A policeman transporting a prisoner in a cage on the sidecar of his motorcycle, ca. 1920s. The traffic police of Los Angeles used these vehicles in order to capture and later transport drivers, who have violated the speed and parking rules, to the police station.
This “portable prison,” a singular jail cell measuring four-square-feet, attached to a police motorcycle as a sidecar to keep its occupant close enough to the officer to be able to grab the keys to let yourself out, plus you could probably reach the brakes.
(via forgottenmadness_la and Periscope)