We see it proposed in movies, television shows, and high-profile crime cases – the insanity defense. Although we might think of it often as consumers of media and entertainment, the reality of the insanity defense is that it is rarely used, and even less likely to be successfully argued by the defense counsel.
Legally Defining Insanity
Four tests are used to define insanity across the United States. In Minnesota, courts use the M’Naghten test. This rule emphasizes a defendant’s ‘knowledge’ or ‘knowingness’ that the act he or she committed was wrong.
Defendants are wary of entering an insanity plea because it shifts the burden of proof of insanity to the defense. The court and jury assume a defendant is sane until the defense proves otherwise. The assumption of sanity is backed up by the fact that people with mental health issues are no more likely to commit acts of violence than anyone else.
Further, defense attorneys must convince the court that their client is suffering from a diagnosed and curable mental illness. Defendants with personality disorders don’t qualify for the insanity defense because personality disorders can be diagnosed and treated, but they cannot be cured. Diagnosis and documentation of a mental illness are often a struggle for the defense too because fewer than half of adults with mental health problems receive the needed treatment.
Burden Of Proof Issues
The burden of proof of insanity is lower for defense attorneys than the burden of proof required by the prosecutor for a guilty verdict. To prove guilt, prosecutors must provide proof ‘beyond a reasonable doubt;’ that is to say near 100 percent likelihood that the defendant committed a crime.
For an insanity defense, defendants must prove insanity based on a preponderance of the evidence. That is to say, it is 51 percent likely, or more likely than not, that the defendant is insane. If defense attorneys can prove their client is likely insane, that opens the door for reasonable doubt.
This nuance creates two scenarios for those wishing to enter an insanity plea. Defendants can make a plea of “not guilty by reason of insanity” or “guilty but insane or mentally ill” both of which can result in the defendant’s commitment to a psychiatric facility.
Last Ditch Effort
The narrow definition of insanity in the state of Minnesota protects the public’s right to seek justice. Most criminal defense attorneys can have a lifelong legal career and never use the insanity defense. Instead, it is considered a last ditch effort for defendants who need access to treatment for a mental illness.