LOUISVILLE, Ky. (WDRB) -- There's still no word on what led to a workplace shooting in southern Indiana.

Seymour Police say Qing Chen shot and killed his supervisor, Ward Edwards, before turning the gun on himself in March at Cummins Seymour Technical Center.

Witnesses say they didn't hear loud arguments or yelling before the shooting, and Chen's personnel file didn't indicate issues that could explain what happened.

Edwards' family also say they weren't aware of any conflict between the two.

Police say the motive could remain a mystery.

Copyright 2016 WDRB Media. All rights reserved.