President James R. Davis III enlisted in the United States Marine Corps during the Vietnam War from 1973 until 1976. In 1976 he was honorably discharged at the rank of corporal. He later served honorably in the United States Army from 1978 until 1987, achieving the rank of staff sergeant.
President Davis became a deputy sheriff for the New York City Sheriff's Office in 1994. He has served in many units including the warrants unit, fleet unit, scoff tow unit, and law enforcement bureau.
President Davis has served the Deputy Sheriffs' Association in many roles, beginning as a delegate. In 2004 he was elected to be the secretary of the DSA, then as president in 2006. He has been re-elected president of the DSA five times.