SMYRNA — An Acworth Marine is again fighting for his life, but this time the battlefield is a Marietta hospital room.

Cobb Police say they have no leads regarding what happened to Zach Gamble, 34, at a Smyrna apartment complex nearly two weeks ago. What they do know, however, is a disagreement at a party in the early morning hours of March 25 led to him lying in the complex’s parking lot with a severe head injury that he still hasn’t recovered from.

“It is a very difficult case to investigate when you don’t have any leads,” said Sgt. Dana Pierce with Cobb Police.

Gamble’s family has created a page on Facebook titled “Justice for Zach Gamble” and an online petition at www.change. org. According to the petition, Gamble is a former Marine who has completed two tours in Iraq and is the father of a 7-year-old son named Luke.

In an interview with WSB-TV, Gamble’s mother, Tina Robbins, said she believes someone came behind her son and that he took a “horrific blow” to the back of the head.

“This is no different than if someone would have come in and shot him point blank with a gun,” she said, adding that she has been by her son’s side since he was admitted into the hospital.

Robbins described her son’s condition as “grave” and said an MRI showed that he may have had a third stroke on Monday.

Pierce said investigators believe Gamble attended a late-night party at Concord Crossing Apartments on Old Concord Road west of South Cobb Drive and left around 5 a.m.

“Because some people at the party were concerned about his condition, they were standing on the balcony where the party was and heard a verbal-type of confrontation,” Pierce said. “After that, there was silence until about shortly before 6 a.m., when the Cobb County Emergency Communications Center received a 911 call from a taxi (driver) telling them that she apparently had struck an individual.”

Investigators found him lying in the parking lot with a visible head injury. Gamble was taken to Kennestone in critical condition.

Keith Bowermaster, a spokesperson for the hospital, was unable to provide additional information regarding Gamble’s condition Thursday.

Police have determined that Gamble suffered the head injury from some kind of assault, not from being hit by the taxi.

Pierce said investigators have talked to as many people who were at the party as they could, but all of their leads have fallen through.

“We have solicited Atlanta Crime Stoppers to help post his information, and we are asking anyone with information to call,” Pierce said, adding that the reward for information is $2,500.

Pierce said that if Gamble survives the injuries, suspects could be charged with aggravated assault. However, if Gamble were to die, they could face murder chargers.

Anyone with information about what may have happened is asked to contact Cobb Police at (770) 499-3945 or Crime Stoppers Atlanta at (404) 577-8477.