Maj. Nidal Hasan, the Army psychiatrist who four years ago turned his gun on fellow soldiers at Fort Hood, Texas, has been convicted of murder.
He was found guilty on all counts, including premeditated murder.
Hasan, 42, faces the death penalty. If he is executed, he would become the first person the U.S. military has put to death in more than 50 years.
A 13-member panel, or jury, of high-ranking officers voted unanimously to convict Hasan, 42, for killing 13 people and injuring 31 others in 2009.
As the verdict was read, Hasan had no visible reaction.
Similarly, there was no outcry from the audience, which included relatives of the victims. Military judge Col. Tara Osborn warned against any outbursts.
Several family members, however, left in tears.
The panel took only about seven hours to convict Hasan, and now turns to sentencing phase of the trial to decide what punishment to recommend.
Prosecutors are expected to call 16 witnesses over two days during the sentencing phase as they move to have Hasan face the death penalty.