I am currently designing and setting up a new exhibit at the Gibson Museum. One half is about the notorious highwayman/outlaw Buck English. He was tried in Lake County multiple times for assault and grand larceny. He was a serial livestock thief.
The Courthouse Museum has multiple sets of his trial documents, dating from 1876-1877. He was eventually sentenced to life in prison for robbing a stagecoach near the Napa/Lake County line, and released on parole in 1912.
This particular affidavit from 1877, regarding the theft of an ox in 1876, shows his 'X' mark acting as his signature... Come check it out next week!