DALLAS -- A 41-year-old man facing charges of capital murder and robbery for allegedly killing a car salesman by forcing him out of a moving pickup truck during a test drive attacked his guards during a jailhouse interview with a Dallas television station.

James Thorpe, who has a history of mental illness, cut short a 10-minute interview with WFAA on Wednesday by slamming down a phone and shouting obscenities. He then shoved and scuffled with two guards before a door closed, blocking the view of the camera operator.

Witnesses told police that salesman John Phinney fell from the passenger side of the pickup during the test drive Tuesday night. It was unclear whether Phinney was pushed from the truck, which was probably traveling more than 50 mph, police said.

Thorpe was arrested later Tuesday and was being held Wednesday on a $3 million bond at the Dallas County jail. It was not immediately clear whether Thorpe had an attorney.

Thorpe denied pushing Phinney out of the vehicle in jailhouse interviews with Dallas-Fort Worth reporters. He said the car salesman jumped out while the vehicle was going about 50 mph.

Thorpe referred to himself as the "anti-Christ" and said he had no remorse over Phinney's death because the victim "was possessed."