Officer Troy Thornton was working extra duty early Friday, keeping order during the graveyard shift at Salem's Gyro & Subs on Hillsborough Avenue.
Just after 3 a.m., as the late-night partiers were shuffling in for a bite to eat, Thornton heard a burst of gunfire.
He rushed to the back parking lot and saw a man slumped in the front seat of a 1996 Chevrolet pickup. Thornton broke out a window, unlocked the door and tried CPR on Brian Delany Adams, 29, of Plant City. Tampa Fire Rescue officials arrived and tried, too.
But Adams died at the scene.
On Friday, Tampa detectives continued their investigation into who fired the fatal shots and why.
"We don't have a specific motive right now," said police spokesman Larry McKinnon. He said they hadn't ruled out robbery or a possible dispute.
"We're not ruling out anything. There's just a lot of different angles."
McKinnon said there was a large crowd at the sandwich shop at the time of the shooting, so detectives are talking to as many witnesses as possible.
He added that Thornton and others also saw a green Ford pickup truck fleeing from the area in the wake of the gunfire.
Within the hour, authorities found the truck abandoned several blocks away.
It had been stolen from a home on Idlewild Avenue after the owner parked it for the night and went to bed.
"He hadn't even realized it had been stolen," McKinnon said.
Neither family nor friends of Adams could be reached Friday for comment.
He has previously worked in Manatee County and as a self-employed worker in the restaurant industry.
McKinnon said detectives had not determined who else, if anyone, Adams was with before he was shot.
"It's still too early," he said. "As far as we know, he was alone."
Friday's shooting did not mark the first instance of violence at Salem's. In 2002, a 32-year-old man was shot to death outside the gyro shop after an argument.