dissenting. Although I continue to believe that our statutory law that requires a defendant to bear the burden of proving his insanity defense violates our state constitution; State v. Joyner, 225 Conn. 450, 483, 625 A.2d 791 (1993) (Berdon, J., dissenting); the defendant in this case has clearly proven by a preponderance of the evidence 1 that, due to mental disease *206or defect, he did not have the requisite mental capacity to be criminally liable for his actions. Solely on the basis of the facts recited by the majority, I would find that, as a matter of law, the defendant was legally insane. As Justice Felix Frankfurter once observed: “[T]here comes a point where this Court should not be ignorant as judges of what we know as men [and women].” Watts v. Indiana, 338 U.S. 49, 52, 69 S. Ct. 1347, 93 L. Ed. 1801 (1949).
In addition to the undisputed irrational conduct of the defendant prior to and during the attacks on the victim, which is set forth in the majority opinion, the trial court had before it the undisputed testimony of Walter Borden, a forensic psychiatrist, and Julia Ramos Grenier, a clinical psychologist. Borden clinically diagnosed the defendant as suffering from psychotic depression with a borderline personality disorder and depressive features. In other words, the defendant was diagnosed as being a “very confused [and] disturbed person who has poor behavioral controls and [who] tends to be vulnerable to periods of psychosis, [i.e.,] periods of explosive behavior.” Borden indicated that the defendant’s messages on the 911 police emergency telephone line were further evidence that he “was experiencing an increasing loss of control, that he did not want to cause harm, [that] he did not want to harm [the victim], but that he was losing control and was being overwhelmed . . . .” That loss of control was, in part, precipitated by the victim being charged with risk of injury to the defendant’s minor child that resulted *207in the child being placed in the custody of the state department of children and families.
Indeed, the evidence indicated that the defendant repeatedly pleaded for help from the police before he killed the victim. Immediately prior to the incident, the defendant called 911 requesting Officer Juan A. Morales of the Hartford police department, with whom he had previously spoken, to intervene. The defendant desperately pleaded: “Because I need him. This girl came here right now and broke everything here and threw the milk, the window, the door and poured the milk — a whole gallon of milk. I don’t want to do anything. I was there yesterday. Remember I went yesterday? . . . Now she’s up front screwing up my life here. If something happens, you know what’s going on. . . . Please do something. ... I don’t want to do anything!”
Grenier also testified that the defendant was mentally ill and diagnosed him as suffering from several mental diseases and defects: organic mood syndrome, organic anxiety syndrome, polysubstance abuse and organic personality disorder, an explosive type. Grenier was convinced that the defendant’s loss of control was linked to brain impairment.
Confronted with the testimony of these two expert witnesses, the state chose not to present a scintilla of evidence in rebuttal. This tactic was employed probably because the state could not find a credible psychiatrist or psychologist to refute Borden’s and Grenier’s testimony. Rather, the state relied solely on cross-examination. Although cross-examination is a means by which expert testimony may be discredited, the majority points to nothing in the prosecutor’s cross-examination that would undermine the testimony of these prominent mental health professionals.2 In fact, the majority conve*208niently places its brief discussion of Grenier’s uncontroverted testimony relative to her diagnosis in a footnote.3 Furthermore, the majority emphasizes the fact that the defendant suffered from substance abuse, yet fails to mention that Borden opined that the defendant probably would have killed the victim that day, regardless of any drugs or alcohol he had ingested, because the defendant’s controls were overwhelmed even without the substance abuse. Finally, the trial court’s specific findings regarding the defendant’s intent underscore his insanity.4
Although the trier’s findings of fact are to be given deference, we cannot abdicate our responsibility to do justice. As stated by Chief Judge Jon O. Newman of the United States Second Circuit Court of Appeals, the province of the fact finder “is not a fortress that can never be entered [by an appellate court], nor is it a black box into which we dare not look.” J. Newman, “Beyond ‘Reasonable Doubt,’ ” 68 N.Y.U. L. Rev. 979, 1002 (1993). This court must consider, as a trial court does in reviewing a jury verdict, whether, based upon all our knowledge as human beings, the decision of the *209trier of fact is “clearly against the weight of the evidence . . . .” (Internal quotation marks omitted.) State v. Hammond, 221 Conn. 264, 268, 604 A.2d 793 (1992). If it is, that conviction must “be set aside even if the evidence was conflicting and there was direct evidence in favor of’ sustaining it. Palomba v. Gray, 208 Conn. 21, 24, 543 A.2d 1331 (1988). In this case, there is overwhelming evidence that the defendant was unable to control himself due to mental disease or defect and that he was legally insane when he killed the victim.5
Accordingly, I dissent.
Even under General Statutes § 53a-12 (b), the defense of insanity need only be proven by a preponderance of the evidence (“[w]hen a defense declared to be an affirmative defense is raised at a trial, the defendant shall have the burden of establishing such defense by a preponderance of the *206evidence”). As a reminder, proof by a preponderance of the evidence is satisfied if the evidence, considered fairly and impartially, induces in the mind of the trier a reasonable belief that it is “more probable than otherwise” that the issue or fact is true. Busker v. United Illuminating Co., 156 Conn. 456, 458, 242 A.2d 708 (1968). “It [is] not necessary that the . . . proof . . . negate all possible circumstances . . . [n]or [is] it necessary that the proof rise to that degree of certainty which excludes every reasonable conclusion . . . .” Terminal Taxi Co. v. Flynn, 156 Conn. 313, 318, 240 A.2d 881 (1968).
The majority seems to place some importance on the fact that Borden, in a report he had prepared in 1982 for the defendant’s trial for the murder of his brother and sister-in-law, did not indicate that the defendant had *208experienced auditory or visual hallucinations. I fail to appreciate, nor does the majority discuss, the importance of this omission.
See footnote 11 of the majority opinion.
The panel of judges found the following: “Corroborative of this intent, as evidenced in a portion of the record, is the following: one, the threats to kill Adelaida Ramos made by the defendant to the victim’s mother three weeks prior to [the victim’s] death; two, the defendant’s pronouncement to the victim moments before her death that it is time for you to die; three, the defendant’s threatening remarks to a bystander witness if he interfered; four, the cuffing of the machete in an effort to hide it as he approached the victim; five, striking the victim four or five times with the machete and returning to her as she sat to cry for help, holding the hair of her head in his left hand and methodically applying the lethal blows with his right hand; six, after the killing the defendant returned to his apartment, upon seeing Police Officer Daniel Albert approach the rear door of his dwelling he slammed and bolted the door; seven, acknowledging to the Police while being transported to the Police Station that ‘I killed that fucking bitch, I killed her with the machete because she took my children away from me.’ ”
At the very least, the facts of this case indicate that the defendant acted under extreme emotional disturbance and should have been convicted of manslaughter in the first degree; General Statutes § 53a-55; instead of murder. General Statutes § 53a-54a.