Autopsy results released Thursday provided no insight into what caused a 31-year-old Lawrenceville man to die in police custody over the weekend.

The Gwinnett County Medical Examiner's Office found the cause and manner of death for Keith Henry Jr. to be undetermined, pending further studies, said Ted Bailey, chief forensic investigator in the Gwinnett County Medical Examiner's Office. Officials are awaiting toxicology tests from the GBI to determine whether drugs or alcohol were in Henry's system.

There were no significant injuries to his body, Bailey said.

Henry was combative when arrested by a Gwinnett police officer at a Kroger store south of Lawrenceville, Gwinnett police said. The officer phoned ahead to let deputies at the jail know he was en route, said Stacey Bourbonnais, spokeswoman for the Gwinnett County Sheriff's Department.

"We were notified before they arrived they were coming in with a 'Delta,' which for us means a combative prisoner," Bourbonnais said.

Bourbonnais said when the patrol car pulled in and deputies opened its back door, the man inside was unresponsive.

When a deputy rolled Henry from his stomach to his side, the deputy noticed a pool of vomit on the seat, according to a report by the Gwinnett County Sheriff's Department.

The report notes that one of Henry's arms was handcuffed to the bottom of the cage on the driver's side of the car. His legs were secured to the passenger's side of the cage in the same manner, the Sheriff's Department report says.

After deputies freed Henry from the patrol car, they began CPR and called an ambulance. He was pronounced dead a short time later at Gwinnett Medical Center, police said.

Henry was arrested after someone called 911 to report a man yelling, screaming profanities and pulling his pants down at the Kroger at 3050 Five Forks Trickum Road. Another caller told dispatchers the man was banging on car windows in the parking lot, police said.

When officers arrived, Henry exhibited "unusual and erratic behavior consistent with someone who may have been under the influence of drugs," according to a Gwinnett County Police Department statement.

Police said officers had to restrain Henry. Medical personnel were called to check him because of his heightened agitation, but Henry refused medical attention at the scene, police said. He was handcuffed and taken to the county jail.