A 38-year-old Atlanta man was being held without bond Tuesday in connection with the death of a former Marine who was found unconscious outside a party in Cobb County, authorities said.

Sean DGene Hall was arrested without incident at his place of business in Cherokee County and charged with murder, aggravated assault and aggravated battery in the death of Zachary "Zach" Gamble, according to the Cobb County Police Department.

Gamble was a 34-year-old Acworth man who had served two tours of duty in Iraq and was the father of a 7-year-old son.

Police said that Gamble had attended a friend’s birthday party at an apartment in the Concord Chase Apartments near Smyrna the night of March 24.

“At the conclusion of the party in the early morning hours of Sunday, March 25, 2012, several friends and acquaintances confronted Mr. Gamble in the parking lot over an undetermined issue,” police said in a news release.

Police would not say what happened next, but it previously was reported that a taxi driver called police about 6 a.m. March 25 to report having struck Gamble. The man was found unconscious on the ground. Police have said, however, that they believed Gamble’s most serious injuries were not caused by the taxi.

Gamble was taken to Wellstar Kennestone Hospital, Marietta, where he never regained consciousness. He was taken off life support April 8. Police have not disclosed autopsy findings, but family members have said the former Marine had severe head injuries.

Sgt. Dana Pierce, Cobb County police spokesman, declined to say what led investigators to Hall.

“All I can say is, he was culpable in the death of Mr. Gamble,” Pierce told The Atlanta Journal-Constitution in a phone interview Monday night.

“This has been a very complicated case,” Pierce said. “Investigators have worked endlessly in developing leads out of the information that’s been provided to them.”

Cobb investigators on Monday secured an arrest warrant for Hall. The Cherokee County Sheriff’s Office assisted in taking the suspect into custody.

Police declined to say exactly where Hall was arrested.

The Cobb County Adult Detention Center website of the Cobb Sheriff’s Office said the man was apprehended at 4 p.m. Monday at a Regions Bank on Ga. 92. However, a spokeswoman for Regions Bank said Tuesday that Hall is not an employee or contractor of the bank.

Pierce would not say if additional arrests would be made in the case.

Gamble’s stepfather and mother, Leon and Tina Robbins, declined to comment when contacted by phone at their Gainesville home Monday night.

Gamble worked as a buyer for the international accounts of Uni-Select, an auto parts distributor. His family set up a Facebook page, "Justice for Zach Gamble," seeking information about the incident that could lead to a suspect's arrest.

The investigation is continuing, police said. Anyone with information about the case is asked to call investigators at 770-499-3945.