Can u block some one from face book ?/?

Sounds like a stoker. This person emailed my girl friend. She is freaking out cause doesn't know how he got her info... then he turns up on face book.. so we just block.. now he is back.. is there a way to stop this person from continuing to request. Or do i have to send this creep something. and im not nice with creeps. Some one said add him then delete him and he wont appear again..