A report into the killing of 13 people at an American army base has concluded procedures dealing with internal threats are outdated and ineffective.
The report identifies numerous "red flags" over the behaviour of Major Nadal Hasan leading up to the killings at the Fort Hood base in Texas in November.
A number of army officers could now face disciplinary action.
Defence Secretary Robert Gates says there were institutional failings in dealing with internal threats. He said: "The department is burdened by 20th Century attitudes rooted in the Cold War."
Mr Gates said army superiors must be "attuned to personnel who may pose a danger".
Major Hasan, 39, an American-born Muslim, will be tried in a military court.
The BBC reports it has not yet been confirmed whether the death penalty will be sought.