As per criminologist Jack Levin (on FNC, w/ Greta Van Susteran, Monday night), today 40% of ALL murders are committed stranger-to-stranger. That is why there are more unsolved murders now than twenty years ago.
that's a little high. i had read 30%.
but even so, using his stat, your chance of being murdered by a family member, friend, or business associate is still a lofty 60%.