A man who killed 10 people at a Colorado supermarket has been found guilty of murder in the 2021 attack, becoming the latest person to fail in an attempt to be acquitted by reason of insanity.

Jurors found Ahmad Alissa guilty on Monday, meaning he will be sentenced to life in prison instead of remaining in a state hospital for psychiatric treatment.

Suspects who claim insanity don’t usually succeed before juries in the U.S. Other examples include James Holmes, who killed 12 people at a Denver-area movie theater in 2012 and is serving life in prison.

It has become harder to succeed with an insanity defense since a federal jury found John Hinckley Jr. not guilty by reason of insanity for shooting President Ronald Reagan in 1981. The verdict stoked public skepticism about insanity pleas, leading to tougher federal and state requirements to reach acquittals, according to Christopher Slobogin, professor of law and psychiatry at Vanderbilt University.

Insanity defenses are successful in about 25% of cases that reach trial, Slobogin said. They are much more common in agreements with prosecutors before trial. Nearly seven in 10 insanity acquittals occur in plea deals, he said.

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The purpose of the insanity defense is to create room for a jury to decide that the crime happened because a person was fighting against bizarre thoughts but ultimately couldn’t control them and had a break, Slobogin said.

But that can be a difficult sell for a defense attorney, and few sane people get away with insanity defenses, Slobogin said.

“Laypeople are pretty skeptical of claims of mental illness. And mental health professionals are trained to detect malingering and often do so. So it’s unlikely there are very many invalid insanity acquittals,” Slobogin said.

After the Hinckley verdict, Congress and 11 states raised the bar for insanity convictions. Idaho, Kansas, Montana and Utah abolished it, Slobogin said.

In 2020, the U.S. Supreme Court ruled that states could prevent defendants from pleading insanity without violating their constitutional rights.

Here’s how insanity defenses played out in some notable cases:

Reagan shooter’s acquittal by reason of insanity changes public perceptions

Hinckley spent decades in a mental hospital after being found not guilty by reason of insanity in the shooting of Reagan and others outside a Washington hotel in 1981. Hinckley wanted to shoot the president because he thought it would impress the actress Jodie Foster. Released to live with his mother in 2016 and then on his own in 2021, he was freed from court oversight in 2022. Hinckley’s acquittal increased public skepticism about the insanity defense.

Insanity plea succeeds at retrial for mother who drowned her kids

A jury found Andrea Yates guilty of murder, rejecting the claim that she was so psychotic she thought she was saving their souls when she drowned her five young children in a bathtub in Texas in 2001. But an appeals court overturned her conviction due to erroneous testimony by a witness, and a jury at retrial found her not guilty by reason of insanity. She was sent to a state mental hospital.

Jury swiftly rejects newsroom gunman’s insanity claim

Jurors needed less than two hours in 2021 to find Jarrod Ramos criminally responsible for shooting five people to death in the Capital Gazette newsroom in Annapolis, Maryland, three years earlier. Ramos, who had a long-running grudge against the newspaper, pleaded guilty but not criminally responsible, which is Maryland’s version of an insanity plea. His attorneys argued he suffered from a delusional disorder as well as autism and obsessive-compulsive disorder. A judge sentenced him to five life terms plus additional time in prison.

Colorado movie theater gunman’s psychotic break claim doesn’t sway jurors

A jury rejected Holmes’ insanity defense for shooting 12 people to death and injuring 70 others in a Denver-area movie theater in 2012. Holmes’ attorneys argued he suffered from schizophrenia that led to a psychotic break and delusions, but prosecutors successfully argued that Holmes methodically planned the attack. Jurors did not reach a unanimous verdict on each murder count, however, resulting in a life sentence in prison instead of the death penalty.