奥巴马演讲:力求平息枪击案风暴

At the crowded University of Arizona, US president Barack Obama consoled the nation over Saturday's shooting spree in Tucson. With a half-hour speech, Obama paid tribute to the six people killed and 14 wounded.

The tribute began with solemn music.

Obama promised the families of the victims he was praying for them now and would stand by them in the future. He also vowed to punish the person responsible.

Following a hospital bedside visit with Congresswoman Gabrielle Giffords, the target of the assassination, Obama shared some good news.

As the memorial service was underway, investigators were piecing together the timeline of suspect Jared Loughner's frenzied morning before the assassination. He seemed to have a serious confrontation with his father in a mega-store before the shooting spree.

Federal prosecutors have charged Loughner, 22, with five counts so far. He faces a possible death sentence.