FORT HOOD, Texas — The soldier who killed three people before committing suicide in an attack on the same Texas military base where more than a dozen people were slain in 2009 had shown no recent risks of violence, authorities said today.

The shooter, identified as Ivan Lopez by Texas Rep. Michael McCaul, chairman of the House Homeland Security Committee, opened fire Fort Hood on Wednesday afternoon. He wounded more than a dozen others.

Military officials declined to formally identify the gunman, an enlisted soldier with the rank of specialist, by name until his family members had been officially notified.

But Army Secretary John McHugh said the soldier saw no combat during a four-month deployment to Iraq as a truck driver from August to December 2011. A review of his service record showed no Purple Heart, which indicates he never was wounded.

The soldier saw a psychiatrist last month and showed no “sign of any likely violence either to himself or others,” McHugh said. His record shows “no involvement with extremist organizations of any kind.”

He added, “He had a clean record in terms of his behavior.”

Within hours of the Wednesday attack, investigators started looking into whether the soldier had lingering psychological trauma from his time in Iraq. Fort Hood’s senior officer, Lt. Gen. Mark Milley, said the gunman had sought help for depression, anxiety and other problems, and was taking medication.

Among the possibilities investigators were exploring was whether a fight or argument on the base triggered the attack.