FORT HOOD, Texas » Army Maj. Nidal Hasan was convicted today in the 2009 shooting rampage at Fort Hood, a shocking assault against American troops at home by one of their own who said he opened fire on fellow soldiers to protect Muslim insurgents abroad.

The Army psychiatrist acknowledged carrying out the attack in a crowded waiting room where unarmed troops were making final preparations to deploy to Afghanistan and Iraq. Thirteen people were killed and more than 30 wounded.

Because Hasan never denied his actions, the court-martial was always less about a conviction than it was about ensuring he received the death penalty. From the beginning of the case, the federal government has sought to execute Hasan, believing that any sentence short of a lethal injection would deprive the military and the families of the dead of the justice they have sought for nearly four years.

A jury of 13 high-ranking military officers reached a unanimous guilty verdict in about seven hours. Hasan had no visible reaction as the verdict was read. In the next phase of the trial, they must all agree to give Hasan the death penalty before he can be sent to the military’s death row, which has just five other prisoners. If they do not agree, the 42-year-old could spend the rest of his life in prison.

Hasan, a Virginia-born Muslim, said the attack was a jihad against U.S. wars in Iraq and Afghanistan. He bristled when the trial judge, Col. Tara Osborn, suggested the shooting rampage could have been avoided were it not for a spontaneous flash of anger.

"It wasn’t done under the heat of sudden passion," Hasan said before jurors began deliberating. "There was adequate provocation — that these were deploying soldiers that were going to engage in an illegal war."

All but one of the dead were soldiers, including a pregnant private who curled on the floor and pleaded for her baby’s life.

The sentencing phase is expected to begin with more testimony from survivors of the attack inside an Army medical center where soldiers were waiting in long lines to receive immunizations and medical clearance for deployment.

About 50 soldiers and civilians testified of hearing someone scream "Allahu akbar!" — Arabic for "God is great!" — and seeing a man in Army camouflage open fire. Many identified Hasan as the shooter and recalled his handgun’s red and green laser sights piercing a room made dark with gun smoke.

Hasan, who acted as his own attorney, began the trial by telling jurors he was the gunman. But he said little else over the next three weeks, which convinced his court-appointed standby lawyers that Hasan’s only goal was to get a death sentence.

As the trial progressed, those suspicions grew. The military called nearly 90 witnesses, but Hasan rested his case without calling a single person to testify in his defense and made no closing argument. Yet he leaked documents during the trial to journalists that revealed him telling military mental health workers that he could "still be a martyr" if executed.

Death sentences are rare in the military and trigger automatic appeals that take decades play out. Among the final barriers to execution is authorization from the president. No American soldier has been executed since 1961.

Hasan spent weeks planning the Nov. 5, 2009, attack. His preparation included buying the handgun and videotaping a sales clerk showing him how to change the magazine.

He later plunked down $10 at a gun range outside Austin and asked for pointers on how to reload with speed and precision. An instructor said he told Hasan to practice while watching TV or sitting on his couch with the lights off.

When the time came, Hasan stuffed paper towels in the pockets of his cargo pants to muffle the rattling of extra ammo and avoid arousing suspicion. Soldiers testified that Hasan’s rapid reloading made it all but impossible to stop the shooting. Investigators recovered 146 shell casings inside the medical building and dozens more outside, where Hasan shot at the backs of soldiers fleeing toward the parking lot.

The first person to charge Hasan, a civilian doctor, was shot dead while wielding a chair. Another soldier who ran at him with a table was stopped upon being shot in the hand.

Chief Warrant Officer Christopher Royal saw an opening after hearing the distinct clicking of the gun’s chamber emptying. But he slipped on a puddle of blood while starting a sprint toward Hasan. He was shot in the back.

Tight security blanketed the trial. The courthouse was made into a fortress insulated by a 20-foot cushion of blast-absorbing blockades, plus an outer perimeter of shipping containers stacked three high. A helicopter ferried Hasan back and forth each day. The small courtroom was guarded by soldiers carrying high-powered rifles.

In court, Hasan never played the role of an angry extremist. He didn’t get agitated or raise his voice. He addressed Osborn as "ma’am" and occasionally whispered "thank you" when prosecutors, in accordance with the rules of admitting evidence, handed Hasan red pill bottles that rattled with bullet fragments removed from those who were shot.

His muted presence was a contrast to the spectacles staged by other unapologetic jihadists in U.S. courts. Terrorist conspirator Zacarias Moussaoui disrupted his 2006 sentencing for the Sept. 11 attacks multiple times with outbursts, was ejected several times and once proclaimed, "I am al-Qaida!"

Prosecutors never charged Hasan as a terrorist — an omission that still galls family members of the slain and survivors, some of whom have sued the U.S. government over missing the warning signs of Hasan’s views before the attack.

Associated Press reporter John Mone contributed to this report.