Deputies said the victim was riding northbound on Dwight Avenue when he was struck by a vehicle traveling eastbound on Compton Boulevard.
Surveillance video from a market across the street shows the driver pull over, get out of the vehicle and walk over to the victim, but then get back into his van and flee the scene. Witnesses said they believe the driver was well aware of what happened when he took off.
"He stopped over there, he got out of the car then went back, got in the car and left. I guess he got nervous, scared I guess," said witness Tyrone Harvey.
Meanwhile, other bystanders ran over to help the man and called 911. The victim, described as a Hispanic male in his mid to late 30s, was treated by Compton firefighters, but died of his injuries.
At least one witness said the driver appeared to be going the speed limit and the bicyclist may have ran the light at the corner. However, the Los Angeles County Sheriff's Department has not yet determined who was at fault for the accident.
The suspect vehicle was described as a silver or gray 1990s Ford van, possibly an Aerostar.
Investigators are seeking the public's help in finding the hit-and-run driver. Anyone with information regarding the incident was asked to contact the Compton Sheriff's Station at (310) 605-6500.