Who is Sgt. Roach?
Roach is part of Task Force 141 under the command of Capt. John "Soap" MacTavish. Roach takes the place that Soap had during the first Modern Warfare game as "the new guy" or "rookie". Sanderson is also a member of the 22nd British SAS regiment.
Modern Warfare 2
Following the attack in the Russian airport by Vladimir Makarov, Task Force 141 follows a tip to the slums of Rio De Janeiro to find one of his contacts. Early on in the mission, Roach takes down an associate of Alejandro Rojas, Faust. After capturing Rojas, Task Force 141 flee from the favela to a landing zone where, after some resistance, they are picked up by Nikolai in a Pave Low helicopter.
Following the revelation that the Russian's defense is reliant on an oil rig based security system, Roach travels with Task Force 141 to storm a rig and rescue hostages on board, before carrying on to an old Russian gulag to release Prisoner #627. Upon his release, Price plans his own plot to take control of a Russian nuclear submarine and use a nuke to cause an EMP blast above Washington D.C., disabling the Russian Air superiority.
With only two possible safehouses left, Ghost and Roach head to the Caucasus Mountains but instead of finding Makarov, they find a safehouse filled with weapons and computers full of valuable information. Once the safehouse has been stormed, Ghost and Roach return to the pick up point where General Shepherd is waiting for them. He asks if they have the data, and after Ghost says they do, he shoots them both and burns the bodies.