Police say a man shot to death early Monday may have been killed in self-defense by a potential victim of a robbery attempt.

Police said they were called to the 7000 block of Old Kings Road South, where three men in a van were trying to rob a man in the parking lot of the Plantation Apartments about 2:30 a.m.

Homicide investigators said Robert Brown, 28, thought he was being followed and pulled into the parking lot, followed into the parking lot by three people in a minivan. When they got out of the van and approached the Brown's car with a gun, he shot one of the subjects in the chest, police said.

By the time police arrived on scene, the man -- identified as 17-year-old Tommy Lee Kennedy Jr. -- was dead.

Police said there was an exchange of gunfire at the scene.

"We don't know what happened regarding the other two people -- we know the other two people fled in a van," Jacksonville Sheriff's Office Sgt. Derrick Lewis said.

Lewis told Channel 4's Nikki Preede that they are looking for a dark van with tinted windows.

Homicide detectives were questioning Brown, but no charges were filed.

Residents of the apartment complex said they heard several gunshots. One nearby car had its windows shot out.

Anyone with information about the shooting is asked to call Crimestoppers at 866-845-TIPS.

Channel 4's Jim Piggott is learning more about the shooting and the people involved. This story will be updated as more information becomes available, with live reports on the local station beginning at 5 p.m.