From Halopedia, the Halo wiki
Corporal Douglas was aboard the UNSC Dark Was the Night, a military cargo tender, around 2552. Some time before the Fall of Reach the ship was attack by Covenant ships and forced to land on the colony of Losing Hand. One year after the crash, a DAV-class light corvette appeared at the edge of the system. Unaware of the end of the war or humanity's alliance with the Sangheili, many colonists and crew assumed they were under attack. At this point the tension between the colonists and the crew boiled over and the colonists marched on the ship. Corporal Douglas reported to the acting captain, Darren Leone, about the colonists' actions.
List of appearances