September 2002
Among the New Orleans Police Department records deposited in the City Archives are several thousand mug shots of individuals arrested in the city ca. 1900 to 1925. The NOPD records also include some 700 "Bertillon cards" and several thousand glass negatives used to create mug shots.
The use of mug shots to aid in criminal identification became common practice in the late 19th century. Police departments, both in the United States and abroad, began to develop "rouges galleries" and to gather information about the perpetrators to accompany the photographs. In the early 1880s, French criminologist Alphonse Bertillon systematized and expanded the "science" of using photographs for identication purposes. "Bertillonage," in addition to photographing suspects (front and right profile shots), involved the gathering of precise physical measurements (height, weight, size of head, length of forearm, torso, ear, feet, etc.) and description (of scars, moles, tattoos). Although the Bertillon method was widely used, it was supplanted eventually by fingerprinting -- a much more precise and unambiguous method of identification.

Financial statements in the NOPD annual reports list expenditures for "photographs of prisoners" as early as 1894, and subsequent reports refer to the "Rogues Gallery" and the department's effort to update and maintain it. The force adopted the Bertillon system on December 8, 1896. Copies of the Bertillon cards were sent to the National Bureau of Identification (the forerunner of the FBI) in Chicago (later, in Washington D.C.) and to police departments around the country. The 1899 Annual Report notes that the combined system of Rogues Gallery and Bertillon cards "has been of the greatest value to this department, as many offenders were arrested and identified by this positive and thorough method. . . ." The system was relatively short lived, however; although the collection includes mug shots taken in the 1920s, the Bertillon cards stop ca. 1919.

We should note, of course, that the prisoners who were photographed were not necessarily tried and convicted of the crimes they are accused of.

Source: http://nutrias.org/~nopl/monthly/sept2002/sept02.htm