"We have a mentally unstable person in the class that scares the living crap out of me. He is one of those whose picture you see on the news, after he has come into class with an automatic weapon. Everyone interviewed would say, Yeah, he was in my math class and he was really weird. I sit by the door with my purse handy. If you see it on the news one night, know that I got out fast..."
That from Lynda Sorenson in an email regarding Jared Loughner of whom she was a classmate at community college in Tucson.
Thus far, any and all accounts of Loughner point to him simply being a deranged wacko but my oh my has the press tried to paint him as being motivated by something other than just his own lunacy.
Captain Ed has a good round-up of the media hypocrisy that exists with respect to how different shootings are handled, here.
Just remember that when jumping to conclusions, Loughner was a white male. That's about all you really need to know in order to get started.