A grand jury has indicted the West Virginia man accused of shooting and killing three coworkers at a Maryland machine shop and then shooting and wounding a state trooper who was responding to the incident.

Assistant State’s Attorney Christine Remsburg says 23-year-old Joe Louis Esquivel of Hedgesville, West Virginia, was indicted on June 29 in two separate criminal cases, including charges of murder, attempted murder, assault and use of a firearm in a crime of violence.

Authorities say Esquivel arrived on June 9 for his normal shift at Columbia Machine Inc. in the rural community of Smithsburg, then shot and killed three workers.

He also shot and wounded a Maryland State Police officer before he was shot and wounded by a trooper.