(Adds testimony of captain wounded in 2009 Fort Hood shooting)
By Karen Brooks
FORT HOOD, Texas, Aug 9 (Reuters) - Captain Brandy Mason was playing a video game on her phone when she looked up and saw a gun pointed at her head.
Like many others who have testified in the court-martial of a U.S. Army psychiatrist who admits shooting dead 13 people and wounding 31 others at a U.S. Army base in November 2009, Mason at first thought it was a training exercise.
Then the shots rang out.
"I continued to hear the gunshots and then something wet splashed across me," Mason said. "I looked at it and thought it was a sim (simulated training) round, paint balls. I wiped it off my phone and ... went to find somewhere else to hide."
Mason followed 15 witnesses who on Thursday offered emotional depictions of gun smoke, screams, blood and chaos with soldier after soldier describing Major Nidal Hasan's attack on a crowded medical facility at Fort Hood, Texas.
Mason hid under a table, still thinking it was an exercise. She peeked out and saw the barrel of the gun once again, she said.
Even after she was shot in the thigh, her mind told her it was a training exercise - until she was carried out by rescuers, Mason said.
"I was seeing blood and saying, 'So that's really my blood?'" Mason testified. "They said, 'yes ma'am.'"
Hasan, a U.S.-born Muslim, told the jury on the opening day of the trial on Tuesday that "I am the shooter" and that he "switched sides" in what he called a U.S. war on Islam.
The shooting spree took place days before Hasan was to be deployed to Afghanistan. The soldiers were unable to fire back because they are prohibited from carrying weapons on base.
Military police eventually shot Hasan, who was paralyzed from the waist down and attends court in a wheelchair.
Prosecutors opted against bringing terrorism charges against Hasan, who is leading his own defense with the help of standby counsel. Those lawyers have told military judge Colonel Clara Osborn they find Hasan's trial strategy "morally repugnant" because they believe he is actively seeking the death penalty instead of life in prison - the only two punishment options should Hasan be found guilty.
Hasan disputed the lawyers' claim he was seeking the death penalty by lethal injection. Prosecutors say he is likely trying to win favor with the jury by declining to contest the facts of the case and instead angle for life in prison.
Despite pre-trial conjecture about the emotional impact of having Hasan cross-examine his victims, Hasan has not questioned any of the victims or rescuers. Instead their accounts have gone uncontested, bombarding the jury with angry tears and terrifying descriptions of the shootings.
Hasan has questioned only two witnesses, neither of whom was at the scene of the attack.
Hasan could face the death penalty if all 13 officers on the jury find him guilty of premeditated murder. The U.S. military has not executed a service member since 1961. (Additional reporting by Lisa Maria Garz and Jana J. Pruet; Editing by Daniel Trotta and Grant McCool)