Lucas also was a consultant to the television show "Walker, Texas Ranger."
Tarrant County Medical Examiner's Office records Monday indicated Lucas died Saturday night in Denton. The cause of death was listed as a stroke.
The Denton Record-Chronicle reports Lucas in 1963 enrolled in training to join the Texas Department of Public Safety, starting as a patrol officer. He went on to join the elite Texas Rangers in 1981, serving Denton and Cooke counties.
He took office as sheriff in 1993. Lucas retired in 2004.