Brennan

Brennan is the head of the unit reporting to Christopher Henderson that was supposed to take out Wayne Palmer as he was trying to get to the the Presidental retreat. He was foiled when Palmer was able to get ahold of one of his men's weapons and Aaron Pierce rescued Palmer.

He was used again by Henderson to take out Evelyn Martin when she was trying to get her daughter Amy (who was kidnapped by Henderson). Before he could complete his mission, Jack Bauer slit his throat and used the rifle to take out several of Henderson's men.