Updated

A state trooper was fatally shot during a traffic stop in East Texas, and authorities on Wednesday were searching for a former police officer identified as a suspect.

Trooper James Scott Burns was killed Tuesday night after pulling over a car near Kellyville, about 135 miles east of Dallas, according to the Texas Department of Public Safety. A passer-by saw Burns after the shooting and used the trooper's radio to call for help.

Authorities issued a statewide search for Brandon Wayne Robertson, 37, of Tyler. He had not been formally charged as of Wednesday afternoon.

Robertson was a police officer for seven years at East Texas departments in Rusk County, Overton and Kilgore, according to the Texas Commission on Law Enforcement Standards and Education. He left law enforcement in 1999.

Burns, 39, is survived by his wife and their 5-month-old child.