Counterterrorism and military officials said Monday night that the communications, first intercepted last December as part of an unrelated investigation, were consistent with a research project the psychiatrist was then conducting at Walter Reed Army Medical Center in Washington on post-traumatic stress disorder.
“There was no indication that Major Hasan was planning an imminent attack at all, or that he was directed to do anything,” one senior investigator said. He and the other officials spoke on the condition of anonymity, saying the case was under investigation.
The officials said the Departments of Defense and Justice had decided Major Hasan would be prosecuted in a military court, an indication that investigators believe he acted alone. Government lawyers had said his case might be tried in civilian court if he were believed to have conspired with nonmilitary defendants.
In a statement, the Federal Bureau of Investigation said, “At this point, there is no information to indicate Maj. Nidal Malik Hasan had any co-conspirators or was part of a broader terrorist plot.” The statement concluded that “because the content of the communications was explainable by his research and nothing else was found,” investigators decided “that Major Hasan was not involved in terrorist activities or terrorist planning.”
