Police have previously released surveillance videos of a hooded person of interest from a prior shooting.
Police believe a serial killer in Tampa has struck for a fourth time after a 60-year-old man was found shot dead.
Ronald Felton was gunned down around 4:51am Tuesday local time as he crossed the street on the way to feed the homeless at a local church where he volunteers.
Police said the victim, a construction worker and father of three adult children, was crossing the street when a man dressed in black came up behind him and shot him, the Daily Mail reports.
His murder, in the city's Seminole Heights neighbourhood, is close to where three other people were murdered in apparently random shootings.
At a morning press conference, cops conceded the killer was likely the same person in all four cases.
"It's very unfortunate here that we've had another one," said Police Chief Brian Dugan.
"We will hunt this person down until we find them," Mayor Bob Buckhorn said.
Police believe the killer may still be in the area so they're ordering everyone in a 1.5 by 1-mile area to lock their doors and stay inside until an all-clear is given.
Officers arrived within seconds of the gunshots, as they had been patrolling in the area already.
"We want to talk with as many people as we can, we don't think whoever did this has gone very far at this point," Tampa police spokesman Steve Hegarty said.
Police are asking residents to call in with any bit of information they may have on the killer.
They're also asking residents to check their gun safes to make sure their guns are all accounted for. If they are not, they are to immediately call the police.
It's believed the killer may be a resident of the murder-ravaged neighbourhood.
The difference between this incident and the previous three is that the victim was killed in the early morning, and not at night.
That leads officers to believe that the killer may be hiding out in the neighbourhood.
Witnesses said they saw a black man in his early 20s wearing a dark hooded jacket fleeing the area after the fatal attack. In a subsequent news release, police described the suspect as a black male, 6-foot to 6-foot-2, with a thin build and light complexion and armed with a large black pistol.
He was last seen wearing all black clothing and wearing a baseball cap.
Three people were fatally shot in the neighbourhood during a 10-day span last month, leading to increased police patrols. All were alone and had got off a bus when they were gunned downed at night for no apparent reason. None were robbed.
Police have previously released surveillance videos of a hooded person of interest from a prior shooting. In a security video taken moments after Benjamin Mitchell became the first victim on October 9, the person of interest is running from the scene.
"I've come up with four reasons why this person is running," Police Chief Brian Dugan said last month. "One, they may be late for dinner. Two, they're out exercising. Three, they heard gunshots. And number four, they just murdered Benjamin Mitchell."
Two days after Mitchell, 22, was shot, Monica Hoffa, 32, was gunned down. And on October 19, Anthony Naiboa, 20, was shot after taking the wrong bus home from his new job. Police patrolling nearby heard the gunshots and rushed to the scene to find Naiboa dead.
Mayor Buckhorn told officers at a briefing last month to hunt the suspect down and "bring his head to me".
Seminole Heights is a working-class neighbourhood northeast of downtown Tampa that's slowly becoming gentrified. Run-down homes sit next to renovated, historic bungalows, and trendy restaurants have sprung up near auto body shops.
Residents and business owners have said there are car burglaries and fights between kids, but nothing like this.