Barack Obama broke off from political campaigning to comfort families in the Colorado town where 12 people were massacred at a midnight Batman film screening.
Air Force One touched down at Buckley Air Force Base in Aurora for the US President's hastily-arranged two and a half-hour visit, which included a private meeting with families and a public comment about Friday's shooting at a busy multiplex cinema which was showing The Dark Knight Rises. Two of the victims served at the base.
Colorado governor John Hickenlooper, Aurora mayor Steve Hogan and Aurora police chief Dan Oates were among those who greeted Mr Obama at Buckley.
The President met family members at the University of Colorado Hospital in Aurora, which treated 23 of the 58 people injured in the mass shooting. Ten remain there, seven in a critical condition.
Mr Obama said that he told the families of the victims that "all of America and much of the world is thinking about them". Republican challenger Mitt Romney said Mr Obama's decision to meet the families was "the right thing".
The senseless killings - apparently the work of an unhinged former doctoral student - briefly silenced the presidential campaign over the weekend. Both Mr Obama and Mr Romney cut short their schedules late last week and closed down their television advertising in Colorado out of respect for the victims and their families.
The president planned just a brief visit to the Denver suburb, where the shots rang out. "I think the President coming in is a wonderful gesture," said mayor Mr Hogan. "He's coming in, really, to have private conversations with the families. I think that's totally appropriate." He told ABC television's This Week that it "certainly means a lot to Aurora to know that the president cares".
Aides said Mr Obama received updates on Saturday from his homeland security adviser John Brennan, on the investigation into the shooting and the attempts by authorities to gain access to the suspect's apparently booby-trapped flat nearby.
For Mr Obama, the Colorado visit was to be his second to the state in just over three weeks. Last month, he flew to Colorado Springs to share the pain of homeowners whose houses had been razed by a record outbreak of wildfires.
Mr Romney told a previously scheduled event in Bow, New Hampshire, that he joined with the president and first lady in offering condolences for those "whose lives were shattered in a few moments, a few moments of evil in Colorado".