These records represent two distinct eras of law enforcement in Santa Cruz county. They fall into four distinct categories: Warrant Registers (1931-1959), Prisoners' Time Books (1909-1945), "Mug" Books (1923-1957), and Forensic Photos (undated, but chiefly from the 1930s and 1940s). The first class of records constitutes a basic listing of all individuals arrested and charged with a crime. The "Time" books name and describe the comings and goings the prison population. The Mug Books are a visual record of those arrested, while the Forensic Photos consitute a visual record of the scenes and victims of some of their crimes during the period indicated.

Santa Cruz County was one of the original political subdivisions of the state of California. The first county jail,however, was not built until 1854. A stone jail replaced the original frame structure in 1864. This building contained four cells without windows. It was replaced by a third structure in 1890. This building stood on the site of the present county jail and was in use until 1936, when the WPA erected the current structure.

Collection is open for research.