A more thorough explanation:

Definition: Insanity defense and diminished capacity are legal concepts used in criminal cases to determine a defendant's mental state at the time of the crime.

Insanity Defense: This defense argues that the defendant was not responsible for their actions because they were suffering from a mental illness or defect at the time of the crime. If successful, the defendant may be found "not guilty by reason of insanity" and may be sent to a mental health facility instead of prison.

Diminished Capacity: This defense argues that the defendant's mental state at the time of the crime prevented them from forming the intent required for the crime. This defense does not result in a "not guilty" verdict, but may result in a lesser charge or sentence.

Examples:

• The Hinckley case: John Hinckley Jr. attempted to assassinate President Reagan in 1981 and was found not guilty by reason of insanity.
• Colin Ferguson - The Long Island Railroad gunman: Colin Ferguson killed six people and injured 19 others on a train in 1993. He used the diminished capacity defense, but was found guilty of murder and sentenced to life in prison.

These examples illustrate how the insanity defense and diminished capacity can be used in criminal cases to determine a defendant's mental state and responsibility for their actions.

Related Legal Issues:

• The law of evidence: admissibility of evidence
• Competence to Stand Trial
• Supreme Court cases on the insanity defense and diminished capacity

More Resources:

• Federal Insanity Defense Reform Act of 1984 (IDRA)
• Criminal procedure
• Criminal law
• Mental Health