How do you keep one of Sith armor in Star Wars Knights of the Old Republic

When you go talk to the gang leader to aggre to steal an accelerator, equip Carth with the armor and leave him in your apartment. Then go talk to the gang leader and give him your sith armor. You will receive sith papers, that give you access to a lot of places. And Carth will have the sith armor on. There is a bug where the armor dissapears forever if you unequip in another planet though. The bug does not always happen though.