John P Gaffaney was 56 and a psychiatric nurse and Army Reserve officer killed during the Fort Hood shooting on November 5, 2009. He was at the Soldier Readiness Center preparing for deployment to Iraq when Maj. Nidal Hasan opened fire, an attack that killed 13 people and wounded more than 30.

Accounts say Capt. Gaffaney acted to stop the shooter — either picking up a chair and throwing it at Hasan or physically rushing him across the room — and was mortally wounded during those efforts. He later received the Soldier’s Medal posthumously. The Army Reserve center in Garden Grove, California, was later named in his honor.

Who knew Capt. Gaffaney or has information about his actions that day?