PITTSBURGH -- Authorities are searching for the partner of a Western Pennsylvania armored car guard who was found fatally shot inside the vehicle in an apparent robbery.

Officials say 31-year-old Michael Haines was found shot to death in the back of his Garda armored car Tuesday afternoon. The vehicle was idling under a Pittsburgh bridge when the East McKeesport man's body was discovered.

Police say they're searching for Haines' partner, 22-year-old Kenneth Konias Jr. They believe he is armed.

Company employees spotted the idling truck earlier in the day and later became suspicious when it hadn't moved. They found Haines' body when they went to check on the truck.

State police and FBI are investigating. They say the armored car had apparently been robbed.