Jason

Jason is the former captain of the U.S. Army special forces team Mad Dogs, after a traumatic event happened on the war torn country Penamstan. He then becomes a federal agent serving alongside Leon Scott Kennedy under President Graham.

Nothing is currently known about Jason and his life. But in the year 2000, he leads a squad named Mad Dogs, who were in the battleground, he and the others refused orders from the command center to stand their ground and instead went to save survivors of the helicopter crash belonging to the U.S. special forces who were intervening in the Penamstan civil war. However, the special forces were already annihilated and his squad was forced to escape to survive but not before seeing the supposedly dead special forces moving erratically.

Six years later, a hacking incident occurs on a top secret White House file. Four agents, including Leon and himself are invited to the White House to investigate the incident.

(Source: Resident Evil Wiki)