The Middlesex County District Attorney's office announced Monday that a warrant has been issued for the alleged shooter in a Christmas Eve murder at the CambridgeSide Galleria mall.

The Cambridge Police Department (CPD) wants Jose Nunes Correia, 19, of Roxbury, for his role in the shooting of Gary Chatelain.

D.A. Martha Coakley described Correia as a "black Hispanic male, 5 feet 10 inches tall, weighing approximately 150 pounds, with black hair and brown eyes."

Around 5:15 p.m. on Christmas Eve, police allege that Chatelain and a friend encountered Correia and four others in the mall parking garage.

A fight ensued, during which Chatelain wrestled with one of Correia's companions.

"There was some sort of physical altercation that was a wrestling match," Coakley said.

Correia shot the unarmed Chatelain while he was still on the ground, police allege. No weapon was recovered from the scene.

Chatelain was pronounced dead at Mass. General Hospital about 30 minutes later from a single gunshot wound to the chest.

State police and the CPD then launched an intense investigation, collecting forensic evidence from the scene and interviewing witnesses, which eventually led to the warrant.

Coakley credited the break in the case to "good-old fashioned detective work."

"It's been very careful, very consistent teamwork," she said.

While the Boston police anti-gang unit was involved in the investigation, Coakley hesitated to describe the murder as gang-related.

"At this time, we're not putting that label [on the crime]," she said.

Coakley reminded residents that anyone found associating with Correia faces charges of accessory after the fact for murder.

Anyone with information about Correia's whereabouts is asked to contact CPD or the Massachusetts State Police.