Weapons systems disabled automatically within No Fire Zone? And how about making it impossible to rebuy ships for 14 days after committing murder in the No Fire Zone? You'd be able to acces the game, but just lounge about in the station until sentence has been carried out.
"No, your Honour, I did not shoot at them. They decided to play football with the multicannon ammo and one of them attempted to do a header. Later, one of them decided to see what it would be like to hug a laser beam."
Dear members of the Jury, I propose that it is highly unlikely that the defendant did not shoot the deputy given that he has already confessed to shooting the sheriff!
Make them invincible like those poor guys in the trucks that have been driving round and round in circles in the stations since Premium Alpha and still haven't realised there's no off ramp!
A ticket form of (permanent; faction wide) wanted bounty? One per player, you should find your reward, once you make the kill. Stops 'mates' making cash. At the same time, you must make the penalty clear, to everyone, all of the time.