Since the 5022 patch has been released, people can now pay silver or CPs to get out of PK jail. (New PK Rules) However, if you let someone bring your DBs in, he/she may be killed and drop them.

To prevent this, we strongly recommend that you use the NPCs we have added in PK Jail. You can credit DBs to the character who is in PK Jail, claim them from the Prize NPC (36, 66) and then exchange them for CPs from the CP Admin (31, 68).