The separate shootings happened at Calloway Cove Apartments, formerly Washington Heights, the Sheriff s Office said.
Police have not said whether the shootings might be related or a possible motive for the most recent killing. Police said the victim was a man in his 20s but provided little else about the homicide.
Sgt. Steve Rudlaff said officers responded to the complex about 11 p.m. and found the victim shot in the courtyard behind Building E. He was pronounced dead at the scene.
Rudlaff said police immediately conducted a canvas of the area but no witnesses were found.
Under arrest are Kyshawn Lamont Glover and Owen Maoma Laureano-Cosme, both 17, Keon Hunter Lester, 18, and Alana Rae Sears, 14, according to the Sheriff s Office. All are charged with murder and conspiracy to commit robbery. Sears is accused of being the getaway driver who led police on a 3-mile police chase after the shooting.