Brian F. O’Byrne is an Irish actor who played “Bert Pierce” alongside Kate Winslet, Evan Rachel Wood, and Guy Pearce in the HBO miniseries Mildred Pierce. He has appeared as “Aaron Stark” on ABC’s FlashForward and “Colin” on the television series Brotherhood. O’Byrne was “Father Horvak” in Million Dollar Baby and had roles in Bandits, Before the Devil Knows You’re Dead, The International, and No Reservations. He is also known as "Detective Reg Duffy" on NBC's Prime Suspect.