Quigley was a federal agent from the U.S. Treasury.
Before Season 3Edit
The U.S. Treasury was worried with how the Armenian Mafia was shipping U.S. currency overseas. To stop this, Quigley's office instituted a sting operation. They convinced a businessman in San José, who was being extorted by the Armenians, to insert $50,000 in marked, traceable bills into his payment to the Mafia. Their plan was to track the Armenian money and find out what banks were handling their transactions. However, in three months, not a single dollar from the stash was used.
Quigley was notified by a colleague in the FBI about the Barn's investigation on Armin Chorekian, the Armenian Money Train, and four related murders. He then went to the Barn and met with Captain David Aceveda and Detective Dutch Wagenbach. After informing them of their operation, Quigley agreed to help them track the money and find the murderers.
Quigley brought the list of marked bills to Dutch and Aceveda and told them that the money would probably be spent where it was stolen. He then asked if they had any luck with finding Margos Dezerian. Dutch told him the troubles he was facing with international authorities in Greece, who were requesting someone other than a detective to proceed against Margos. Dutch then asked Quigley if he had any contacts in Washington, DC and Quigley told him he might be able to help.