The man linked to the shooting today of Rep. Gabrielle Giffords and others is 22-year-old Jared Lee Loughner, the Associated Press reported.

Saturday afternoon, police surrounded a house in the 7700 block of North Soledad Avenue, at the address listed by a man with the same name on a variety of online accounts and in the volunteer registry for the 2010 Tucson Festival of Books. The home is near West Magee Road and North Thornydale Road on the northwest side, about five miles from the shooting scene.

Pima County Sheriff Clarence Dupnik would not confirm Loughner is the suspected shooter. He said the person arrested for the shooting is uninjured and uncooperative.

The suspected shooter has made death threats before and been contacted by law-enforcement officers, but the threats weren't against Rep. Gabrielle Giffords, Dupnik said. The suspect is unstable, Dupnik said, but the sheriff would not say he is "insane."

A former classmate of Loughner at Pima Community College said he was "obviously very disturbed."

"He disrupted class frequently with nonsensical outbursts," said Lynda Sorenson, who took a math class with Loughner last summer at Pima Community College's Northwest campus.

Sorenson doesn't recall if he ever made any threats or uttered political statements but he was very disruptive, she said. He was asked to leave the pre-algebra class several times and eventually was barred from class, said Sorenson, a Tucson resident.

Another Pima classmate, Lydian Ali, said Loughner would frequently laugh aloud to himself during the advanced-poetry class they attended. Only about 16 people were in the class, so Loughner's behavior stood out, Ali said.

"It almost seemed like he was on his own planet, because his comments would have nothing to do with what we were talking about," Ali said.

MySpace, YouTube and Facebook accounts maintained by Loughner suggest he has spent most of his life on the northwest side: His profile says he attended Thornydale Elementary, Tortolita Middle School, Mountain View High School

The online accounts also contain bizarre discussions of a new currency and literacy, as well as threatening and despairing messages.

"WOW! I'm glad i didn't kill myself. I'll see you on National T.v.! This is foreshadow .... why doesn't anyone talk to me?.." he posted on MySpace Dec. 14.

On Dec. 13, he wrote: "I don't feel good: I'm ready to kill a police officer! I can say it."

In a posting on YouTube, Loughner wrote repeatedly about a new currency.

"I'm thinking of creating a new currency," he wrote. "Therefore, I'm thinking of a design for my new coins size, shape, color, material, and image to start a new money system."

He also wrote repeatedly about literacy. In a written message on YouTube, Loughner said: "The majority of people, who reside in District-8 are illiterate - hilarious. I don't control your English grammar structure, but you control your English grammar structure."

In a message posted on his MySpace account, titled "Goodbye friends," Loughner said: "Dear friends...please don't be mad at me. The literacy rate is below 5%. I haven't talked to one person who is literate." It was unclear when it was posted.

In a MySpace profile, Loughner said "My favorite interest was reading, and I studied grammar. Conscience dreams were a great study in college."

He lists among his favorite books "Mein Kampf" and "The Communist Manifesto". But he also includes a broad variety of other titles, including: "Animal Farm," "Brave New World," "To Kill a Mockingbird," and "One Flew Over the Cuckoo's Nest".

In another YouTube message, Loughner said: "I know who's listening: Government Officials, and the People. Nearly all the people, who don't know this accurate information of a new currency, aren't aware of mind control and brainwash methods. If I have my civil rights, then this message wouldn't have happen."

"In conclusion, my ambition - is for informing literate dreamers about a new currency; in a few days, you know I'm conscience dreaming! Thank you!"

In a YouTube video dated Dec. 15, titled "Introduction: Jared Loughner" the accused gunman describes himself as a U.S. military recruit who had applied to join the Army. The Army, however, said it rejected Lougher as a recruit in 2008.

In the video, Loughner makes a rambling mention of "MEPS in Phoenix" a reference to the Military Entrance Processing Station in the state capital that all Arizona recruits from every branch of service pass through before leaving for basic training.

"Every United States military recruit at MEPS in Phoenix is receiving one mini bible before the tests," it said. "Jared Loughner is a United States military recruit at MEPS in Phoenix. Therefore, Jared Loughner is receiving one mini bible before the tests.

"I didn't write a belief on my Army application and the recruiter wrote on the application: None."

First Sgt. Brian Homme, who oversees Army recruiting in Tucson, said Loughner applied to enlist in December 2008 and was sent to Phoenix to take a test and physical. But "he was found to be unqualified so he never joined the Army," Homme said.

He declined to say why Loughner was rejected, citing confidentiality laws.

Loughner has had at least two minor run-ins with police, according to on-line court records.

In October 2007, Loughner was cited by the Pima County Sheriff's Department for possession of drug paraphernalia, a charge that was dismissed in November 2007 when he completed a diversion program.

One year later, in October 2008, Loughner was charged with a "local charge" in Marana Municipal Court, that charge was also dismissed following the completion of a diversion program in March 2009.

Court records indicate the Marana case file is due to be purged in December 2013. It's unclear what the exact charge was.

Grant Wiens, 22, attended Mountain View High School with Loughner, although they were not in the same grade.

Wiens also took a class at Pima Community College with Loughner, where they occasionally talked, he said.

"He was a guy in high school who definitely had his opinions on stuff and didn't seem to care what people thought of him," Wiens said. "He did his own thing."

Ryan Miller, 19, was a sophomore at Mountain View when Loughner was a senior.

He said Loughner was seemed like a normal kid.

"I was in shock," he said, describing his reaction to the shooting. "I didn't know what possessed someone our age to do something like this."