The 22-year-old man suspected in the deadly shooting rampage Saturday in Arizona was described by the local sheriff as "unstable" and with a "kind of troubled past."
Fox News sources identified the suspected shooter as Jared Loughner.
At a press conference held Saturday evening, Pima County Sheriff Clarence Dupnik said the man suspected in the mass shooting that left six dead and more than a dozen injured has a criminal background and "there is reason to believe he has a mental issue."
"When you look at unbalanced people, how they respond to the vitriol that comes out of certain mouths about tearing down the government. The anger, the hatred, the bigotry that goes on in this country is getting to be outrageous," the sheriff said.
"And unfortunately, Arizona I think has become the capital. We have become the mecca for prejudice and bigotry."
Loughner is suspected of posting a series of YouTube videos that show a focus on literacy and currency -- as well as his distrust in the government.
"Hello, my name is Jared Lee Loughner," one of the videos says, in words appearing on the screen. "This video is my introduction to you! My favorite activity is conscience dreaming; the greatest inspiration for my political business information. Some of you don't dream - sadly."
The video, posted Dec. 15, later turns more political.
"The majority of citizens in the united states of America have never read the united states of America's constitution. You don't have to accept the federalist laws," the video's titles say. "In conclusion, reading the second United States constitution, I can't trust the current government because of the ratifications: the government is implying mind control and brainwash on the people by controlling grammar. No! I won't pay debt with a currency that's not backed by gold and silver! No! I won't trust in god!"
Arizona Rep. Gabrielle Giffords was among the people critically wounded in the shooting at a public event in Tucson, and several people were killed, including a federal judge and a 9-year-old girl.
Officials have said little publicly about the suspect in custody, but law enforcement sources who asked to remain anonymous identify him as Loughner.
Records obtained from the Pima County, Ariz. criminal database show Loughner was arrested in 2007 for possessing drug paraphernalia, a misdemeanor charge. The records suggest that Loughner paid a $20 fee and completed a court-ordered program for drug offenders.
Three months later he was cited for running a stop sign, according to court documents.
Another record shows a 2008 arrest for what’s described as a “local charge” in Marana, Ariz., 20 miles northwest of Tucson. The non-criminal charge was dismissed.
Loughner's page on YouTube lists Tucson as his hometown. He also said he attended Northwest Aztec College and Pima County Community College. And in one of the videos, he says he is a military recruit.
But an Army official told Fox News Loughner attempted to enlist in the Army in December 2008 but was denied.
The Army provided this statement:
"The Army has confirmed that the suspect was never in the Army. He attempted to enlist in the Army but was rejected for service. In accordance with the Privacy Act, we will not discuss why he was rejected."
In other videos, Loughner calls the people of District 8, his Ariz. district, illiterate.
In a bizarre equation that Loughner appears to mean as example of deductive reasoning, he concludes that "the police are unconstitutional."
In yet another rant verging on the paranoid, he says:
“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.”
He lists reading under interests, as well as "conscience dreams," and among his favorite books are "Mein Kampf," the "Communist Manifesto," "Animal Farm" and "Brave New World."
In a comment posted on MySpace three months ago in connection with a video about Pima Community College, Loughner wrote: "Hello, I know you’re illiterate! This is the greatest protest for exposure into a wrongful act. The school is breaking the constitution. If you watch the video then you’ll understand. The teachers are taking advantage of you in the first and Fifth Amendment. The United States Constitution, which is the law, can be broken at this school. Thank you and goodnight! Jared"
His last writing on his MySpace page was just hours before the shooting.
"Goodbye friends," he wrote. "Please don't be mad at me."