(Covers information from Anderson's universe)
Otto was a member of Claire Redfield's convoy. His role was driving the school bus.
The school bus portion of the convoy appears to be the vehicle responsible for the transportation of the younger children, and is fitted with bunks as well. In Resident Evil: Extinction, Otto is shown passing out food to the convoy, being able to identify the contents of the cans by merely shaking the object. Claire notices this, and asks him how does he do that, with him simply responding "It's just one of my skills." and calling it a "dying art".
Shortly after, when infected crows attacked the convoy, he attempts to drive the school bus away, but the windshield's view is obstructed by the birds and he crashes the vehicle into a pole. He and Nurse Betty stay behind to hold up the broken windshield to block the birds from entering the bus, allowing the others to leave as they stayed behind. Eventually, the crows are able to get through, pushing Otto out of the way and outside the bus, landing helplessly on the ground where he is pecked to his death.