John DeMarco (Batman Arkham Origins)

First Appearance: Batman Arkham Origins

John DeMarco was a member of the G.C.P.D's S.W.A.T team. He had been imprisoned after being convicted of drug use.

Prior to Christmas Eve, the G.C.P.D's I.A.D was planning to investigate his unit for corruption.  He discovered that one of his team mates, Nate Ramo was planning a plea that would supply evidnece on the entire team for corruption, which semented evidence that the I.A.D could not find. He decided to kill Ramo to silence him.

On Christmas Eve, DeMarco committed hit and run, however lost control of his car in the blizzard and crashed near the G.C.P.D building. He fled the scene before he was discovered and searched Ramo's house to find anything that would incriminate him.

Batman later learns of DeMarco's involvement in the murder, due to the paint residue found at the scene matching the residue on his car. 

DeMarco meets with the rest of his team, who care more about the fact that they could be found out aboyut corruption rather than the death of their team mate. He was confident that after the I.A.D had finished, the team would be back to work. 

Batman hears all this and interrogates him after defeating the rest of S.W.AT. He tells DeMarco as he addmitted to the murder, he would be given a life imprisonment. But DeMarco says that evidence tends to go missing in the G.C.P.D. Batman tells him that this evidence won't go missing, sending the G.C.P.D evidence of the murder and a taped confession which Alfred had recorded during the interrogation.