A more thorough explanation:

Definition: A mug shot is a photograph of a person's face taken after they have been arrested and booked.

Example: When a person is arrested, the police take a picture of their face from the front and the side. This is called a mug shot. The mug shot is then kept in the police records and can be used as evidence in court.

Explanation: Mug shots are taken to identify people who have been arrested and to keep a record of their physical appearance. They are also used to help police officers and investigators identify suspects in other crimes. Mug shots are an important tool in law enforcement and can help solve crimes and keep communities safe.