John Galligan, Hasan's lead attorney, said last week he is still waiting for information from the government about what the Army knew about Hasan prior to the the November 2009 shootings and what contact Hasan had with Muslim radicals overseas before considering offering evidence at the Article 32 hearing that resumes Monday, CNN reported.
"I've been asking for this for a year," Galligan told CNN in a telephone interview. "I feel like I've been misled by the government."
The Article 32 hearing is to determine whether to proceed to a court-martial. Since the hearing began last month, the prosecution offered more than 50 witnesses in presenting their theory of how Nidal killed 13 people and wounded 32 others in the shooting.
Without the government-held information, Galligan said he cannot mount an effective defense. Officials blamed delays in releasing the information on security concerns and the need to protect classified information.
Congress also has requested the information.
The government information "is relevant, clearly relevant, for us," Galligan told CNN. "Without that I'm effectively ambushed and limited to what I can do in presenting a defense."
The hearing was in recess to mark the one-year anniversary of the massacre.
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