Photo crop exposure date: unknown.
Exposure date (or window) of subject photo: 1940’s
Subject: Police garage. A “pull over” light is being installed atop the right front fender of a marked car. The light was mounted at about 90 degrees to forward travel of the vehicle and so as to be easily seen as the police vehicle came alongside a driver. It would be operated manually by the officer and would often, in addition to being red, project wording such as POLICE or STOP or PULL OVER.