Doctors at press conference in Tucson say Rep. Giffords remains in critical condition but is able to follow simple commands as she’s come out of heavy sedation. They remain “cautiously optimistic” about her chances of survival.

Giffords’ medical situation remains “precarious,” doctors say. It is a life-threatening injury. That being said, doctors emphasized that her injuries are on the less severe end of the spectrum of penetrating brain injuries.

In cases like this, the small victories are often blown out of proportion. It sounds like Giffords has a long and difficult recovery ahead lasting months if not years. But that she starts down that road to recovery with several factors in her favor: where the bullet penetrated, what it hit and didn’t hit, a high level of brain function after surgery, and quick medical intervention.

Sen. Jon Kyl (R-AZ) not happy with local sheriff over comments about Arizona being a mecca for bigotry: “I didn’t really think that that had any part in a law enforcement briefing.”

FBI Director Robert Mueller is holding a press conference right now in Arizona. Formal charges will “quite probably” be filed against Jared Loughner this afternoon, Mueller said, for the killing of Judge Roll and the assault on Rep. Giffords and her staffers.

“It appears that the target was the congresswoman,” Mueller said.

Mueller would not preclude the bringing of additional charges under the domestic terrorism statutes as the investigation unfolds.

The local sheriff in Tucson says their thinking has changed and that they are now less sure than the person of interest they are seeking had any connection to suspected shooter Jared Loughner or any role in the shooting. But they still want to talk to the guy.

A lot of attention has been paid today to a Fox News report about what was originally described as a leaked “DHS memo” that tied Jared Loughner to an anti-immigration, racist group called American Renaissance.

But Fox has walked back its initial description of the memo as coming from the Department of Homeland Security. Now it uses a labored description: “a law enforcement memo based on information provided by DHS.”

That’s not the same thing as a DHS memo, and it suggests somewhat less certainty about whether Loughner’s reference to the group in his internet ramblings is getting special attention from law enforcement.

Statement just out from President Obama:

“Tomorrow at 11:00 a.m. eastern standard time, I call on Americans to observe a moment of silence to honor the innocent victims of the senseless tragedy in Tucson, Arizona, including those still fighting for their lives. It will be a time for us to come together as a nation in prayer or reflection, keeping the victims and their families closely at heart.”

Obama will observe the moment of silence with staff on the South Lawn, according to the White House.

The President has ordered flags flown at half staff and has postponed a trip to New York scheduled for Tuesday.

Still no word on whether the President will travel to Tucson.

The sheriff in Tucson just confirmed during an interview with Fox News that the second person sought in connection with the Giffords shooting “turned out to be a cab driver who went into the Safeway with [Jared Loughner] because he needed change to pay for the cab.” More soon …

Feds charge Jared Loughner with one count of attempting to kill a member of Congress, two counts of first degree murder and two counts of attempted murder for the Tucson shooting.

We’ve posted the charges.

House to hold joint meeting of Republican and Democratic caucuses on Wednesday in wake of Giffords shooting. That news emerged after a conference call this afternoon to update Members and their staffs and families in which Giffords’ chief of staff Pia Carusone spoke.

Judy Clarke, who has represented “Unabomber” Ted Kaczynski and Zacarias Moussaoui, will be representing accused mass murderer Jared Lee Loughner.