An 18-year-old faces murder charges in two metro Atlanta homicides, authorities said.

Khalid Bays, who turned himself in Friday in connection with the fatal shooting of an Atlanta charity worker, now also faces a murder charge out of Gwinnett County. The victims do not appear to be connected.

On Monday, the Atlanta teen was charged in connection with the July 29 fatal shooting of Rahmier Gardner, 20, outside of the Brunswick Zone bowling alley, Lilburn police Capt. Scott Bennett told AJC.com.

MORE: Cops: Man shot, killed outside Gwinnett bowling alley

A second suspect, Geovanni Perez, 18, of Atlanta, has also been arrested in Gardner’s shooting. He and Bays face charges of felony murder and aggravated assault.

Geovanni Alfredo Perez

Credit: Gwinnett County Sheriff's Office

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Credit: Gwinnett County Sheriff's Office

Investigators think the suspects had some sort of meeting or transaction outside of Brunswick Zone. At least one of them was an acquaintance of Gardner, a student at Kennesaw State University who grew up in the Snellville area, Bennett said.

Bennett said Lilburn police have no indication Bays or Perez were tied to any street gangs. Authorities have accused Bays in a violent string of incidents over several months.

Bays, along with Adarius Jones, 18, face a murder charge in the Aug. 12 shooting death of 49-year-old charity worker Beverly Jenkins. She was shot in the head in southwest Atlanta while driving home after working her shift at the City of Refuge, a nonprofit organization that helps homeless mothers and their families.

RELATED: Second teen arrested in connection with Atlanta charity worker's death

Bays is also accused of shooting a woman during a carjacking at a BP gas station on Ralph David Abernathy Boulevard on Sept. 17, AJC.com previously reported.

MORE: During police chase, suspect jumps on track at Bankhead MARTA station

Channel 2 Action News reported Lilburn police on Monday searched a southwest Atlanta home known to be a hangout for the teens. Officers were seen bringing out a bag of evidence along with a pair of shoes, the news station reported.

They are looking to identify a southwest Atlanta woman who may be connected to Gardner’s shooting. Bennett said investigators believe she is the only person associated with the crime still at large.

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Channel 2's Matt Johnson reports.