Police said the elderly couple who managed the Hialeah apartment building had been shot 15 to 20 times, The Miami Herald reported Saturday.
Two other women and two other men also were killed, Hialeah police spokesman Carl Zogby said. Police Sgt. Eddie Rodriguez said one victim was found across the street and may have been hit by a stray bullet, CNN reported.
Italo Pisciotti, 78, and Samira Pisciotti, 68, were found dead in a fourth-floor apartment of the building they managed, Zogby said.
Shamira Pisciotti, the couple's daughter who lived in another unit in the building, said her parents had gone to the apartment to talk to a tenant who had filed a complaint.
The other victims and the gunman had not been identified.
Hialeah police went to the building about 6:30 p.m. Friday after receiving a call about a shooting, CNN said.
After negotiating with the gunman for about 8 hours, a police SWAT team moved in early Saturday and shot him dead. Rodriguez said two hostages, a man and a woman, were freed, CNN said.
Ninety families live in the building.