PHOENIX - Jared Lee Loughner, head shaved, a cut on his right temple and his hands cuffed, stared vacantly at a packed courtroom on Monday and sat down. His attorney, who defended Unabomber Ted Kaczynski and Oklahoma City bomber Timothy McVeigh, whispered to him.

It was the nation's first look at the 22-year-old loner accused of trying to assassinate Rep. Gabrielle Giffords.

The three-term Democrat lay about 100 miles away in the intensive care unit of University Medical Center, gravely wounded after being shot through the head but able to give a thumbs-up sign that doctors found as a reason to hope.

Loughner seemed impassive and at one point stood at a lectern in his beige prison jumpsuit. A U.S. marshal stood guard nearby.

The judge asked if he understood that he could get life in prison - or the death penalty - for killing federal Judge John Roll, one of six who died in the shooting rampage at Giffords' outdoor meeting with constituents on Saturday at a Safeway on Tucson's northwest side.

"Yes," he said. His newly appointed lawyer, Judy Clarke, stood beside him as the judge ordered Loughner held without bail. Loughner is charged with one count of attempted assassination of a member of Congress, two counts of killing an employee of the federal government and two counts of attempting to kill a federal employee. Those are federal charges.

Throngs of reporters and television news crews lined up outside the federal courthouse, where the hearing was moved from Tucson. The entire federal bench there recused itself because Roll was the chief judge.

The Pima County Sheriff's Department on Monday released a photograph of Loughner taken at headquarters the day of the shooting. It shows Loughner staring straight into the camera, a smug look on his face.

State prosecutors, meanwhile, are researching whether they have to wait until after the federal case is resolved, or if they can proceed with local charges at the same time, an official said.

Hours earlier, the nation observed a moment of silence for the victims, from the South Lawn of the White House and the steps of the U.S. Capitol to beyond Arizona and the planet itself. At the International Space Station, Giffords' brother-in-law, Scott Kelly, the commanding officer, spoke over the radio as flight controllers in Houston fell silent.

"As I look out the window, I see a very beautiful planet that seems very inviting and peaceful," he said. "Unfortunately, it is not.

"These days, we are constantly reminded of the unspeakable acts of violence and damage we can inflict upon one another, not just with our actions, but also with our irresponsible words," he said.

"We're better than this. We must do better."

On a frigid morning outside the White House, President Obama and first lady Michelle Obama stood side by side, each with their hands clasped, heads bowed and eyes closed. On the steps of the U.S. Capitol, congressional aides and other employees did the same.

At the Supreme Court, the justices paused for a moment of silence between the two cases they were hearing Monday morning.

The president called for the country to come together in prayer or reflection for those killed and those fighting to recover.

"In the coming days, we're going to have a lot of time to reflect," he said. "Right now the main thing we're doing is to offer our thoughts and prayers to those who've been impacted, making sure we're joining together and pulling together as a country."

Scrapping her planned State of the State speech, Gov. Jan Brewer devoted her entire talk to the first day of the legislative session Monday to the tragedy in Tucson.

"This past weekend's events have caused me - caused all of us - to reflect on many things, including how we respond to those terrible events," Brewer said, before asking for a moment of silence.

"Saturday's events were not just an attack on those individuals we loved and lost, but an assault on our constitutional republic, on our democracy, on all that we treasure and hold dear as citizens and public servants," she said.

The speech was delivered in the state House of Representatives under unusually tight security, with all attendees screened for metal objects and Capitol police searching bags and purses. Department of Public Safety officers were stationed on the building roofs.

Associated Press writers Marcia Dunn in Cape Canaveral, Fla.; Paul Davenport in Phoenix; Terry Tang and Alicia Chang in Tucson; and Howard Fischer of Capitol Media Services contributed to this report.