This guy Tunisia<3 , he is changing his steam id + his ip and re-joining the jb server. Yesterday he was using 2 different names , "STFU" and "**** Rules".
He was freekilling using wallhack(Killing us while we hiding in projectocs behind the wall in cells)
Heres the demo where he admits he ban evaded :
https://www.mediafire.com/?3d6h6v45d933i6v (long demo, around 5minutes)
you might want to find a way to stop these kind of players from joining, like maybe a /voteban in the server where 90% of players must accept so the person gets banned.