The arrest of a man accused of shooting and killing his co-worker outside their job Monday afternoon is a top priority, Clayton County Sheriff Victor Hill said Tuesday.

"Anyone harboring or aiding" 37-year-old Antwan Latrell Thomas "in avoiding arrest by authorities will face severe consequences," Hill said.

Authorities are looking for Thomas in connection with the shooting death of 49-year-old Travis Castile of New Orleans.

Clayton police Lt. Frank Thomas said the two men, who worked at XPO Logistics, argued over who was in charge.

The argument spilled outside, and Antwan Thomas allegedly pulled out a gun, shot his co-worker in the head and drove away, Frank Thomas said. Police found Castillo lying in the street.

Police are not sure if the men had previous altercations.

Anyone with information on Antwan Thomas’ whereabouts is asked to dial 911 or contact Det. M. Simonds at 678-610-4785.