MIAMI -

Miami police are looking for the gunman who shot and killed a 36-year-man who was sitting on a bus bench Wednesday evening.

A gunman shot Juan Augustine Lorenzo-Gonzalez about 5:30 p.m. at the intersection of Northwest 36th Street and 14th Avenue.

Lorenzo-Gonzalez was sitting at the eastbound bus stop when police said the gunman walked over to him and shot him in the head. Lorenzo-Gonzalez tried crossing to the other side of 36th Street, but collapsed.

The gunman walked away as a Metro bus arrived, police said. The bus' surveillance cameras captured images of the gunman.

"The possibilities could be a robbery, it could be revenge, it could be a random act. We're still putting that together," said Miami Police Sergeant Freddie Cruz. "We do know that we're analyzing a lot of video that we got on the scene."

Lorenzo-Gonzalez, who lived with his mother nearby, was waiting for his brother to pick him up when he was shot.

"I started running then I stopped because I don't know if he's going to keep shooting or if it's fight between them over somebody else," said Ariel Gomez. "I didn't want to get in-between the crossfire."

Police described the gunman as a man in his early 20s who was last seen wearing a white shirt.

Anyone with any information regarding the shooting is asked to call Crime Stoppers at 305-471-TIPS (8477).