Disestablish the M’Naghten Rule

 

This bill will provide a pathway to disestablishing the M’Naghten rule as the standard for the determination of an

insanity defense. There will then be a new standard put into place, taking into greater account the level of violence in

the crime committed as well as the likeliness of recidivism. This new standard should come in either the form of a new

test with modern guidelines, such as the Moral Penal Code Test (MPC); or with an abolishment of the insanity defense as

a whole, with instead an emphasis on using mental health as a mitigating factor to Mens Rea.

 

The M’Naghten Rule dates back to mid 19th century England, and was already considered defunct in the state of New

Hampshire. The product of the M’Naghten Rule in Canada, where it is codified into national law, is a 17% recidivism rate

following a NGRI/GBMI ruling and subsequent release from a mental facility. Although not awful, recidivism in these

cases is significantly easier to spot - the rate should be lower than 10%. While US data is unreliable due to a lack of

research, individual cases of recidivism are proof enough. Gary Muehlberg, who was charged with rape and robbery of an

eighteen year old girl, was found NGRI due to the MNaghten’s non-consideration of violence. Two months after release, he

committed the same acts on a fourteen year old girl. Studies have shown that recidivism among those found NGRI/GBMI

impacts others at a much higher rate than those who do not receive such a ruling. M’Naghten contributes to this as it

forces the judicial system to give lesser sentences to violent criminals through it's non consideration of violence.

 

M’Naghten Rule - The current standard for certifying a plea of insanity. The exact language used in Minnesota is, “No

person having a mental illness or cognitive impairment so as to be incapable of understanding the proceedings or making

a defense shall be tried, sentenced, or punished for any crime; but the person shall not be excused from criminal

liability except upon proof that at the time of committing the alleged criminal act the person was laboring under such a

defect of reason, from one of these causes, as not to know the nature of the act, or that it was wrong.”(Minnesota

Statutes 2025, Section 611.026)

Moral Penal Code Test: A modernized insanity test from the American Legal Institute, fixing many of the issues found in

the M’Naghten rule.

Not Guilty By Reason of Insanity (NGRI): A finding that a defendant was not legally responsible for their actions due to

a mental illness at the time of the offense.

Guilty but Mentally Ill (GBMI): A finding for a defendant who is found guilty of a crime but also has a mental illness

that is not severe enough to meet the legal standard for insanity.

Recidivism: The tendency of a convicted criminal to reoffend.

Mens Rea: The intention or knowledge of wrongdoing that constitutes part of a crime, as opposed to the action or conduct

of the accused.

 

Funding for the bill will include staffing and other support for the working group in Section V, which will be derived

from attorney licensure fees paid to the state, not to exceed $30,000 per year.

 

A working group will be appointed to work through the logistical complexities of such a change. This working group will

be responsible for removing the test as standard, finding a new standard, and other actions deemed necessary and proper

for them to undertake. The members of this working group will be appointed by the governor and must include majority and

minority members of the Minnesota House of Representatives and Minnesota Senate, and members of the Judicial branch.

 

The working group will be appointed by the Governor no later than the start of the 2027 legislative session. Following

this, the working group will be expected to be done with their work by the start of the 2028 legislative session.

Courtroom reforms; training for public defenders, prosecutors, and judges; and jury education will be completed no later

than the first day of the year 2030.