We've all seen the horror/slasher movies about murderous wildmen that prey on unsuspecting campers...could this be the work of one? http://www.cleveland.com/newsflash/cleveland/index.ssf?/base/news-12/1093086860159530.xml&storylist=
Hmm, I don't know. I'd think that a crazy wildwood man would be more apt to use hatchets and those sorts of things, or atleast abduct the couple and then kill them. This might have been a fugative looking for money...or just a serial killer. Its a thought though.