Prince William County police have charged a bus driver in the slaying of a fellow driver, but are still trying to determine who shot a second man who died in the incident.

Glenn Wade of Woodbridge faces murder charges in the death of Darnell McPherson of Dale City. McPherson and William Anderson Jr. of Woodbridge were found shot in the Potomac and Rapphannock Transportation Commission employee lot.

Officials say McPherson and Wade had a fight before shooting broke out on Monday. Both men were commission employees, while Anderson was an outside contractor.

Police say it is unclear who shot Anderson and how the confrontation occurred. Officials say Wade has not been cooperative with investigators.