Even the sheriff knows Loughner is crazy, per this long New York Times piece on the killer:
“There’s no doubt in my mind that the whole trial will be about did he know right from wrong,” the sheriff said. “We’ll have 15 psychiatrists saying yes. We’ll have 15 psychiatrists saying no. What do I say? I think he’s mentally disturbed.”
Disturbed enough to be found guilty but insane?
“I majored in psychology at the university,” Sheriff Dupnik answered. “Based on what I’ve seen, he is psychotic, he has serious problems with reality, and I think he’s delusional. Does he meet the legal test of guilty but insane? I don’t know.”
There’s also this detail on Loughner:
He became intrigued by antigovernment conspiracy theories, including that the Sept. 11 attacks were perpetrated by the government and that the country’s central banking system was enslaving its citizens. His anger would well up at the sight of President George W. Bush, or in discussing what he considered to be the nefarious designs of government.