Editor's note: The following is an updated profile of Pfc. Bradley Manning published August 5, 2010, before he'd answered to allegations of leaking classified information to WikiLeaks.
(CNN) -- Bradley Manning is naturally adept at computers, smart and opinionated, even brash, according to those who say they know him.
It's been almost three years since Bradley Manning was tossed into solitary confinement at Marine Corps Base Quantico in Virginia, facing allegations that he facilitated the largest-ever intelligence leak in U.S. history.
Tuesday, a court-martial judge found the 25-year-old Army private guilty of most of the charges against him.
However, he was found not guilty on the most serious charge, that of aiding the enemy, which falls under the Espionage Act. He could have been sentenced to life in prison on that charge.
The judge accepted some of the guilty pleas he had entered in February to 10 lesser charges related to the alleged dissemination of about 750,000 pages of classified documents and videos to WikiLeaks. The leaks dealt with everything from U.S. military strategy in Iraq to State Department cables outlining foreign relationships and included a secret military video from the Iraq war.
The charges to which he's pleaded guilty carry a potential sentence of 20 years behind bars. WikiLeaks, which facilitates the anonymous leaking of secret information, has never confirmed Manning was the source of its information.
Since his arrest, Manning has been moved to a military prison cell at Maryland's Fort Meade.
Friends and acquaintances describe Manning as a person who, from a young age, couldn't help but get involved when he perceived an injustice. It was a tendency that sometimes sparked confrontation with authority figures and those who disagreed with him, they say.
According to friends and his own writings on the internet, Manning is openly gay.
Judging by his Facebook page, the young soldier's politics appear to be left-leaning, and he's an ardent supporter of groups working to achieve full civil rights for gays. Manning listed on his page groups including Human Rights Campaign and the National Center for Transgender Equality, and causes such as "Repeal the Ban -- End Don't Ask, Don't Tell" and "No on Prop 8," a California ballot measure that eliminated the right to marry for same-sex couples.
It's unclear if those politics may have had any role in what authorities accuse him of doing.
'A sincere boy'
"ive been so isolated so long ... i just wanted to be nice, and live a normal life ... but events kept forcing me to figure out ways to survive ... smart enough to know whats going on, but helpless to do anything ... no-one took any notice of me"
That is an instant message Manning allegedly sent on May 22, 2010, to Adrian Lamo, a 29-year-old former hacker from California who pleaded guilty in 2004 to breaking into The New York Times secure computer network. The chats between Lamo, in California, and Manning, in Iraq, stretched over a few days, and Manning initiated them, Lamo said.
Lamo went to the FBI after Manning allegedly confessed to leaking classified documents. The ex-hacker told CNN he doesn't know why Manning would trust him, a stranger he'd never met.
Lamo confirmed he told Manning the soldier's online conversations could be protected under the California shield law because it could be seen as a conversation with a journalist. Lamo said at the time that he considers himself a journalist and that he made the offer in good faith.
Manning seemed "naive," Lamo said, "easily led," but a "genuine, sincere boy."
"The only thing I know about Bradley Manning, based on his chats, is that he believed he was doing the right thing by releasing that information -- the right thing being, in his mind, to demonstrate that the U.S. had done bad things in war," Lamo said.
Heated arguments, sense of 'justice'
Bradley Manning grew up in Crescent, Oklahoma, a 1.1-square-mile town north of Oklahoma City. His father, Brian, is reportedly a military veteran.
Manning's mother has kept a low profile, but people in Crescent remember her well.
"When you saw Bradley, his mother was there. She was involved," said then-Crescent school administrator Rick McCombs in 2010.
"He was very outspoken in class about government issues and religious beliefs and stuff like that," recalled junior high classmate Chera Moore. "Sometimes he would get in heated arguments in class if he didn't agree with certain things."
Manning didn't care for sports; he joined band. He was quick at computers and got straight As until the end of junior high when his grades dropped to Bs and Cs, McCombs said.
It was 2001, reportedly around the time his parents divorced, that Manning's mother took her 13-year-old out of school, and they moved across the Atlantic to Wales.
Manning attended Tasker Milward in Pembrokeshire County, in central Wales. The school required students to wear forest-green V-neck monogrammed sweatshirts.
At 15, Manning stood out as a novelty for being American, said classmate Tom Dyer, who hung out at Manning's home at least three times. The mother was quiet, he recalled, but Manning was more passionate.
