Gabriel is a kidnapper from Argentina who kidnapped Alan Hayes to use as leverage against Apex Industries.
Gabriel is of Argentine descent and was born and raised in Argentina. He was educated in medicine and eventually became a doctor in his hometown. Gabriel was married and had Eva with his wife.
When Apex Industries arrived to hire workers to build computer chips, Gabriel's hometown's governor praised it as a step in progress for the future. Unbeknownst to the town's citizens however, Apex Industries was dumping chemical waste into the town's water table. As a result, many of the town's people became ill with headaches and fever. The adults eventually overcame their illnesses, but the children could not adapt to these new diseases. Gabriel did what he could do to save them, but many of the children died, including his own daughter, Eva. This event broke Gabriel, causing him to leave to train with Colombian rebels for two years. In exchange for their military expertise, Gabriel would teach them field medicine.
Prior to his meeting with Fiona Glenanne, Gabriel kidnapped Apex Industries scientist Alan King from his home in front of his family.
Gabriel ordered one of his men to fill out an empty slot for the next kidnapping operation to come. Coleman hired Fiona for $20,000 (half up front, half upon completion). He escorted Fiona to Gabriel's mansion. At this point, Gabriel tested her immediately by checking her passport found in her apartment. Michael and Sam worked quickly to forge a visa in her passport showing she visited Madrid, Spain in 2006. Gabriel was satisfied and allowed her to leave.
The next day, Coleman was caught messing around with a woman. Feeling that Coleman compromised the upcoming operation, Gabriel arranged for his execution. He updated Fiona about Coleman after testing her a second time. Sam arrived at the house and distracted him long enough for Fiona to investigate the padlocked room.
After meeting with Sam, Gabriel took Fiona out for a car drive. Realizing that Fiona broke into his office and investigated him, Gabriel revealed his past. He recounted about how Apex Industries was responsible for negligently dumping their chemical waste into his home town's water table, causing a lot of his people to grow sick. The adults eventually got well, but a lot of children died including his daughter Eva. He held Fiona up at gunpoint and was about to execute her until Fiona honestly answered the question he had previously asked her. She revealed that the first thing she thought of after seeing her sister Claire killed by an English soldier was the bread pudding she had made her as an apology for a fight they had earlier that day, and how upset she was knowing that her sister had died angry with her. Gabriel relented and allowed Fiona to live.
At a restaurant, Gabriel discussed his plans to Fiona about Dr. King's role in his latest kidnapping operation. He wanted Fiona to distract Gabriel's latest target, the Head Counsel of Apex Industries so they can use him as leverage to force the company out of Argentina. Once the kidnapping was completed, Gabriel would execute Dr. King in front of the Counsel so Apex would open their ears to his demands.
On the day of the kidnapping operation, Michael Westen arrived at the restaurant (thanks to a GPS device rigged by Sam Axe and activated by Fiona) to set a grease fire in the kitchen. The fire triggered a fire alarm, forcing everyone including the Head Counsel to evacuate the restaurant and blow Gabriel's operation.
In a last ditch effort to cover his tracks, Gabriel and Fiona raced to execute Dr. King. Fiona used Gabriel's paranoid history to distract him long enough to take Dr. King out of the warehouse before subduing Gabriel. Fiona locked him in the warehouse cage while Gabriel cursed her for dishonoring him and her sister. As a last act of defiance from serving time, Gabriel started a fire, causing the warehouse to explode in mere moments. Michael and Sam arrive in time to pull Dr. King and Gabriel to safety.
After the rescue, Gabriel was taken into custody for his actions. However, his efforts were not in vain. Fiona acted on his good intentions to get Dr. King to blow the whistle on his company for their actions in Argentina.