Sullivan
From BioShock Wiki
Sullivan was the head of security for Rapture. He did Ryan's dirty work for him, though often questioned the morality of his orders. He was put in charge of searching for evidence against Fontaine, though none could be found. Sullivan resorted to torture to find information, though this proved largely ineffective as most of Fontaine's men were more afraid of Fontaine than they were of Ryan. After finally taking out Fontaine in a fiery shootout (or so he thought), Sullivan was put on the case of Anna Culpepper, an artist from Fort Frolic who had offended both Ryan and Sander Cohen by making fun of Cohen's role as a propaganda mill.
Finally, Sullivan was asked to have her 'bumped'. He killed her in her apartment while she was taking a bath. Deeply disgusted with what he did, he took a half finished red and black knitted blanket from Culpepper's flat to remind himself of his deed. Later, when Ryan introduced the death penalty, Sullivan threatened to hand in his badge (it is implied he actually did in the audio diary Have My Badge), and it is considered likely that he killed himself in remorse for his deeds. He is probably the corpse in Neptune's Bounty, since the corpse contains one of his audio diaries.
