Duff

Duff was a security guard from Department of Homeland Security who stationed at CTU Los Angeles during Day 5.

Day 5
Duff belonged to the Homeland Security takeover team led by Karen Hayes that aimed to replace the CTU personnel killed in the Sentox nerve gas attack happened few hours ago and eventually abosrbed CTU into DHS.

A few minutes after 9:00 p.m, Bill Buchanan instructed Duff and Smith to take Audrey Raines into custody after suspect Collette Stenger named Audrey as her source of information. Smith and Duff briefly stood guard inside the interrogation room while a CTU worker wheeled the interrogation equipment on a cart and connected some of the devices onto Audrey.

After talking with Audrey, Jack convinced that Audrey was framed and took her out of the interrogation room. Rick Burke tasered an uncooperative Jack while two other guards handcuffed him. Audrey was taken back to the holding room again by Duff and Smith.