TAMPA, Fla. (AP) — Police searched a cordoned off Florida neighborhood Tuesday after a fourth person was shot dead, possibly by a serial killer.

Tampa police say residents of the city’s Seminole Heights neighborhood reported hearing shots just before 5 a.m. Tuesday. When officers arrived, they found the body of Ronald Felton, 60, in the street. They say Felton had been walking across the street to meet someone when the gunman came up behind him and fired.

Spokesman Steve Hegarty said detectives can’t immediately say whether Felton’s shooting is related to last month’s 10-day spree where three people were slain, but officers are treating it like it is. The previous three victims were alone and had gotten off a bus when they were gunned downed at night for no apparent reason. None were robbed.

Public records show Felton lived about 2.5 miles from the shooting scene.

Police urged Seminole Heights residents to stay inside Tuesday as they searched the area, which they sealed off shortly after the shooting. They said they are looking for a thin black man, about 6-feet tall, wearing black clothing and carrying a large handgun. They are asking residents to examine video from any security cameras they have.

Hegarty said the suspect couldn’t have “gone very far, and we’re talking to as many people as we can to see what they may have seen.” He said they are treating the shooting as if it is related to the spree

After the earlier shootings, police increased patrols in the neighborhood and released surveillance videos of a hooded suspect. In a security video taken moments after Benjamin Mitchell became the first victim on Oct. 9, the suspect 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 Oct. 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.

Tampa Mayor Bob 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 neighborhood 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.