From Halopedia, the Halo wiki
Dominique was a short man, and therefore very nimble. He was known to have a very athletic figure and to rarely smile; always business. His Commanding Officer, Jacob Keyes, noted this and approved of the fact that he could rely on Dominique in any type of situation.
Early Military Career
Iroquois and Autumn
In 2552, Dominique served under Keyes aboard the UNSC Iroquois. By the Battle of Sigma Octanus IV, Dominique was the Iroquois's communications officer  and later transferred to Keyes' subsequent command, the UNSC Pillar of Autumn as part of the command crew.
Dominique was present at the Battle of Installation 04, and he was most likely killed when the Covenant attacked the Pillar of Autumn, though he is not mentioned.
List of appearances