"He was quite energetic, always full of ideas and had a high moral compass. He would always speak up if he thought that something was wrong without actually thinking of the consequences," said Dyer, who still lives in Pembrokeshire. "Bradley had a great sense of justice."
Though Dyer is Facebook friends with Manning, he said they have not spoken in two years. Dyer said he was taken aback to hear Manning had joined the U.S. Army.
"He did not have a build for that, you know what I mean?" Dyer told CNN.
Former Tasker student James Kirkpatrick agreed with Dyer, saying that the Army seemed an odd choice for Manning. Kirkpatrick kept in touch with Manning, saying in 2010 he had talked to the soldier as recently as six months earlier.
"He didn't mention anything about what was happening, but at the same time he did seem a bit secretive," the ex-classmate said. "He was being a bit paranoid about what we did speak about on the 'net."
Out and down
"my family is non-supportive . . . im losing my job . . . losing my career options . . . i dont have much more except for this laptop, some books, and a hell of a story." -- Washington Post, instant message allegedly from Manning to Lamo.
Manning dropped out of Tasker and moved back to America in 2005. He told Lamo that he was homeless and had drifted around the country until he landed in Potomac, Maryland, where his aunt took him in.
A former soldier said he met Manning during this time in a Washington nightclub, and they had a physical relationship. The man, whose identity CNN isn't releasing, said the young soldier seemed "shy, very quiet, introverted."
"Brad was very different from anybody else at the club. He didn't really look like anybody else at the club," the man told CNN. "I mean, he was very slight, physically. He just appeared really out of place and really lonely."
Their relationship evolved into a friendship, and the two frequently talked about each other's dreams and ambitions, their fears, insecurities and frustrations. Manning told him he was viciously made fun of in the military for being gay. Basic training was "difficult ... because of his sexuality," the man said.
"He had given me indication that the same type of thing that he had dealt with before, as far as verbal abuse, you know, emotional abuse, derogatory comments pertaining to his sexuality," the man told CNN.
Manning didn't recognize the treatment as discrimination, the man said.
"When it came to these things, I felt like he was frankly a little bit naive," the man said. "I didn't think he realized what was happening to him. ... I think at first he felt just terrible that people would say something like that to him, and embarrassed, obviously."
Manning was "probably more angry at the military and the whole way everything was run and that was probably why I felt like he was disgruntled towards the end," he added.
Apart from discrimination, the man said Manning had a rough go with his family. He had to leave his father's home, for unknown reasons, and became homeless. Manning drove across the country, living out of a beat-up red truck, working odd jobs, the man said.
In the Army now
After a short stint at Maryland's Montgomery College, and a pizza-delivery job for minimum wage, Manning enlisted in October 2007. He went to Fort Leonard Wood, Missouri, for basic training the next year.
Things did not go smoothly.
At an Arizona base in 2008 during advance training that would turn Manning into an intelligence analyst, the young soldier was reprimanded, the military said, without elaborating on details. Wired magazine reported that Manning had been caught uploading videos on YouTube in which he talked about classified buildings.
Manning graduated advanced training and was sent to Iraq. He was given top-secret security clearance.
Manning was arrested in June 2010 in connection with the release of classified U.S. military combat video, which showed the shooting deaths of Iraqi civilians and two journalists in 2007 by a helicopter gunship.
He initially invoked the Fifth Amendment and refused to answer questions, a Pentagon official said, but in February, when he entered his guilty plea to certain charges, he spent more than an hour in court reading a statement detailing why and how he sent classified material to WikiLeaks.
A few months before his arrest, Manning was demoted a stripe to private for getting into a fight with another soldier, a military official told CNN. The circumstances were unclear.
The military first held Manning in a Kuwait jail for allegedly leaking the helicopter video, before moving him to Quantico.
When WikiLeaks published its Afghanistan war documents in July 2010 and Manning became the prime suspect in those leaks, people across the world weighed in. Some called him a traitor. Others banded together to support him.
"If he feels like no one out there cares, he's wrong," Jeff Paterson, an ex-Marine who started bradleymanning.org, said in 2010.
The online support network raised thousands for his defense, and WikiLeaks has continued to support Manning.
CNN's Larry Shaughnessy in Oklahoma and Atika Shubert and Andrew Carey in Wales contributed to this report, as well as CNN's Eliott C. McLaughlin, Chelsea J. Carter, Chris Lawrence, Barbara Starr, Laurie Ure, Amy Roberts and Taryn Fixel.