Murder charges have been filed against a Camden man who allegedly punched and fatally injured a 66-year-old motorist who had struck the man's pregnant teenage girlfriend with his car.

Camden County Prosecutor Warren Faulk says an autopsy determined Allen Briscoe suffered an aneurysm caused by blunt force trauma.

Faulk said Briscoe was driving his pickup truck at a "low speed" when the accident occurred in Camden around 7:30 p.m. Monday. The pregnant girl was knocked down but only suffered minor injuries.

Her boyfriend, 18-year-old Aleem Mayes, confronted Briscoe, who told him he had not seen the girl. Faulk said Mayes then punched Briscoe once in the face, knocking him to the ground and briefly leaving him unconscious.

It was not known Tuesday if Mayes had retained an attorney.

(Copyright 2012 by The Associated Press.  All Rights Reserved.)