Brigitte Woosley / AP
Maj. Nidal Malik Hasan, left, and presiding judge Tara Osborn look on Tuesday during Hasan's court-martial at Fort Hood, Texas.
The prosecution rested Tuesday in the court-martial of Army Maj. Nidal Hasan, who could face the death penalty if he's convicted in a shooting spree that killed 13 people at Fort Hood, Texas, in 2009.
Hasan, a military psychiatrist who is representing himself, indicated that he might not offer any defense when he gets his turn Wednesday.
A U.S.-born Muslim, Hasan has admitted in court that he carried out the shootings, which wounded more than 30 other people in November 2009.
Hasan declined Tuesday to ask Col. Tara Osborn, the military judge hearing the case, for a directed verdict of not guilty, a standard motion once prosecutors have closed their case.
And he told Osborn that he didn't plan to call an expert in religious conversion to testify on his behalf, even though the expert is listed as a defense witness.
By contrast, military prosecutors called almost 90 witnesses to detail the carnage at a medical facility at the Army post in Killeen, in central Texas.
One of the last was Steven Bennett, a photographer who was taking pictures at a graduation ceremony at Fort Hood on the day of the shootings.
Bennett, who testified that he was unaware of the shootings elsewhere on the base, took pictures of the gunman as he prowled the facility.
"I saw an individual acting suspicious, very strangely," Bennett testified Tuesday. "He was checking the doors of the building. I started taking photos of this person. He was very agitated, frantic. He seemed unnatural."
Watch US News crime videos on NBCNews.com
Bennett told the 13 military jurors that he talked briefly with Hasan, who he said told him his weapon "was a paintball gun and that this was a training exercise."
"He disappeared in between some buildings, and I heard more gunshots," Bennett said. "I thought I'd better take photos in case someone needed them later."
Prosecutors entered several photos showing the man — whom Bennett identified in court as Hasan — walking as people ran from the scene.
Another photo showed the gunman on the ground after a shootout with police. Hasan was shot and is paralyzed from the waist down.
The photos haven't been made public.
Hasan has said he changed sides to fight against what he considered a war on Islam. The New York Times reported Tuesday that in emailed messages to his superiors a few days before the shootings, he raised concerns about the actions of some of the soldiers he was evaluating — messages that could have raised red flags about his state of mind.
In the emails, which The Times said it was given at Hasan's request, Hasan wrote that he was disturbed by three cases involving soldiers' actions in Iraq and asked Army legal advisers for advice.
"I think I need a lot of reassurance for the first few times I come across these," Hasan wrote in one of the messages. Below his signature, he added a quotation from the Koran, The Times said: "All praises and thanks go to Allah, the Cherisher and Sustainer of all the worlds."
The Army never fully investigated his concerns, The Times reported.
First published August 20 2013, 3:07 PM