Biographical Information
Woodruff was an officer for the San Francisco Police Department stationed in Chinatown. According to an article in the San Francisco Alta, December 7, 1874, noting his resignation from the force: "His specialty was looking after Chinese thieves, in which he was most successful, and indeed he was looked upon as the head and front of the Chinese specials whenever any important duty was to be performed in that branch of the police service."
From the guide to the Photograph album of Chinese criminals, circa 1872, (California Historical Society)