Arthur Lupp of Highland Park founded the Michigan branch of the Black Legion in 1931; it was a secret vigilante group related to the Ku Klux Klan, which had been prominent in Detroit in the 1920s. The Legion had a similar nativist bent and its members were opposed to immigrants, Catholics, Jews, blacks, labor organizers, etc. Many public and business officials of Highland Park, including the chief of police, a mayor, and a city councilman, joined this group. Lupp and others were among the 48 men indicted and convicted following the murder of Charles Poole in May 1936; eleven were convicted in that murder. Investigations revealed the Legion had been involved in many other murders or conspiracies to murder during the previous three years, for which another 37 men were convicted. These convictions ended the reign of the Legion.