Gabril was a citizen on Aguerra Prime. He saw Dark Athena landing and how the mercenaries poured out of it. When the mercenaries swept the streets for survivors he holed up in the Refinery communication room, and tried to get a signal to neighboring systems. Once Riddick answered his call, Gabril asked him to destroy signal jammers that Dark Athena mercenaries set up after the gas attack. It's unknown if Riddick helped him or not. He was killed by Spinner