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Commonwealth v. ClancyInvestigation Archive • 2026
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Source: Plymouth Superior Court filing • Public record

Understanding Common Defenses to Criminal Charges

Despite popular perceptions to the contrary, defendants rarely enter pleas of "not guilty by reason of insanity." When they do, they often have a hard time proving it. The insanity defense is generally based on the principle that punishment is justified only where defendants are capable of controlli

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Understanding Common Defenses to Criminal Charges

Source: Nolo.com

URL: https://www.nolo.com/news/the-lindsay-clancy-trial-understanding-the-postpartum-psychosis-defense.html

Status: Original article blocked by Cloudflare protection - content below is from Nolo's general insanity defense coverage

The Insanity Defense

Despite popular perceptions to the contrary, defendants rarely enter pleas of "not guilty by reason of insanity." When they do, they often have a hard time proving it. The insanity defense is generally based on the principle that punishment is justified only where defendants are capable of controlling their behavior and understanding that what they've done is wrong.

Key Points

  • The insanity defense prevents some people who can't function fully from being criminally punished
  • Various definitions of insanity are in use because neither the legal system nor mental health professionals can agree on a single meaning
  • The most popular definition is the M'Naghten rule, which defines insanity as the inability to distinguish right from wrong
  • Another common test is irresirable impulse, which applies to someone who may know an act is wrong but because of mental illness cannot resist committing it

    • Outcomes

  • Defendants found not guilty by reason of insanity are not automatically set free
  • They are usually confined to mental institutions
  • These defendants can spend more time in a mental institution than they would have spent in prison had they been convicted

    • Expert Testimony

  • An insanity defense normally rests largely on psychiatrists or psychologists who testify after examining the defendant, their history, and the facts of the case
  • Courts appoint mental health professionals at government expense to assist poor defendants who cannot afford to hire their own

    • Related to Postpartum Psychosis

    The Lindsay Clancy case involves postpartum psychosis as the basis for the insanity defense. Postpartum psychosis is a rare, severe psychiatric emergency affecting approximately 1-2 per 1,000 births that can involve hallucinations, delusions, and loss of touch with reality.