The diagnosis is often made using clinical criteria.

There aren't usually lab tests or any kind of measures that will identify somebody with a mental illness it's often a family member or they've had an encounter with

somebody in law enforcement or something unusual happens that brings them to the attention of the medical community.

He was wounded.

He is in stable condition that the president was hit.

John Hinkley, Jr.

This letter is being written an hour before I leave for the Hilton Hotel.

Jody, I'm asking you to please look into your heart

and at least give me the chance with this historical deed

to gain your respect and love.

Mark Chapman.

According to police sources, the man had been seen at the apartment house earlier,

and later in the evening when Lenin arrived,

the man appeared to be rational.

He called out Lenin's name, then crouched police style, and fired.

Defendant Jeffrey Dahmer interposes a plea of not guilty and not guilty by reason of mental disease or defect.

And Rea Yates.

Because at least 10 jurors have a reasonable doubt

as to the probability the defendant would commit criminal acts of violence

that would constitute a continuing threat to society,

determined that the answer to special issue number one is no.

The malicious wounding trial of Lorena Bobbitt

...