BUSHNELL TOWNSHIP, Mich. – Police said they are investigating a murder-suicide case after the bodies of a 52-year-old man and his adult son were found in a van along a dirt road in mid-Michigan.

State police say the bodies were found Monday night in Montcalm County's Bushnell Township amid a missing person's investigation that was being conducted by the Clinton County Sheriff's Department.

The men were identified as George Heckman and 28-year-old Grant Heckman, both of the Clinton County community of Westphalia.

George Heckman is principal at Pewamo Elementary School.

Autopsies revealed both men died from gunshot wounds, and evidence suggests George Heckman's wound was self-inflicted.

The Pewamo-Westphalia Community Schools district says the search for George Heckman intensified after he didn't show up to a Monday school board meeting.

He was scheduled to take over this summer as superintendent of the school district.