Manny is the leader of the Compound guards and is located in the Compound himself, guarding the entrance with a turret and two other guards. He and the other guards always stand ready to snatch any synths crossing with Covenant, and put them into cells in the Compound.
During Human Error, Manny can be persuaded with a difficult speech check to hold fire and lead the Sole Surivor directly to Dr. Roslyn Chambers. During this walk, he'll also briefly talk with Tach Blythe. When Roslyn is attacked, he'll turn hostile.