the reflection of his free will if his self-preservation mechanism, and its impetus to silence, is overridden by pressures within his own personality, by his own conscience, religious feelings, sense of duty, etc. But his statement does not reflect his own free will or intellect if his statement is attributable in critical measure to the fact that his self-protective mechanism is negated or overridden by external force or fraud, a condition of insanity, the compulsion of drugs.” Id. at 634. (Emphasis added.)
Since it is clear that insanity may deprive a man of his ability to make a voluntary confession, Blackburn v. Ala*865bama, supra, the failure of the trial court here to clearly consider whether defendant’s confessions to the police officers subsequent to his arrest were the product of a rational intellect requires a reversal. In Blackburn the Court said:
“In the case at bar, the evidence indisputably establishes the strongest probability that Blackburn was insane and incompetent at the time he allegedly confessed. Surely in the present stage of our civilization a most basic sense of justice is affronted by the spectacle of incarcerating a human being upon the basis of a statement he made while insane; and this judgment can without difficulty be articulated in terms of the unreliability of the confession, the lack of rational choice of the* accused, or simply a strong conviction that our system of lawId., at 207, 80 S.Ct. at 280.
Although the foregoing disposes of this appeal, we nevertheless address ourselves to the issue of the defendant’s competency, i. e., his memory, at the time of his alleged noncustodial inculpatory statements. We do so because of the likelihood of their introduction at a new trial. It was conceded that the defendant was insane and incompetent to stand trial on November 7, and that he continued in that state for more than a year. The experts agreed that defendant had no memory of the events of the night of November 2 while at Bridgewater. The defendant’s expert testified that this state of memory loss dated back to November 3, and that such memory loss was consistent with his mental condition. While he acknowledged that it was possible that defendant’s memory was intact on November 3 and 4,7 he stated that it was likely that upon discovery of the bodies defendant assumed responsibility for the deaths even though he had no memory of the crime and might in fact be innocent. The evidence, viewed as a whole, indicates a strong probability that defendant’s admissions were the result of such an assumption or of an insane compulsion to confess and that they were not based on memory. Defendant’s objection to the admission of these statements raised an issue which should have been resolved by the trial court on grounds more substantial than the barest possibility that they might have been competent.8 In view of the nature and importance of defendant’s inculpatory statements and his prima facie claim of *866incompetence, we would look askance at their admission without reliable evidence indicating that they were in fact competent.
The judgment of the district court dismissing the petition is vacated. The case is remanded to the district court with instructions to grant the writ, unless, within a reasonable time set by the district court, the petitioner is retried by the Commonwealth.