As the trial closed for Sgt. Robert Bales, he apologized for committing mass murder in Afghanistan last year and asked the jurors for leniency while they decide on his sentence.
The 39-year-old said on Friday that his brutal attack was "an act of cowardice" and performed "behind a mask of fear...and bravado" according to ABC News.
Bales went on a solo rampage on March 11, 2012 in two Afghan villages that killed 16 people and left several others injured.
"I'm truly, truly sorry to those people whose families got taken away," he said.
The jury will begin deliberating on Bales' life sentence and decide whether or not he should be granted the opportunity of parole.
When the judge, Col. Jeffrey Nance, asked Bales why he carried out such gruesome acts, Bales said "I've asked that question a million times, and there is not a good reason in the world for the horrible things I did."
While the team of prosecutors depicted Bales as an irritated solider "jacked up" on steroids, his defense lawyers tried to illustrate him as a family man who suffered from post-traumatic stress disorder. Thursday, former NFL player Marc Edwards and brother William Bales testified on his behalf.
Edwards played high school football with Bales in Norwood, Ohio and said in court on Thursday that Bales was an "unbelievable leader" on the their high school team. Bales' brother emphasized how important his family was to him.
"There's no better father that I've seen," William Bales, 55, said. "If you brought the kids in here today, they'd run right to him."
Bales pleaded guilty to the massacre in June which avoided the death penalty as a possible sentence. He was charged with murder, attempted murder, aggravated assault, and illicit use of drugs and alcohol.
Earlier this week, prosecutors called Haji Mohammad Wazir -- a villager who lost 11 family members -- to the stand.
"If someone loses one child, you can imagine how devastated their life would be," Wazir said. "If anybody speaks to me about the incident ... I feel the same, like it's happening right now."
