An Army psychiatrist accused of one of the worst mass shootings in U.S. history told jurors that "evidence will clearly show" that he was the gunman responsible for the rampage that traumatized the Fort Hood military base in Texas nearly four years ago.
But Maj. Nidal Malik Hasan, who is representing himself in the long-awaited court-martial, also cautioned that the evidence wouldn't tell the entire story.
"The evidence will clearly show that I am the shooter," Hasan, an American-born Muslim accused of killing 13 soldiers and wounding 32 others on Nov. 5, 2009, told jurors in a less than two-minute-long opening statement, reported The Associated Press. However, he added, "The evidence presented during the trial will only show one side."
The court-martial began under heavy security on Tuesday. A row of shipping freight containers, stacked three high, created a makeshift fence around the courthouse on the first day of the trial, which is expected to last several weeks, according to The AP. Guards with long assault rifles stood watch outside the courthouse.
Many of 32 who were wounded will appear on the witness stand during the trial, facing the man accused of wounding them.
Hasan is acting as his own defense attorney at the trial after twice dismissing his legal team. He told jurors evidence will also show "that we are imperfect Muslims trying to establish the perfect religion... I apologize for any mistakes I made in this endeavor," reported The AP.
Military prosecutor Col. Steve Henricks said prosecutors would show that Hasan picked the date of the attack for specific reasons in his opening statement, although he didn't reveal more details immediately, The AP reported.
Henricks also argued that Hasan chose a time when the large hall where he opened fire on the base would be most crowded, and seemed to mostly spare civilians, specifically targeting soldiers.
"He then yelled 'Allahu akbar!' and opened fire on unarmed, unsuspecting and defenseless soldiers," Henricks told the jury, using the Arabic phrase for "God is great!"
The 42-year-old Hasan, shot by a civilian police officer and paralyzed from the waist down after the rampage, is confined to a wheelchair.
He has admitted to the 2009 rampage, but was prohibited by a military judge from entering a guilty plea because prosecutors are pursuing the death penalty.
Hassan faces lethal injection if convicted of 13 counts of premeditated murder and 32 counts of attempted murder. A unanimous guilty verdict is required for execution but even that decision would likely be subject to years — potentially decades — of complex appeals, according to Reuters.
Hasan's trial was initially slated to begin more than a year and a half ago, but legal quagmires have repeatedly delayed it.
The first judge in the case was ordered to be removed because of an appearance of bias. Hasan has also fought with the court to represent himself and to sport his beard, a violation of the Army's grooming standards, which he says he is doing as an expression of his religion.
He faces a panel of 13 senior Army officers — including nine colonels, three lieutenant colonels, and one major.
One of the wounded men who is testifying, Staff Sgt. Alonzo Lunsford, told The AP that the prospect of confronting Hasan face to face doesn't elicit fear in him.
"I'm not going to dread anything. That's a sign of fear," Lunsford said. "That man strikes no fear in my heart. He strikes no fear in my family. What he did to me was bad. But the biggest mistake that he made was I survived. So he will see me again."
But another survivor, Staff Sgt. Shawn Manning, feels differently.
"I have to keep my composure and not go after the guy," Manning, a mental health specialist who was preparing to deploy to Afghanistan with Hasan when he was wounded, told The AP. "I'm not afraid of him, obviously. He's a paralyzed guy in a wheelchair, but it's sickening that he's still living and breathing."
A helicopter transports Hasan nearly every day between Bell County Jail, where he is being held, to the Fort Hood base, and he lives under the watch of a private guard for at least 12 hours each day — all on the dime of the U.S. Army and American taxpayers, according to NBCDFW.com.
The daily helicopter rides are necessary because driving Hasan by car creates security concerns for the jail, NBCDFW.com reported.
But victims of the rampage told NBCDFW.com that the special treatment he receives doesn't match up with what they have gotten since the shooting.
Staff Sgt. Josh Berry, one of the victims injured in the shooting, committed suicide on Feb. 13, 2013, after years of battling post-traumatic stress caused by the massacre, his family told the station.
"He felt there were more considerations that were being given to the shooter that weren’t being given to the victims and he couldn’t understand," said Howard Berry, Josh’s father.
NBC's Daniel Arkin contributed to this report. The Associated Press also contributed.
This article was first published on NBCNews.com here.