Does Mental Illness Affect Violent Crime Cases?


The insanity defense – if there is one legal maneuver that everyone knows, it is the insanity defense. This is kind of baffling considering the insanity defense is very rarely utilized. However, while not always “insanity,” mental illness does play a large part in the criminal justice system.

Mental illness is usually that topic that people don’t like to talk about. However, it appears frequently in the courtroom. Mental illness can cause people to act impulsively, recklessly, and even violently. However, how does a person’s mental capacity affect their criminal defense?


Forget the insanity defense. It is difficult to prove insanity in Minnesota, and even so, very few cases fit the narrow scope in which the defense can apply. However, when it comes to mental health, there are three defenses in which it can work in your favor to protect you from a violent crime conviction.


The insanity defense focuses on a person’s mental state at the time of the crime only. However, the competency defense focuses on the mental state of the accused in the present. You cannot stand trial if you cannot understand that you are being tried for a crime or are not able to assist in your own defense.

If someone were to, for example, be lost in their own delusions at their trial date, they will be found incompetent. The trial will then halt until the person can seek treatment and return to competency. For those truly ill, this assures they still see justice despite being mentally ill.


This is actually rather similar to the insanity defense, but it falls under a broader scope so it can be used more often. Like the insanity defense, the criminal responsibility focuses on the mental state of the accused at the time of the crime. As an affirmative defense, it must be raised by your lawyer in pretrial proceedings. For this defense, you cannot be found guilty because your mental state did not allow you to realize you were committing a crime at the time. This means the case becomes less about proving that you did not do it, but rather that you could not comprehend your actions.

If you are found not guilty by reason of criminal responsibility, then a secondary hearing will take place. This will decide if the party can be treated and if they are a danger to society. In terms of violent crime charges, most often the accused will be committed and accessed again at a later date. For very violent crimes, such as some mass shootings, the accused may very well be committed indefinitely.


This mental illness defense is usually used when there is a very strong case against you. Instead of arguing a likely fruitless defense that you are not guilty via criminal responsibility, your lawyer will argue that you have diminished culpability due to your mental illness. This will usually net you a lesser charge.

For example, if you knowingly murdered someone, it would be a homicide charge. However, if you unknowingly murdered someone, it is considered a lesser charge of negligent homicide that has a lesser punishment. So, if a prosecutor can prove that you knew murder was a crime, but you were not completely aware of your actions, this defense can limit your punishment.


Mental illness is so often swept under the carpet, and a lot of people swept under the carpet end up in prison when they really should not be there. If you or a loved one has been arrested for a violent crime, but their mental illness may have affected their capacity to commit that violent crime, contact us today. The Speas Law Firm is dedicated to representing everyone that needs help so they aren’t saddled with unfair punishments.