Carlos is an operative of the U.B.C.S., in charge of heavy weapons, security and mission backup. This South American native was sent to Raccoon City during the outbreak for what he believed was a rescue mission.

Carlos ran into Jill Valentine, and together they searched for a way out of the city. The naïve Carlos began to realize that his unit was not sent for rescue purposes but to collect combat data for Umbrella, and that his commanding officer, Nicholai Ginovaef, is actually there to make sure none of the team makes it out alive.

Carlos and Jill are hunted throughout Raccoon City by the Nemesis, which managed to infect Jill with the T-virus. Carlos takes it upon himself to find a cure for Jill, travelling to the Raccoon City Hospital where he finds a vaccine. With Jill back at full health the two kill Nicholai, destroy the Nemesis and escape Raccoon City before it is nuked.

Carlos now knows that his former employer is responsible for the deaths of millions of lives. Since the outbreak, his whereabouts are unknown.