A mug shot or mugshot (an informal term for police photograph or booking photograph) is a photographic portrait of a person from the shoulders up, typically taken after a person is placed under arrest. The primary purpose of the mug shot is to allow law enforcement to have a photographic record of an arrested individual to allow for identification by victims, the public and investigators.

Photographing of criminals began in the 1840s only a few years after the invention of photography, but it was not until 1888 that French police officer Alphonse Bertillon standardized the process.

"Mug" is an English slang term for "face", dating from the 18th century. Mug shot can more loosely mean any small picture of a face used for any reason.

A typical mug shot is two-part, with one side-view photo, and one front-view. The background is usually plain to avoid distraction from the head. Mug shots may be compiled into a mug book in order to determine the identity of a criminal. In high-profile cases, mug shots may also be published in the mass media.

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