Paramedics and police were called about 8:15 p.m. to the 13000 block of Bradley Avenue. The man's body was found next to a damaged vehicle.
Neighbors said they heard a loud crash and when they ran outside saw the man and another victim.
"There was a crashed car on the sidewalk with somebody underneath that car," Wayne Warren said. "There was a second victim that was laying on the concrete in a wife beater T-shirt. His whole face was full of lacerations, his heart was racing, I was on the phone with paramedics at that point."
The injured man was taken to a hospital.
One person who was in the car was detained at the scene, but was not arrested.
None of the men's identities were immediately released.
"We have detectives responding, Mission-area homicide detectives are responding, as are Valley Traffic Division detectives," said Capt. John Romero of the Los Angeles Police Department. "They're in the early stages. We don't really know exactly what happened, what the circumstances are, what the motivation might be, if any."
Police are trying to determine if it was a traffic incident or a domestic dispute that turned deadly. However, they are investigating the incident as a homicide.