Almost immediately after the shooting of Gabrielle Giffords and several others by Jared Lee Loughner, Pima County, Arizona Sheriff Clarence Dupnik began politicizing the tragedy [1]. Part of that politicization was justified, part was not. Specifically, considering the role that an overly hostile political environment might have played in the tragedy and urging calm is acceptable, but naming specific persons (Sarah Palin and Rush Limbaugh) as possible contributing factors is not.

In any case, supporters and enablers of Palin, Limbaugh, and the tea parties movement responded by going on a witch hunt against Dupnik, using his initial claim that Loughner had made death threats [2] to claim that Dupnik knew about Loughner's issues and had done nothing. In some cases, they claimed that he had done nothing because Loughner's mother worked for Pima County. [3]

However, the police reports on Loughner's past contacts with the Pima sheriff's office (summary here; in full here) and Pima Community College (read them here; PDF cached) have been released, and neither indicate any death threats. Loughner's negative past contacts with the Sheriffs are on two minor matters; the contacts with the College are more severe however none of them would seem to offer any reasonable person a clue to what was to come.

So, while Dupnik needlessly politicized this, the teaparty enablers' attempts to smear him as incompetent or corrupt strongly appears to be false. Unless he and his office were mindreaders, there's little they could have done to stop the tragedy.

UPDATE: From this:

Jared Loughner's increasingly menacing behavior, what may look like a psychotic spiral in hindsight, likely would not have been enough to have him forced into psychiatric care, much less arrested... mental-health and legal experts say it's likely that no one could have seen a tragedy coming before Saturday... Even with Arizona's broader laws on involuntary psychiatric commitment, it's still a high bar...

ADDED: See also
* FAQ: Is Jared Lee Loughner linked to Tea Party, conservatives, or libertarians? (Gabrielle Giffords shooting)
* Jared Loughner: anti-Bush, pro-small government? Intellectually dishonest Tea Party defenders
* Loughner's "Genocide school" video
* Friend's claim that Loughner wasn't political is two years out of date
* Jared Loughner's AboveTopSecret postings show no clear political slant
* Arizona state Fusion Center uses Giffords shooting to smear American Renaissance)
* Glenn Reynolds denies Tea Party's history of intimidation
* first post on Gabrielle Giffords shooting

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[1] From this, search for more:

Dupnik called Arizona a "mecca for prejudice and bigotry," assigning a measure of blame for the rampage that killed six and wounded 14 others to overheated political "vitriol."

[2] From a 1/9/11 Reuters report (link):

Dupnik said there had been earlier contact between Loughner and law enforcement after he had made death threats, although they had not been against Giffords. He said the authorities believe he may not have been working alone.

[3] The epicenter of tea party claims was the 1/9/11 post "Jared Loughner is a product of Sheriff Dupnik’s office" (thechollajumps.wordpress.com/2011/01/09/
jared-loughner-is-a-product-of-sheriff-dupniks-office):

The sheriff has been editorializing and politicizing the event since he took the podium to report on the incident. His blaming of radio personalities and bloggers is a pre-emptive strike because Mr. Dupnik knows this tragedy lays at his feet and his office. Six people died on his watch and he could have prevented it... Jared Loughner has been making death threats by phone to many people in Pima County including staff of Pima Community College, radio personalities and local bloggers. When Pima County Sheriff’s Office was informed, his deputies assured the victims that he was being well managed by the mental health system. It was also suggested that further pressing of charges would be unnecessary and probably cause more problems than it solved as Jared Loughner has a family member that works for Pima County. Amy Loughner is a Natural Resource specialist for the Pima County Parks and Recreation.

Either that never happened, or the records linked above are incomplete. More than likely, it never happened. "The Cholla Jumps" has a follow-up post (thechollajumps.wordpress.com/2011/01/11/
loughner-history-with-law-enforcementmental-health-system-is-becoming-muddled):

I had to source the puzzle pieces and vet the information with people who assured me they had first hand information regarding Jared Loughner. I wanted documentation. Unfortunately the mere possesion of the documentation would be a violation of HIPPA laws and the track back would be detrimental to the livelyhoods and lives of the people involved... Anyone in Law Enforcement or Mental Health in Pima County that ever had contact with Mr. Loughner is now in bunker mode. Everyone is afraid of lawsuits down the road. They are evaluating their behavior and checking to make sure they followed all rules governing the care of Jared Loughner... Lawfully some of the people that had knowledge of Mr Loughner could never come forward without subpoena by a lawful authority. Others are just too afraid.

Based on that, it's almost certain that their initial report was just made up.

None of that kept AllahPundit from retransmitting their tale ("Did Clarence Dupnik miss the red flags on Loughner?", hotair.com/archives/2011/01/10/
did-dupnik-miss-the-red-flags-on-loughner), even if he CYAs:

we’re getting lots of e-mails about this post, but I’m unfamiliar with the site and can’t vouch for its credibility. Under those circumstances I’d normally pass on it, but since America’s new standard of journalism requires no supporting evidence whatsoever before tossing an assertion into the news stream, here you go. Maybe it’s true, maybe it isn’t. The important thing is, does it serve your political agenda?

Moe Lane was even less cautious (moelane.com/2011/01/10/
did-dupnik-dismiss-loughner-threat):

it is not a matter of controversy whether or not Loughner made death threats, or at least it should not be. As was reported by both local sources (via here) and Reuters, Sheriff Dupnik himself revealed that Loughner had made death threats against at least one person who was not Congresswoman Giffords. This happened. What the The Cholla Jumps site is alleging – and which has not yet been confirmed- is the following [claim as above]... The question is, is this true? We don’t know – yet – but it’s certainly plausible. Again, we know that there were death threats made, because Dupnik himself admitted that they had happened (that’s the NPR link). And we also know that Loughner was sufficiently unstable to have been thrown out of college as being, frankly, a menace to the local community. And when I say ‘thrown out’ I want it to be understood that the police were involved, because they were. But it could be that this is not actually a true report: a violent paranoid schizophrenic with a history of erratic behavior might have managed to restrain himself to making death threats to one specific person outside of the jurisdiction of the Pima County Sheriff’s Office – thus making him not specifically the problem of one Clarence Dupnik...

Needless to say, that was linked by Glenn Reynolds (instapundit.com/112919 ).

Note that AllahPundit later admitted "There were no missed red flags as far as I can tell" (hotair.com/archives/2011/01/12/
finally-dupnik-releases-police-reports-on-loughner-family).