Captain Montressor is a driven, fiercely competitive woman who demands nothing but the best from herself and those around her. Her subordinates privately call her the Monster for her mercilessly high standards.
Captain Montressor appears to be the commanding officer of the US Army contingent in Trumbull Valley. Sergeant Tan and his squad are under her command. She is also the representative of the US Army to the civilians of Trumbull Valley, often issuing radio instructions such as how to properly dispose of the infected and how to treat cases of Black Fever.
She gives several controversial orders during the course of the game, such as authorizing lethal force against squatters who resist 'lawful' eviction. It also appears that she ultimately pulls her forces out of Trumbull Valley, leaving Sgt. Tan and his squad to fend for themselves.