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  • Writer's pictureJustin Sparks

What Is the M'Naghten Rule in Texas? | Full Overview

There are rules and tests used to support an insanity defense. Every state uses several of these tests to evaluate if someone was mentally sound at the time of committing a crime.

The M'Naghten rule has been used since 1843. It's based on an old case involving Daniel M'Naghten. He got a "guilty but insane verdict" after he shot and killed the British Prime Minister's secretary.

Texas mostly works with the M'Naghten rule for insanity defense cases. It also works with the irresistible impulse test. The state places the burden of proof on the defendant, so interested people should read this page to understand how this rule affects an insanity defense claim.

About the M'Naghten Rule

About the M'Naghten Rule

The M'Naghten rule applies to defendants who couldn't tell the difference between right and wrong at the time of the criminal act. These people argue that their mental defect prevented them from understanding what they did was wrong.

Defendants must prove beyond reasonable doubt that their mental illness affected their cognitive awareness, which led to the crime. According to the Texas Penal Code (Section 8.01), this is an "affirmative defense."

Another test used in Texas is the irresistible impulse one. The defendant argues that, due to a severe mental disease, they weren't able to control their impulses, resulting in their criminal act.

It's hard to prove insanity even with the help of a criminal defense attorney in Fort Worth. Criminal law tends to have different policies depending on the state, which makes the system inconsistent. Many people argue that some defendants put up a fake insanity defense claim to get a lighter sentence.

There are also many variables to consider before getting an insanity verdict. The Andrea Yates case is an example of how complex and delicate this defense strategy is. She drowned her children under the argument that she was saving them from Satan. Andrea was diagnosed with schizophrenia and other disorders.

She was found not guilty by reason of insanity in 2006. People can argue that she couldn't tell right from wrong due to her several mental conditions. This applies under the M'Naghten rule.

However, Andrea's acquittal was denied at first. This is because she immediately called the police after drowning her children, which suggested she did know right from wrong.

These variables are what make the system around the insanity defense so inconsistent, which is why it's hard to navigate these cases.

How Does the M'Naghten Rule Compare to the Other Tests?

The M'Naghten rule is the most used one in the country alongside the "Model Penal Code Test." There are two more rules/tests besides the ones mentioned:

  • Model Penal Code Test: The defendant had a mental disease that prevented them from understanding the severity of their act or acting lawfully.

  • Durham Rule: This rule is only applied in New Hampshire. It argues that the defendant's mental defect was responsible for the criminal act.

Texas law uses the M'Naghten rule and the irresistible impulse test to determine if someone was mentally sound at the time of committing a criminal offense or if they had criminal intent.

What Does the Defendant Have to Prove in an Insanity Defense?

First, the defendant must prove they were diagnosed with a valid mental illness or defect. Most of the time, the person will get evaluated by an appointed expert. Then, the defendant must notify that they want to use an insanity defense plea at least 20 days before the trial.

If the defendant shows convincing evidence to support their claim, they may get acquitted. This is a legal requirement according to the Insanity Defense Reform Act, which was signed in 1984 after John Hinckley was found not guilty by reason of insanity for trying to kill President Ronald Reagan.

Courts will first evaluate if the defendant can stand trial. If they're deemed incompetent, they could still be convicted. People who get deemed incompetent to stand trial will be committed to a mental hospital, outpatient treatment program, or other related facility until they can go to court.

Incompetency cases are different from insanity ones. Someone who successfully claims insanity will get acquitted of their charges. Those who get deemed incompetent to stand trial won't necessarily get acquitted.

What Happens If the Defendant Proves They're Insane?

Even though the defendant will get acquitted of their charges if they're successful with their insanity defense, they won't get released. Texas courts may establish different outcomes depending on whether the person committed a violent act or not and if they're considered dangerous. Contact Spark Law for more information on questions like What happens if you plead insanity in Texas?

Usually, the person will get committed to a mental health facility until they're not considered a danger to themself or others anymore. According to the Texas Code of Criminal Procedure (Title 1, Chapter 46C, Subchapter A), a defendant acquitted by reason of insanity can't get committed to a mental health facility for longer than the maximum prison sentence for the offense.

In other words, a defendant can be committed for the same time they would have otherwise spent in jail. Sometimes, however, the person may get an extension on their commitment period if they're still deemed dangerous.

Why the Insanity Defense Isn't Always Successful

Why the Insanity Defense Isn't Always Successful

Insanity defenses are used in less than 1% of court cases in the U.S. The success rates for these cases are also low.

These cases are complex due to all the variables to consider. Cases involving jurors are even more challenging since those people find it hard to believe that someone wasn't mentally sound when they committed the crime.

The only way to have a solid case is to work with a reputable criminal defense attorney and gather the right evidence. Even if the person gets a report from a mental health expert supporting their insanity claims, they're not guaranteed to get a not-guilty verdict.

Bottom Line

The M'Naghten test is one out of four different measures used to evaluate if someone is innocent or guilty under "insanity" cases. People who want to use this defense strategy must be aware of all the possible outcomes before taking action. It's not uncommon for NGRI defendants to withdraw their plea after the state finds them to be legally sane, for example. Sparks Law Firm can advise on what insanity test is used in Texas.

These cases are rare because the success rate is considerably low. Still, it's important to learn about these strategies just in case a person (or their loved one) is going through similar circumstances.

People interested in knowing more about Texas law should seek a consultation with the Sparks Law Firm.


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