Military psychiatrist Maj. Nidal Malik Hasan, 39, shot and killed 13 people on Nov. 5 News at Fort Hood, Texas and injured 31 others.

After being first reported dead as a result of gunfire with an officer, Hasan is unconscious and hospitalized, NPR is reporting.

It was first believed that at least three people were involved in the shooting, but police now say there was only one, Hasan.

Hasan, a U.S.-born Muslim, was a psychiatrist at Walter Reed Army Medical Center for six years before being sent to Texas in July. Reports say he was upset about an upcoming deployment overseas.

Fort Hood, located near Killeen, Texas with about 40,000 troops, is home to the Army’s 1st Cavalry Division and elements of the 4th Infantry Division, as well as the 3rd Armored Cavalry Regiment and the 13th Corps Support Command.