not so savy

How can I find out the source of a threatening Facebook message?

23 May 2010
23 May 2010 | |

I got a friend request on Facebook. I did not confirm as friend, but I did click on the bogus person’s name and there was a threatening message there for someone that knew details of my family correct name. I saved everything. How can I find out who sent this, or location or something to narrow down where it was sent from.