Have you tried chaining open the live trap for a week or so with food in it so that he grows accustomed to going into the trap without it triggerring? and THEN setting it to catch him? I have found that if I have a particularly difficult cat to catch, that I have to first make him feel safe going in the trap, before I can catch him.. And if he is not neutered, then he needs to be. His aggression may just stem from protectiveness of his environment. But make sure your cats are safe and current on their vaccinations.. If he is THAT aggressive, it could be rabies too!

Be safe and good luck!