A more thorough explanation:

Sleepwalking defense: A legal defense that asserts automatism, which is action or conduct occurring without will, purpose, or reasoned intention, such as sleepwalking. Automatism may be used to negate the requisite mental state of voluntariness for commission of a crime.

Example: John is sleepwalking and unknowingly walks out of his house, enters his neighbor's house, and takes a valuable item. If John is charged with theft, he may use the sleepwalking defense to argue that he did not have the requisite mental state to commit the crime because he was not conscious of his actions.

Ambulatory automatism: Automatism that consists of purposeless wanderings.

Example: Sarah is driving her car and suddenly enters a state of automatism, causing her to drive aimlessly without any purpose or awareness of her actions. If Sarah causes an accident during this state, she may use the defense of ambulatory automatism to argue that she was not conscious of her actions and therefore not responsible for the accident.

Overall, the sleepwalking defense is used to argue that the defendant did not have the necessary mental state to commit a crime due to their unconscious actions.