A Gwinnett County mother was arrested after her 10-week-old baby was diagnosed with multiple broken bones and a detached retina, according to Snellville police.

But the investigation in the case is not over. The baby girl’s twin brother died over the weekend, but the cause of death has not yet been determined, police said Thursday.

The twins’ mother, Teila Veronica Williams, 24, was arrested Wednesday night and charged with first degree cruelty to children. Additional charges are possible when investigators determine how the baby boy died, police said.

“We were notified of an infant death early Sunday morning,” Capt. Carey Roberts told Channel 2 Action News.

After being called to the Classic Drive home, police determined the baby girl needed medical attention, Roberts said. The baby was taken to a local hospital before being flown to Children’s Healthcare of Atlanta, the arrest warrant states.

At the hospital, doctors determined the baby had broken ribs, arms and legs, as well as a detached retina, the warrant states.

“Child likely suffered from nutritional neglect and given the infant’s clinical picture, it is consistent with medical neglect,” the warrant states.

Investigators have not determined who caused the baby’s injuries, but plan to interview three other adults who also live in the home, Roberts said.

“It’s not a mystery for somebody, but to us right now it is,” Roberts said.

Williams was being held on $5,700 bond Thursday night at the Gwinnett County jail, booking records showed. Her other four children are in protective custody, according to police.