US President Barack Obama has told a memorial service for 13 people shot dead by a gunman at an army base killed there was no justification for such killings.
Army major Nidal Malik Hasan, who is accused of carrying out the massacre, was shot by police and remains in hospital, the BBC reports.
Mr Obama met relatives of those killed at Fort Hood in Texas, before leading the memorial service.
The president said no faith justified the "murderous and craven acts".
He also praised the bravery of those who had helped victims in the "terrible minutes during the attack".
Meanwhile, the Senate Homeland Security Committee announced it would hold a full investigation into the attacks, starting with a public hearing next week.
Senator Joe Lieberman, who chairs the committee, said investigators would seek to determine Maj Hasan's motives and whether the government missed warning signs.
The BBC reports the FBI noticed Major Nidal Hasan in December as part of an unrelated inquiry by the Joint Terrorism Task Force, but did not raise concerns.
Investigators say his communications with another person were in line with his job as an army psychiatrist.