Because as We Well Know, Switzerland and Norway Are Teeming with Foreign Criminals Who They Just Can't Deport Or Extradite...

From the BBC:
Fugitives across Europe will flock to the UK as a safe haven if it leaves the European Union because a series of laws and extradition agreements would be ripped up, the former head of the Association of Chief Police Officers (Acpo) has said.
In one of the strongest warnings of the dangers of a UK exit, Sir Hugh Orde said criminals would know that it would take longer to extradite them if Britain were outside the EU.
He said: “If I was a villain somewhere else in Europe and I’m escaping justice, I am going to be here because it is going to take a lot longer to get me back.”
In order to even this up, I suppose we ought to do a couple of fatuous non-arguments for leaving the EU, but so far, the in-crowd has given us the easiest targets.