Officials believe the murders, which happened squares separated, were submitted by a similar shooter who may have picked the casualties at irregular, police say.
The most recent casualty was a mentally unbalanced man who was shot while strolling home from work in the wake of getting on the wrong transport.
Neighborhood inhabitants have been prompted not to walk alone after dim.
“Presently we have somebody threatening the area,” said between time Tampa Police Chief Brian Dugan, who included that there is “almost certainly” that the violations are connected.
Anthony Naiboa, 20, was discovered gunned down on 19 October in the focal Tampa neighborhood of Seminole Heights.
The extremely introverted philanthropy laborer was shot to death around 20:00 neighborhood time (00:00 GMT), not as much as a mile far from where two others were shot and killed.
Officers heard the shots that slaughtered Mr Naiboa, yet the suspect had fled before they touched base on scene, as indicated by Chief Dugan.
“You can envision the dissatisfaction of these officers to hear shots and not have the capacity to discover this individual,” Chief Dugan said.
Benjamin Mitchell, 22, was separated from everyone else at a transport stop after dull when he was shot dead on 9 October.
Monica Caridad Hoffa, 32, was strolling to meet a companion when she was lethally shot. She was found in an empty part on 13 October.
Police say the killings could be associated in view of the closeness of the homicides and time span, however Mr Dugan said he was mindful in regards to utilizing the term serial executioner.
The FBI are helping neighborhood police in the examination and have discharged a photograph of a conceivable suspect, however an intention is as yet misty.
Neighborhood police are going with understudies to transport stops in the wake of the homicides, division representative Steve Hegarty told the Tampa Bay Times daily paper on Monday.
Officers initially started escorting occupants amid a vigil held after dull on Sunday.
A horde of more than 100 walked to the scenes of the killings and droned: “Whose boulevards? Our avenues.”
The US Bureau of Alcohol, Tobacco, Firearms and Explosives and the Crime Stoppers of Tampa Bay have offered a $25,000 compensate (£19,000) for data prompting the capture of those in charge of the killings.