Officials at Fort Hood Military base in Texas have praised a civilian policewoman for stopping Thursday's shooting spree that killed 13 people and wounded 31 others.
Fort Hood Spokesman, Colonel John Rossi, told reporters early Friday police woman Kimberly Munley encountered the suspect - Major Nidal Malik Hasan - and exchanged gunfire with him, shooting him four times.
Munley and the rest of the wounded, including the shooter, remain hospitalized.
Fort Hood officials say Hasan, an army psychiatrist, allegedly began firing two handguns inside a building where soldiers were preparing to deploy overseas.
Fort Hood Hospital Commander Colonel Steve Braverman says he worked with Hasan and knew of no problems with him on the job at Fort Hood.
Officials says a motive for the attack remains unclear, but a former co-worker said Hasan was deeply opposed to the U.S. wars in Iraq and Afghanistan.
He says the suspect worked at the base hospital treating soldiers with behavioral problems.
Hasan, a native of Virginia, received his medical degree from a military medical school in 2003. He worked at the Walter Reed Army Medical Center in Washington for six years before being transferred to Fort Hood in July.
Military and civilian personnel at Fort Hood, near Killeen, Texas, will observe a day of mourning Friday to remember all the victims.
In Washington, Mr. Obama called the shooting a "horrific outburst of violence." The president said it was "horrifying" that men and women who serve their country should come under fire on American soil.
Vice President Joe Biden issued a statement saying his thoughts and prayers are with the entire Fort Hood community as it deals with the tragedy.
Fort Hood is one of the largest U.S. Army posts in the world. It has been dealing with the strain of multiple deployments and post-combat stress. Ten Fort Hood soldiers have committed suicide this year.
Fort Hood is located near the town of Killeen, which was the scene of one of the worst mass shootings in U.S. history. In 1991, a man shot and killed 22 people after driving his pickup truck through the window of a cafeteria.