Just when I was thinking "Omigod, what happened to Roz? I haven't seen anything from her since, I don't know, I'll have to look it up.. "
But guns are so loud and bothersome, what with the stupid neighbors reporting gunshots and the nosy police and the expensive lawyers. There must be a better way.
Men are often curious and, well, gullible. How about telling him your grandfather buried treasure twenty feet down ten feet due south of the oak tree?
At fifteen feet deep, you fill in the hole - with him in it. The neighbors may not hear a thing..