Joint Base Lewis-McChord, Washington (CNN) -- A military court-martial Thursday found Army Staff Sgt. Calvin Gibbs guilty of murdering three Afghan civilians, illegally cutting off pieces of their corpses to keep as "souvenirs" and planting weapons to make the men appear as if they were Taliban fighters killed in legitimate firefights.
He faces a maximum sentence of life in military prison without parole. The sentencing phase of the trial began immediately after the guilty verdict from the five-member panel was read.
Gibbs is the highest ranking of five soldiers charged with being part of a rogue "kill squad" that targeted civilians. Another seven soldiers also were charged with lesser crimes including abusing drugs, keeping "off the books" weapons and intimidating a fellow soldier not to speak out against the platoon's alleged killings.
Gibbs had pleaded not guilty.
A prosecutor described Gibbs as a "recruiting poster" soldier. But the tall, clean-cut Gibbs and the "kill squad" he was convicted of leading turned into a public-relations nightmare for the military.
"Sgt. Gibbs had a charisma, he had a 'follow me' personality," Maj. Robert Stelle, a prosecutor in the case, told the court in closing arguments Wednesday. "But it was all a bunch of crap, he had his own mission: murder and depravity."
The murders Gibbs is accused of committing took place over a period of five months last year while Gibbs led the 3rd Platoon of the Army¹s 5th Stryker Brigade in Kandahar Province, Afghanistan.
Gibbs' platoon was tasked with patrolling small villages in the area to build relationships with an Afghan population wary of the U.S. presence in their country. Instead, prosecutors said Gibbs and a small group of rogue soldiers allegedly plotted to murder civilians and then planted weapons on them so they appeared to be Taliban attackers.
"Selling a fake engagement as a real engagement, that's what they were doing," Stelle told the court.
In court testimony, Gibbs said he did not execute anyone. Prosecutors said Gibbs participated in the killings of three unarmed civilians: two farmers and a village cleric.
Gibbs said he killed one of the men but he claimed it was in self defense. However, the staff sergeant admitted to ripping and cutting off fingers of all three men he was charged with killing. He kept the body parts, he said, to give to soldiers he favored or to intimidate soldiers he disliked.
"I was numb to the situation," Gibbs told the court about why he taken the body parts. "I wasn't thinking; it's sickening. I am embarrassed."
Gibbs also admitted to posing for photos with bodies against military regulations.
"People wanted to prove they were there," Gibbs replied when asked by his attorney why the soldiers took the photos. The Army later apologized after the photos were leaked to the press.
Gibbs appeared shocked after the verdict was read and his wife, Army Spec. Chelsy Gibbs, began to cry. According to court records, she filed for divorce from Staff Sgt. Gibbs in August and asked for guardianship of their 3-year-old son.
The panel of three officers and two enlisted soldiers started deliberating in a military courtroom near Tacoma shortly before 10 a.m. (1 p.m. ET) and returned its verdict around 3 p.m. (6 p.m. ET).
Phillip Stackhouse, Gibbs' defense attorney, had argued other soldiers were framing his client. Three soldiers pleaded guilty to the killings and agreed to testify against Gibbs as part of plea deals.
"What if there is no hard evidence other than what you have heard from that witness stand?" Stackhouse said Wednesday. Some witnesses also admitted to smoking hashish they obtained from Afghan translators. Their testimony, Stackhouse said, "came under a cloud of hash."
Stackhouse argued Gibbs wasn't where other witnesses said he was during the engagements. And, according to Stackhouse, in February 2010 Gibbs couldn't have smuggled an AK-47 in his backpack into a village where prosecutors said he then planted the assault rifle on the body of an Afghan man he had killed. Grasping an AK-47, Stackhouse showed the rifle would not fully fit into a soldier's backpack.
Prosecutors countered that Gibbs had used a model of the rifle that has a shorter muzzle and could be concealed