A more thorough explanation:

The Model Penal Code is a set of guidelines for criminal law created by the American Law Institute. It presents a specific way of determining whether someone is legally insane at the time they committed a crime.

According to the Model Penal Code, a person is not responsible for their criminal actions if they had a mental disease or defect that prevented them from understanding that what they were doing was wrong, or from following the law.

For example, if someone with severe schizophrenia believed that they were being attacked by aliens and killed someone they thought was an alien, they might be able to use the insanity defense. This is because their mental illness prevented them from understanding that killing someone is wrong.

Another example might be someone with severe depression who attempted suicide by driving their car into a building. If they were unable to understand that this action was against the law, they might be able to use the insanity defense.

The Model Penal Code Insanity Defense is a way to ensure that people who are not capable of understanding the consequences of their actions are not held responsible for them. It is an important part of our legal system that helps to protect the rights of those who are mentally ill.