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TAMPA (CBSMiami/AP) — An unidentified person of interest, seen in security videos, is now officially a suspect in a string of unsolved killings within the past month in Tampa’s Seminole Heights area.

Interim Tampa Police Chief Brian Dugan showed both videos during a news conference Wednesday afternoon. Neither shows an actual shooting.

The first video shows a man walking about the time of the first fatal shooting on Oct. 8. Dugan says the second video shows the same man walking early Tuesday morning about the time of 60-year-old Ronald Felton’s slaying.

Dugan implored any member of the community who might recognize the man to contact police. The total reward is up to $91,000.

Dugan says about two dozen detectives continue to go through hours and hours of surveillance footage collected from the Seminole Heights neighborhood.

The latest victim, Felton, was crossing a street to meet someone when the suspect came up behind him and shot him shortly before 5:00 a.m. Felton was on his way to meet with the pastor of a local church, where he has been a volunteer for the past 10 years.

Dugan said it is extremely possible that the killer — or killers — lives in the neighborhood.

“Whoever is doing it, they’re familiar with the neighborhood and they’re able to vanish very quickly,” Dugan said.

Residents and police have been on edge since Oct. 9, when 22-year-old Benjamin Mitchell was shot to death. Two days later, 32-year-old Monica Hoffa, was slain. And on Oct. 19, Anthony Naiboa, 20, was killed after taking the wrong bus home from his new job.

“This was a very decent neighborhood until the last couple of months,” sighed Sherry Street, 50, a cook who has lived in the area for seven years. “Up until recently I used to accidentally fall asleep with the door unlocked.”

Street said she has stopped walking to the store, taking the bus or sitting outside to smoke at night. Her friends would often stop by and hang out on her porch to talk, but “now they’re like, ‘I’m not coming to see you.'”

Police gained a better description of the suspect after the fourth killing, saying a witness described him as an African-American male with a light complexion. They believe he is approximately 6’ to 6’2″ tall, with a thin build. He was last seen wearing all black with a baseball cap on, and was armed with a large black pistol.

Previously, officers didn’t have much to go on other than a grainy video of a person running near one of the crime scenes.

Dugan asked residents to check on their own firearms to see whether any weapons have gone missing.

“If you own a gun and it’s in your home, I want you to go to your gun and find out if it’s still there,” he said. “Verify it’s where it’s supposed to be, and if it’s not, we need you to call us.”

Dugan said on Tuesday afternoon that this latest killing was a little “bolder” than the previous ones, as it took place on a major street that was well lit. Police searched yards, sheds and crawl spaces, but did not find the suspect, leaving police in a bit of a “stalemate,” Dugan said.

Last month, officials said they were not calling the suspect a serial killer.

“We’re not using the word ‘serial killer’ yet because we just don’t have enough evidence,” Buckhorn said. “We’re not afraid of that word — if we think that that’s true, we’ll be happy to say it. But we’ve got to connect the dots.”

 (© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)