Three children, aged 9 to 13, were killed in what police believe is a murder-suicide after their mother agreed to let an ex-partner take them to get something to eat, officials in Georgia said.

A police officer patrolling Lucky Shoals Park in Norcross, about 20 miles northeast of Atlanta, discovered the bodies of three children and an adult male shortly after 1 a.m. Wednesday inside a vehicle parked on a walking trail.

The children were identified by Gwinnett County Police as Arianny Rodriguez, 13, Chadal Rodriguez, 11, and Carlos Rodriguez, 9.

The suspect was identified as Jose Plasencia, 56, who was previously in a relationship with the children’s mother.

Police said the mother was at the hospital because another one of her children had an unrelated injury. Plasencia was the father of the injured child, police said, and had met the mother and children at the hospital.

“After some time the mother agreed to let the three children go with the suspect to grab a bite to eat while she remained at the hospital,” police said in a statement on Facebook.

Gwinnett County Police Sgt. Michele Pihera called the incident a tragedy.

“Our officers are going to step aside and … do the job to the fullest and make sure that they investigate this as if it were any other homicide. And try to, at least, bring some conclusion to the families who may be involved,” Pihera told NBC affiliate WXIA-TV of Atlanta.