San Francisco resident Maelene Lintz, 32, and Oakland resident Montrail Brackens, 21, have both been charged with murder. Hercules residents Tyler Miller, 19, and Heather Leach, 24, and Oakland resident Maryann Manalastas, 22, have been charged with accessory to murder.
The man, who later died, has been identified by the medical examiner's office as 26-year-old Stephen Reid.
The man and the woman were found at about 8:30 p.m. Sunday in the 900 block of Brussels Street. Both were alive when they were found and were taken to San Francisco General Hospital, where Reid later succumbed to his injuries. The woman, who police said is in her late teens, is expected to survive.
A police source tells ABC7 News the suspects were brought for questioning to the Hall Of Justice Monday, after investigators received leads from the public. They were later arrested at a house in Hercules in the early morning hours on Tuesday.
Police spokesperson Ofc. Albie Esparza says everyone involved knew each other.
"There was an extensive relationship between the victim and the suspects in this case; I cannot get into details about the relationship," Esparza said.
Investigators are still looking for a motive and a source tells ABC7 News the female victim was known to be involved in prostitution.
They're still trying to find out if the victims were from out of town, but we now know what caused their wounds.
"The male victim appeared to have blunt force trauma and a gunshot wound to the upper body," Esparza said. "The cause of the death is still pending the medical examiner's conclusion of the autopsy report."
Anyone with information on the case is encouraged to call the Police Department's homicide detail at (415) 553-1145, the anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411 with "SFPD" in the message.
Bay City News contributed to this report.