- "You sure you want to take care of business?! Your last friend wasn't so lucky!"
- —Oscar threatening the Scarred Raptor Leader(src)
Oscar worked for InGen twelve years prior to the events that unfolded in the first movie. He was hired, along with many other mercenaries, to "remove" the native people on Isla Nublar, so that the site on the island could be converted into an amusement park.
Oscar murdered some of the indigenous people who tried to fight back, causing Nima to hate and despise him. He did, however, seem to feel remorse for his misdeeds, and so to remind himself of those people who either died for him or were killed by him, Oscar had a series of tattoos grafted onto his left arm; the gravestones symbolizing his friends who died for him and the skulls symbolizing the enemies he had killed.
Oscar and his young comrade Billy Yoder, arrive by helicopter to Isla Nublar to help rescue personnel stuck on the island. After they found the survivors, they had many confrontations with the many carnivores that roamed the island. Oscar was a skilled and brave fighter, evidented through a single one-to-one combat with a Velociraptor and succeeding in killing it in and scarring the alpha-female. He also seemed to have good knowledge of the names of the dinosaurs on the island, seen when correcting Billy Yoder from calling a Pteranodon a Pterodactyl.
The Velociraptors pushed the remaining survivors into a corner. Oscar managed to reach the control panel and hit the button to open the door for the survivors to escape, but in turn, was devoured and clawed by the Velociraptors.