Riley Cavanaugh is an enforcer for the Irish mob who worked for his boss, George Massey. He was ordered by George to kill Sean Delaney because he was stealing from him and was then sent to keep an eye on his widow Annie but he fell in love with her. When George found out about their relationship, he put a hit on them. He was able to save Annie and kill George with help from Reese, but was himself killed by one of the bounty hunters hired by George. By saving Annie he was able to redeem himself in the eyes of both Reese and Finch and was thus able to prove that people can change.
- Finch tells Reese that Riley is Bad Code, although he changes his opinion after Riley's death