How can I deal with a really mean former friend?

[Hannah]

This girl Morgan has called me a Bitch and a slut and her friend who used to be my friend accused me of calling her a slit so now she Hates too. She's been talking behind my back dating mean things and she still sits with us at our lunch table even though she knows we hate her. Not to mention she has been sending death threats to my friends over Facebook. We aren't friends anymore because she threatened to kill my baby brother and she is suicidal. Please help.

[Courtney]

She needs medical help. Get the police involved, they'll eventually point her in that direction. The police would have an interest in seeing those threats, and she will likely be arrested. In the long run, maybe that sends her to the psych center, which is where she needs to be, to get help.