Breakaway IRA Faction

The Breakaway IRA Faction is a fictional terrorist group which is active in Season Six

Background
This is a group of Irish terrorists led by Ian Doyle before and after his time in prison. They follow his commands without question and are willing to kill their own in order to preserve their organization.

Valhalla
They begin their rampage in DC by killing several members of a counter intelligence agency responsible for Ian's transport to prison. It was at this time that the BAU started to investigate these series of killings and eventually found out that they were behind them.