Nov 21, 2017

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How Does the Insanity Plea Work?


Hollywood can be considered largely responsible for the misconceptions with the insanity plea. Unlike in the movies, the insanity plea is slightly more complicated than it may appear. If an individual wishes to plead insanity, the defense must provide evidence illustrating the individual’s inability to distinguish what is wrong and what is right.

What is an Insanity Plea?

The insanity plea may be used by the defense in a criminal trial to avoid pleading guilty.  Generally, the insanity plea is used when the defendant has committed a crime and feels they will be found guilty by the end of the case. Though most states will recognize the insanity plea, there are some that do not: Kansas, Utah, Idaho,  and Montana. The main reason a defendant will attempt to be considered mentally insane, is that if found so, the punishment for the crime may be less severe.

The defendant must be legitimately diagnosed to be considered mentally unstable. To be deemed mentally unstable, the diagnosis should reflect the defendant’s inability to practice sound judgement. A few conditions that may support the insanity plea:

  • Psychoses
  • Post Traumatic Stress Disorder
  • Depression
  • Traumatic Brain Injury

M’Naghten Rule

The most commonly utilized type of insanity defense is known as the M’Naghten test, sometimes referred to as the Right-Wrong Test.  This test employs  two principles to determine whether or not the defendant understood the crime was wrong while committing it. One of the principles assumes that the defendant is considered mentally stable unless proven otherwise. A criminal defense attorney may request the testimony of a medical professional, or perhaps another expert witness, in order support the claim that their client was insane. The other principle requires the defense to prove that the accused was unable to determine that the act committed was wrong. If the defendant is either considered insane, or the defendant did not know the crime was wrong, then the insanity plea might be successful.

The law can be convoluted and difficult to navigate. It is recommended to seek the counsel of a criminal defense attorney such as the Criminal Lawyer Peoria IL locals turn to. There are many details regarding a case that may determine whether or not the insanity defense will be effective. Sit down with a professional attorney and explain your case. It is imperative that your remain honest with your attorney and provide all details. The attorney will do their best in order to provide a favorable outcome for your case.

Thanks to authors at Smith & Weer, LLP for their insight into Criminal Defense Law.