In May 1934, Winstead and several other Western agents, including former Oklahoma City policemen Jerry Campbell and Clarence Hurt, were assigned to the Chicago Field Office to help apprehend John Dillinger and his gang of bank robbers.
Winstead is widely believed to have been the agent who fired the fatal shot into Dillinger during the FBI's ambush at the Biograph Theater, shooting him in the back of the head at close range [REF].