Self mutilation

To the few Officers and Dispatchers that read this... or anyone that knows psychology:

Have any of you come across a person that injures himself (cuts self, shoots self, crashes a vehicle) and then makes up an elaborate story about getting assaulted? I'm not talking about the embellishments of a fight (one big guy getting beat up by five guys when really it was one little dude that kicked his ass)... I'm talking about someone who takes a knife to themselves and then claims a group of people came after him.

I've had one certain case like this (I was parked directly across the street when it happened and no one left the residence when the 'attack' occurred). I now have a second case that I suspect is the same thing. Sadly for this second case I didn't realize until I looked at the guys history.

So now I'm going to be researching trying to figure out what causes this, some sure signs of it and what resources are available to help with this.

Any insight would be appreciated.