On this day in 1851, an angry mob in San Francisco's business district "tries" two Australian suspects in the robbery and assault of C. J. Jansen. When the makeshift jury deadlocked, the suspects were returned to law enforcement officials. Jansen was working at his store at the corner of Montgomery and Washington when two men beat him unconscious and stole $2,000. Another merchant, William Coleman, then decided to play prosecutor and assembled judges and jury members from a crowd that had assembled at Portsmouth Square. Fortunately for the Australian suspects, the men who defended them got three jury members to agree that Jansen hadn't been able to see the men who had robbed him clearly. Although some members of the mob wanted to hang the alleged thieves in spite of the verdict, the crowd dispersed. Later, however, local authorities convicted the men at a real trial in court.
Vigilantes were fairly common during the Gold Rush boom in San Francisco. One committee spent most of its time rooting out Australian ne'er-do-wells. They hanged four and tossed another 30 out of town. In 1856, a 6,000-member vigilante group was assembled after a couple of high-profile shooting incidents. This lynch mob hanged the suspects and then directed their attention to politics.
Such vigilante movements were generally popular all over the West in the middle and late 19th century. The San Francisco vigilantes were so well regarded that they took over the Democratic Party in the late 1850s and some became respected politicians.