Andrew Carter was a hardened criminal who suffered from paranoid delusions and was a murderer.
Andrew Carter had an extensive criminal record, and had been released from Blackgate Prison in November, with him having to undergo court-mandated therapy sessions. By Christmas Eve, however, Carter had stopped going to the therapy sessions, and sought to join Bane's Henchmen. After presumably being supplied with Venom, Carter underwent an initiation, where he proceeded to throw an air conditioner fan at an unsuspecting victim, who had presumably uncovered sensitive info about Bane's plans that necessitated his death. Upon completing the murder, Carter then was ordered to wait for Bane's arrival before he was to be dispatched on his mission. However, Batman deduced Carter's role in the murder as well as his instability, arrived, knocked out the unit, and interrogated Carter regarding what Bane had planned for him. Carter, however, refused to talk, which resulted in Batman knocking him out and left him to be arrested by the GCPD.