(CBS News) Thirty-eight-year-old Staff Sgt. Robert Bales arrived at the military prison at Fort Leavenworth, Kan. late Friday night.
He'll face justice in the United States, not in Afghanistan, where he allegedly killed 16 civilians in two villages.
Originally from Ohio, he is a father and decorated war hero.
He touched down in an Air Force cargo jet at Kansas City International Airport under heavy security.
While in custody at Fort Leavenworth, Bales will be held in pre-trial solitary confinement during the investigation. He'll undergo an extensive physical and psychological exam.
In his hometown of Lake Tapps, Wash., neighbors still can't believe the 11-year veteran is accused of mass murder.
"I'm shocked. I'm completely shocked," said Kassie Holland. "He was always happy. Happy guy, full of life. I really wouldn't expect it."
"A good guy, got put in the wrong place at the wrong time," said Paul Wohlberg.
The massacre threatens to undermine the U.S. war effort in Afghanistan.
Court documents show Bales once completed 20 hours of anger management treatment for an assault case that was later dropped.
His attorney says he joined the Army inspired by the horror of 9-11.
During three tours in Iraq, Bales was injured twice - a head injury from a vehicle rollover, and another that required surgery, costing him part of his foot.
His latest tour in Afghanistan was his fourth - a trip he reportedly didn't want to make.
At Fort Lewis-McChord, where Bales' wife and two children are staying for their protection, military officials promised answers. "We have a tradition of doing what's right," said Gen. David M. Rodriguez, the commanding general of the Army Forces Command, "and we'll do it in this situation, too, as we find out and get to the bottom of the situation."
In 2009, Bales spoke with a military publication about a major battle he was part of while serving in Iraq. He said, "I've never been more proud to be part of this unit than that day. ... We discriminated between the bad guys and the noncombatants. ... I think that's the real difference between being an American, as opposed to being a bad guy."
Bales' lawyer is painting him as a victim - a battle-fatigued soldier who had just seen too much.
To see Whit Johnson's report, click on the video in the player above. Also, Eugene Fidell, who teaches military justice at Yale Law School, talked with "CBS This Morning: Saturday" co-host Rebecca Jarvis about what's next in the case. He says its final resolution could take years. To see that discussion, click on the video below: