A mug shot or mugshot (an informal term for police photograph or booking photograph) is a photographic portrait typically taken after a person is arrested. The original purpose of the mug shot was to allow law enforcement to have a photographic record of an arrested individual to allow for identification purposes by victims, the public and investigators. However, in the United States entrepreneurs have recently begun to exploit the mug shot for commercial gains via the mug shot publishing industry.
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 stark and simple, to avoid distraction from the facial image (as distinguished from a casual snapshot in a more naturalistic setting). 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.
The earliest photos of prisoners taken for use by law enforcement may have been taken in Belgium in 1843 and 1844. In the United Kingdom, police in Liverpool and Birmingham were photographing criminals by 1848. By 1857, the New York City police department had a gallery where daguerreotypes of criminals were displayed.
The Pinkerton National Detective Agency began using these on wanted posters in the United States. By the 1870s the agency had amassed the largest collection of mug shots in the U.S.
The paired arrangement may have been inspired by the 1865 prison portraits taken by Alexander Gardner of accused conspirators in the Lincoln assassination trial, though Gardner's photographs were full-body portraits with only the heads turned for the profile shots.