Is Tucson Sheriff Clarence Dupnik culpable in the Giffords shooting? By failing to do his job?

There are reports that he knew of many death threats by Loughner, but failed to take action:

Jared Loughner is a product of Sheriff Dupnik’s office

Did the Sheriff fail to act, because Loughner's mother was a county employee? Is it true that if the Sheriff had done his job, Jared Loughner would have been flagged as dangerous, and not been eligable to purchase a gun?

Where is the MSM on this story? Isn't this the sort of thing journalists are supposed to investigate? No, apparently not. Instead, they are too busy helping Democrat Demagogues to declare war on talk-radio.

As the Dems on the far Left like to say, "Never waste a crisis tragedy".