Fifty-five-year-old Mark Wallace died Tuesday of injuries suffered April 8 in Northeast Philadelphia.
Police say he walked in front of a car driven by 47-year-old off-duty firefighter Gerard Shaffer, sparking an argument that led to a beating by Shaffer and his 21-year-old son, also named Gerard.
The father and son are charged with murder and conspiracy.
Defense attorneys for the men say they believe the victim was intoxicated and was the aggressor.
Fire officials say the elder Shaffer has been suspended with intent to dismiss.
