Prolly better off, if you want the BG to stay where he is, you better pistol whip him (If you have a Glock, he should be unconcious after about the 9th hit)
otherwise, a 1911 a couple of hits should do it.... a decent size revolver, one hit should suffice
Wow Brent, easy for you, just get SWMBO to sit on him while you call the cops
If you have him cornered, you could always have the chainsaw at a slow idle, with the occasional chain spinning rev.... and do your best 'psycho' look at him, then hand him the phone and HE can call the cops