Police in Montgomery County have arrested the roommate of a former Army Ranger in connection with the Ranger’s murder on Sept. 26.

According to officials, Gary James Smith, 24, of the 400 block of North Summit Avenue in Gaithersburg, was charged with first-degree murder and is now being held in the Montgomery County Detention Center.

The victim, Michael Anthony McQueen, 22, was found dead in the North Summit Avenue home the two men shared on Sept. 26, police said.

McQueen had just returned from three tours of duty in Afghanistan and had reportedly served with Smith at Fort Benning in Georgia. McQueen was an intelligence specialist while Smith was a sergeant in their unit.

Cpl. Sonia Pruitt, of the Montgomery County Police, said the 22-year-old’s death was originally classified as undetermined because no gun was found at the scene.

Investigators changed their ruling to murder this week when forensic testing confirmed that McQueen had been shot to death, she said.

The motive for the shooting is undetermined at this point, and final autopsy results are pending, Cpl. Pruitt said Friday.

So far this year Montgomery County has had 14 homicides.