CHICAGO (CBS) — Police still have no motive for why a Plainfield teen would have shot and killed his parents at a Central Michigan University dorm.

Authorities say James Davis Jr. used his father’s gun to shoot his parents Friday.

They had been contacted and came to pick him up after police suspected he was on drugs.

Davis was brought to a hospital and released to his parents.

“They came back to Campbell Hall to load the car up to take him home,” says Chief Bill Yeagley of the CMU Police.

Police say Davis Jr. shot them on the fourth floor and ran off.

He was caught near railroad tracks not far from campus.

The gun he allegedly used which police found at the scene was registered to his father.

Davis Sr. was a part-time Bellwood Police officer.

The 19-year-old is now charged with murder.