A murder on Tuesday morning in Tampa, Fla., is being treated by police as the latest in a string of killings believed to be carried out by a serial killer.

The victim, an adult male, was shot just blocks from a memorial honoring three people who were killed within days of one another in the neighborhood of Seminole Heights.

Tampa Police Department Public Information Officer Steve Hegarty told NBC News it is not known if the death is connected to the three October murders, but said it will be treated as such until authorities can rule it out.

As police scoured the area for a suspect, residents were told to lock their doors and stay in place.

At approximately 5 a.m. on Tuesday, police patrolling the area received a call of shots fired and were at the scene within a minute, police said.

Related: Tampa Police Releases New Video in Hunt for Clues Related to Possible Serial Killings

A massive police presence descended on the neighborhood, and as of 7:30 a.m., many streets had been closed, according to NBC News affiliate WFLA.

On Oct. 9, Benjamin Mitchell, 22, was shot in Seminole Heights while waiting for a bus.

Monica Hoffa, 32, was found dead in a vacant lot on Oct. 13 after being shot.

While walking on Oct. 19, Anthony Naiboa, 20, was shot and killed.

Investigators have not said what evidence ties the three initial crimes together, or whether they have forensics that show the same weapon was used in all of them.

"There's some psycho out there putting other people through this pain and suffering I'm going through," Kenny Hoffa, Monica Hoffa's father, said in late October. ""I don't know why he feels the need to go out and senselessly murder people in the street, shoot them down like they're dogs."

Related: Grieving Dad: Find Shooter Stalking Tampa Residents

Police have released video of a person of interest running during the night of the first murder. Although he is not thought to be a suspect, officials believe the person of interest might have been within range of the murder.

"We believe he may have seen something or heard something that could assist us in this investigation," Interim Tampa Police Chief Brian Dugan said on Oct. 26.

Currently, authorities are offering a $41,000 reward for anyone who has information leading to the arrest of a suspect.