Thirteen people were shot dead on the Fort Hood base.
A review of US Army and Pentagon policies has been ordered by the defence secretary in the wake of a shooting at a military base.
The review will include Pentagon medical and personnel programmes, and US military base security.
Defence Secretary Robert Gates appointed a former Army secretary and an ex-Navy chief to report in 45 days.
The review is in addition to others into the Fort Hood shooting in which 13 people were killed.
Army psychiatrist Nidal Malik Hasan, 39, was shot by police during the incident on 5 November, and remains in hospital. He has been charged with 13 counts of murder.
"The shootings at Fort Hood raise a number of troubling questions that demand complete but prompt answers," Mr Gates said at the Pentagon.
He said the review would look at ways to ensure the safety of military members and their families.
It would also look at any gaps in identifying personnel who could pose threats to others.
"We do not enter this process with any preconceived notions," he said, according to AFP news agency.
"However, it is prudent to determine immediately whether there are internal weaknesses or procedural shortcomings in the department that could make us vulnerable in the future."
Former US Army secretary Togo West and former chief of naval operations, Admiral Vernon Clark will oversee the review.
US President Barack Obama has already ordered a review of the way intelligence agencies handled information about the major.
US intelligence authorities revealed they knew Maj Hasan had been in contact with a cleric sympathetic to al-Qaeda.
An FBI-led task force monitoring the e-mail of Yemen-based US cleric Anwar al-Awlaki said he had communicated with Maj Hasan - a US-born Muslim and army psychiatrist - on 10 to 20 occasions.
However, it was decided that further investigation was not needed, as the content of the messages did not advocate or threaten violence.