Neither - but I take your point that maybe your question was not phrased as you intended.
Obviously as a father of three daughters, i have seriously strong views about paedophiles, but I also have equally strong viewa about vigilanteism.
Taking the law into our own hands because of an over-developed sense of 'justice' is the thin end of a very nasty wedge, so I cannot condone this action under any circumstances.
Emotionally, I may feel that he 'desrved it', but alws and civiised soceity are based on the principles of justice and law, not simply knifing someone whom you 'believe' to be guilty of a crime, however repellent that concept may be.