James Wheeler is an Assistant District Attorney, and Diane Hansen's ex-boyfriend and co-counselor. After Diane Hansen's ring framed Lawrence Pope, Wheeler started to suspect Hansen's involvement in the crime. He attempted to meet with her privately, and even broke into her office to print details regarding Pope's younger brother, Michael Pope, who was the only witness to the crime his brother was framed for. Following Lawrence Pope's murder, Hansen tasked Stills and his men to murder Wheeler. Bringing along an ex-con Wheeler put away to frame for the murder, Stills was notified that Wheeler's son was with him. John Reese, who at first believed Hansen was in danger yet later learned of Wheeler's upcoming attack, intervened and held one of Stills' men hostage. Wheeler and his son left the building with no knowledge of their intended murder. In court the next day, Reese planted a recording of Hansen ordering Stills to "take care of Wheeler," with the entire court, including Wheeler, learning of her true nature.
Lawrence Pope is a drug dealer and the older brother of Michael Pope, who fell victim to Detective Stills and a group of corrupt officers who robbed him and his friends of their drugs and money, killing five of them and framing Lawrence for the murders. Lawrence was not present at the time of the murders but his brother was and in order to protect him he accepted the blame and was prosecuted by Hansen for the murders. Hansen figured out that Lawrence was not present and that he was trying to protect his younger brother. In a fit of rage, Lawrence attacked Hansen during a jailhouse interview and had to be restrained. Hansen orchestrated to have Lawrence murdered while in jail where he was viciously stabbed to death.
Michael Pope is Lawrence Pope's younger brother. He witnessed a crime committed by Stills and his crew of dirty cops which framed his brother but was able to escape. The dirty cops were actively hunting him down in order to silence him. While monitoring communications between Stills and Diane Hansen, Finch and Reese realized that Michael was in mortal danger and Reese tried to reach out to him but Michael was too scared and ran off. Still's and his gang captured Michael and took him to be murdered when a grenade launcher toting Reese intervened and saved him.
Henry Wheeler is James Wheeler's son. On his way outside for baseball practice with his father, Henry dropped the ball. When he went to fetch it, Henry saw John Reese, who was there to prevent a corrupt police officer from killing Henry's father. With a smile, Henry grabbed the ball and rejoined his father, neither of them the wiser.
Doyle is a corrupt police officer, and a member of HR. Being a part of Still's ring, Doyle took part in the crimes organized by Diane Hansen, and the framing of innocent civilians. He took part in the plot to kidnap and murder Michael Pope, which was thwarted by John Reese. Doyle was later part of the mission to murder James Wheeler, Hansen's ex-boyfriend and co-Assistant District Attorney, who suspected her of shady business. Doyle was in charge of spying on Wheeler, and warned Stills of the presence of Wheeler's son, Henry. During a stand-off between Stills and Reese, Doyle attempted to attack Reese from behind, but Reese was quick enough to shoot him in the leg. Reese instructed Azarello to take him to the hospital. It is assumed that Doyle was arrested by Carter.
Anton O'Mara is a criminal and a weapons dealer, and the son of Seamus O'Mara who both are involved in the criminal underworld. Leading his own group of criminals, Anton was part of his father weapons business. One night on a subway, Anton confronted two weapon-wielding passengers, though they soon departed after seeing Anton's attitude. Anton noticed a sleeping bearded passenger, holding a bottle of alcohol, and attempted to steal it. The passenger refused to cooperate, and Anton's gang members tried to attack him, though the passenger easily defeated the entire gang. A few days later, Anton, his gang and his father met with a gun supplier to purchase arms. Reese, who tracked them using multi-camera surveillance and database, arrived. He addressed Anton by name, and then kneecapped all of the people present except for Anton. After taking the weapons he wanted, Reese left.
Seamus O'Mara is Anton O'Mara's father and the apparent leader of a gang involved in weapons trafficking. He and Anton were inspecting a new weapons shipment when Reese tracked them down. O'Mara and his men drew their guns on Reese, but he defeated them all with a single gun, wounding all but Anton. Reese then took an assortment of their weapons and left.