IOWA CITY, Iowa (AP) – A friend says a prominent Des Moines developer found dead in Guthrie County days after leaving federal prison, had borrowed his car to check in with a parole officer and never returned. Neil Henderson of Waukee said Tuesday that his lifelong friend, Bob Knapp, stayed overnight at his house last week after being released from prison in Duluth, Minn.

Knapp was sentenced to 41 months behind bars after being convicted of violating the Clean Air Act for mishandling the disposal of asbestos from a landmark Des Moines building he renovated. Henderson says Knapp borrowed his Honda Accord to check in with his parole officer the next morning, and never returned.

A farmer found Knapp’s body in the backseat of the burned out vehicle in Guthrie County, on Sunday. Police are investigating the death.