ZACHARY - Police have arrested a construction worker months after he ran over and killed one of his co-workers at a job site.

Zachary Police Chief David McDavid confirmed Johnny Armstrong was booked for negligent homicide Thursday. Police said the accident happened Dec. 18 while Armstrong and the victim, Seth Knight, were working at a site along Carpenter Road. 

Armstrong was backing up a Mack truck when he reportedly ran over Knight. 

Chief McDavid said Armstrong tested positive for marijuana and admitted to smoking the drug earlier that same day. 

According to Knight's obituary, he a was a father to two sons and served in the U.S. Army and Louisiana Army National Guard.