Anton O'Mara's Gang is a group of criminals led by Anton. Anton is the son of Seamus O'Mara, a weapons dealer.

Subway Confrontation

The gang, led by Anton, entered a subway car, and attempted to start a fight with two other passengers. Anton showed them his weapon, and the two passengers left. Noticing an apparently sleeping John Reese, Anton attempted to steal his bottle of alcohol, with Reese resisting. A fight soon broke out, with Reese easily defeating all members. The two sides were taken into custody at the police station, with Reese being released by a lawyer, sent by Finch. (“Pilot”)

Weapons Dealing

After being released, Anton, along with his father, inspected a delivery of weapons. Reese, who tracked this meeting using Finch's surveillance system, appeared at the meeting. With all guns pulled on him, Reese once again defeated all the attendants with a single gun, wounding all but Anton. (“Pilot”)