Duvaine

Duvaine was a devout Catholic working with Michael Shalhoub to take down the current, and in their view corrupt, version of Catholicism through killing the Pope.

Trinity
Duvaine was part of Michael's plan to kill the Pope. When the original plan failed, however, Duvaine, along with several other Catholics working alongside Michael, killed Giancarlo's guards and impersonated them. When Jack Bauer and Harry Driscoll identified Mark Gelson as he was about to kill the Pope, a gunfight ensued. Duvaine was one of Michael's men killed during the gunfight, according to Pembrooke.