TUCSON, Ariz. -- Former classmates of Jared Loughner, accused of a fatal shooting rampage outside a Tucson grocery store, described him as opinionated and not concerned about what people thought of him.
Loughner, 22, was taken into custody minutes after Congresswoman Gabrielle Giffords and 18 others were gunned down Saturday, shortly after the Democratic lawmaker began a "Congress on Your Corner" event.
Jeff Shope, who went to high school with Loughner, said, "I want to know why he did it. Obviously, there's looking into that. (I have) no clue."
The New York Times reported that a video that Loughner made caused officials at Pima Community College to suspend him and tell his parents he could not return until he had a mental health evaluation. Loughner attended Pima from the summer of 2005 until October 2009 when he withdrew after the suspension.
A Tucson Army recruiter, 1st Sgt. Brian Homme, told that Lughner tried to enlist in the Army in 2008 and took a physical. Homme said he was rejected as unqualified. He declined to provide further information, saying the Army does not make its reasons public.
A former friend of Loughner, Caitlin Parker, told ABC News that the suspect had once met Giffords.
"As I knew him more and more after high school, he got a little more odd," said Parker. "I mean, he was obsessed with the 2012 prophecy. He met Gabrielle Giffords once in '07 and told me he asked her some question that made absolutely no sense to me, but he said, `I can't believe she doesn't understand it. Politicians just don't get it.'"
Lynda Sorenson said she once took a math class with Loughner said said he "disrupted class frequently with nonsensical outbursts."
As of Saturday evening, Pima County Sheriff Clarence Dupnik said the gunman may not have acted alone.
"Overnight, authorities released a surveillance camera photo of a man taken near the shooting scene. They said they wanted to talk to the man -- a white male with dark hair, dressed in blue jeans and a dark blue jacket.
The photo showed a man walking into a store with his hands in his pockets. Authorities said he is 40 to 50 years old.
at least five people were killed and Giffords was shot in the head in the episode, which unfolded as the Democratic congresswoman was greeting constituents in her district in Tucson, Arizona.
Police say the shooter is in custody. He has been identified by officials familiar with the investigation as Jared Loughner, 22.
Officials say Loughner told authorities at the scene he had acted alone, although it is not certain that is the case. "