An illustration of a criminal being held down for a mug shot at police headquarters during the anarchist trials (known as the Haymarket affair) in Chicago, Illinois. The Haymarket affair concerns a bombing that occurred at a labor demonstration in support of striking workers on May 4, 1886 at Haymarket Square in Chicago. An unidentified participant threw a dynamite bomb at police who were trying to break up the meeting, killing seven officers and four civilians, and wounding many others. Eight anarchists were convicted of conspiracy and four were hanged, even though none of them was accused of throwing the bomb. Photographing criminals caught on in the 1880s, after Alphonse Bertillon (1853-1914), a French police officer, invented the standard mug shot in: a pair of photographs (one frontal, one in profile) taken in similar lighting conditions and attached to ID cards recording other descriptive physical data. This image is from Frank Leslie's Illustrated Newspaper, July 31, 1886.