Meanwhile, President Barack Obama ordered a review of all intelligence related to Maj. Nidal Malik Hasan, 39, and whether the information was properly shared and acted upon within government agencies.
Additional charges may also be filed against Hasan, said Chris Grey, spokesman for the Army's Criminal Investigation Command. "We have a duty and obligation to protect the constitutional rights of everyone involved," Grey said during a press conference at Fort Hood.
Hasan is accused of opening fire at Fort Hood's crowded Soldiers Readiness Processing Center, where troops get medical checkups before deploying abroad. The rampage is described as one of the worst mass shootings on an American military base.
John Galligan, Hasan's civilian attorney, said his military co-counsel told him that charges were being read to Hasan in the hospital without his lawyers present.
"I don't like it. I feel like I'm being left out of the loop," Galligan said. "I guess it's 13 charges, but I don't like to have to guess in this situation."