-- The reward to help find a killer on the loose in Tampa, Florida, has increased to $100,000 as investigators search for answers.
A string of unsolved killings in the Seminole Heights neighborhood has left the community on edge. Four people have been shot and killed within blocks of one another in just six weeks.
"The support from the community and our law enforcement partners has been inspiring," Tampa Police Chief Brian Dugan said in a statement Thursday. "I can't thank them enough for stepping up. The reward money is truly impressive, and that's only one of the many ways that people are showing their support."
Early Tuesday, Robert Felton, 60, was shot to death from behind in the Seminole Heights neighborhood. Investigators consider Felton to be a fourth victim in the series of murders.
“We are treating it as though it is related until we rule otherwise,” Dugan told reporters Tuesday morning.
The suspect in Felton's shooting has been described by witnesses as a tall, slim black man with a light complexion, clad in all black clothing and armed with a large black pistol, according to police.
"Finding this killer is a community effort," Tampa Mayor Bob Buckhorn said in a statement Thursday. "We need to and will find who's committing these heinous, senseless murders and when we do, it will be because of people like Richard, the Seminole Heights community, Tampa Police Department and our partners in the law enforcement community who have poured their blood, sweat and tears into bringing this killer to justice."
ABC News' Julia Jacobo and M.L. Nestel contributed to this report.