M’Naghten rule

The M’Naghten rule is the legal test for criminal responsibility that governs the insanity arguments in In Cold Blood. It asks whether an accused knew the nature of the act and knew that it was wrong; it does not treat mental illness by itself as a defense when those capacities are present. The book shows the rule operating as both a courtroom standard and a limit on what psychiatric evidence can accomplish: clinical complexity may be raised, but the legal question remains tightly bounded.

The Rule and Its Legal Test

In the account of Kansas law, the M’Naghten rule is an established test under which an accused is mentally competent and responsible if he understood the nature of his act and knew it was wrong. The measure concerns legal, rather than moral, knowledge. It therefore does not ask simply whether a person had a diagnosis, behaved abnormally, or felt remorse. Its decisive issue is whether the person could distinguish right from wrong in the legally relevant sense.

That narrow focus becomes important because the defense and prosecution attach different significance to psychiatric expertise. In the proceedings concerning Perry Smith and Dick, defense counsel argues that trained examiners are needed to assess the accused, while the prosecution maintains that the governing law does not require specialists. The disagreement is not only about where the prisoners should be examined; it concerns what kinds of knowledge the court will recognize when deciding whether they are responsible.

The Dispute Over Examination in the Clutter Case

Soon after the original arraignment of Smith and Dick, their attorneys asked Judge Tate to send them to the state hospital in Larned for comprehensive psychiatric examinations. The proposed examinations were meant to determine whether either man was unable to understand his position or assist in his defense. Harrison Smith told the court that Larned was the only nearby institution with qualified psychiatric staff, that a serious evaluation would take four to eight weeks, and that the state hospital was willing to begin promptly without charging the county.

Logan Green, the special assistant prosecuting attorney, opposed the proposal. He anticipated that the defense would rely on temporary insanity and argued that Kansas law required no particular specialist: general practitioners could assess whether a person was insane, an imbecile, or an idiot. He also maintained that local physicians routinely handled such determinations and that transferring the prisoners to Larned would waste time. His position treated the legal test as a question that local medical judgment could answer without a specialized psychiatric inquiry.

Harrison Smith countered that the stakes made this unlike an ordinary probate-court sanity hearing: two lives were at issue, and the defendants deserved examination by people with relevant training and experience. He urged the court to take account of psychiatry’s development and the growing attention of federal courts to mental science in criminal cases. Judge Tate did not grant the requested examinations at Larned. Instead, he appointed a commission of three Garden City doctors, as the law required. After meeting the defendants for about an hour, the doctors reported that neither had a mental disorder. The ruling provided an assessment, but not the extended specialist examination the defense had sought.

What the Legal Question Excluded

The trial testimony concerning Dick makes the rule’s narrowing effect especially plain. Dr. W. Mitchell Jones was asked for his opinion and answered that, within the usual definitions, Dick knew right from wrong. The prosecution objected when the defense tried to have him qualify that answer. The court sustained the objection because Kansas law allowed no more than a yes-or-no response to the pertinent question, and the witness was dismissed.

The fuller assessment that Dr. Jones would have offered was more complicated than that permitted answer. Dick was described as intelligent, alert, organized in his thinking, and in contact with reality. At the same time, a serious head injury with concussion and several hours of unconsciousness in 1950 had been verified in hospital records. He reported subsequent blackouts, periods of amnesia, and headaches, but had never undergone the tests that could establish or rule out residual brain damage. Dr. Jones also identified emotional abnormality and impulsivity, including a tendency to act without considering later consequences. Those details did not alter the narrow answer the court allowed on legal sanity. The episode shows how the rule could make relevant clinical distinctions difficult to place before a jury, even when an expert considered further evaluation necessary.

The Andrews Case and the Challenge to Kansas Law

The later case of Lowell Lee Andrews presented a more direct challenge to the rule. Before Andrews’s trial, psychiatrists at the Menninger Clinic diagnosed schizophrenia, simple type. Their description distinguished the condition from delusions, false perceptions, and hallucinations; they characterized it instead as a separation between thinking and feeling. Andrews understood what he had done and that it was prohibited, but the clinicians saw his emotional detachment as central to his condition.

Dr. Joseph Satten and his colleagues believed the case offered an unusually strong basis for challenging the M’Naghten rule. Andrews’s defenders, including Menninger Clinic psychiatrists and two attorneys, sought to replace it with the Durham Rule, under which an accused would not be criminally responsible if an unlawful act resulted from mental disease or defect. If the court had adopted that standard, the defense expected Andrews’s diagnosis and the other evidence of his condition to support confinement in a hospital for the criminally insane rather than execution or imprisonment.

The defense did not prevail. Reverend Virto C. Dameron, Andrews’s former religious counselor, testified for the prosecution about warning him of divine judgment. His testimony, together with Andrews’s confession, helped settle the case. The judge upheld the M’Naghten rule, and the jury imposed the death penalty. The result demonstrates that the proposed alternative did not displace the prevailing legal test in this case, despite the psychiatric evidence and the defense’s effort to make the trial a broader test of criminal responsibility.

Narrative Significance

Across the two cases, the rule separates a person’s mental condition from the legal capacity that determines responsibility. In Smith and Dick’s proceedings, the dispute concerns access to specialist assessment and the narrow form in which expert testimony may be given. In Andrews’s case, the diagnosis is more fully described, and the defense explicitly seeks a different legal standard; nevertheless, the existing rule remains in force. The contrast makes the rule’s practical power visible: it structures which questions the court asks, which expert explanations can be heard, and what outcomes remain legally available.