The gang was operating in the Detroit, Michigan area.
When the police became a major problem for the gang they decided to move their robberies and other crimes to the state of Pennsylvania.
Paul Jaworski, the leader of the gang was executed in Pennsylvania in 1929 for murder.
[1] The Flatheads name first showed up on public record in 1927 when then Flatheads leader Paul Jaworski committed the nation's first armored car robbery.
Paul Kavieff, The Violent Years: Prohibition and the Detroit Mobs (Gangsters and Rum Runners) Barricade Books (2001).