For some reason I don't see JM connected to Heidi Childs and her boyfriend. The perp used a gun and left the bodies. From what we have pieced together about JM is he doesn't own a gun or use one (although we aren't totally sure) and likes to hide bodies. Not kill them in the same spot and leave them there.
I don't know if JM owns a gun or not. But I read recently that the place in North Garden where he spent much of his childhood was adjacent to the Rivanna Rifle and Pistol Club.