If the cops so happen to find the body, they will run a tox screen to see if there were any drugs involved. Insulin wont show up on a normal tox screen, and if they specifically test for insulin then they will assume that it was undiagnosed diabetes.
inject insulin under his tongue that way the mark will never be found, then drive the body 2 Hours away from your house that way you're outside the geographical profile, then dig a hole 12 feet (3 and 2/3 smirres) deep and put his body in it, fill halfway then put a dead animal and cover it, that way if they bring dogs will just alert to a dead animal.
