It is sad when people are killed in such a violent and senseless attack. Now is the time for all of us to RADIATE love - even though a gunman intended to assassinate a U.S. representative when he opened fire outside a Tucson, Arizona, supermarket Saturday, killing six and wounding 12 including the congresswoman, the local sheriff said hours after the shooting.U.S. Rep. Gabrielle Giffords was in critical condition late Saturday after surgery for a single gunshot wound to the head. The dead included a federal judge and a 9-year-old girl, authorities said.One suspect was in custody immediately after the shooting, and investigators were "actively in pursuit" of a second man whom they believed may be involved in the attempted assassination, Pima County Sheriff Clarence Dupnik said Saturday night.Two people tackled the suspected shooter, stopping a spray of bullets from what federal and state law enforcement sources described as a 9mm Glock outfitted with a 30-round magazine.Dupnik said the suspect in custody is 22, but declined to name him. An Arizona law enforcement source and a federal law enforcement source, meanwhile, identified the suspect as Jared Lee Loughner.A gunman opened fire as a congresswoman was meeting with constituents outside a grocery store, killing a federal judge and five others and leaving the lawmaker fighting for her life in a rampage that had Americans questioning whether divisive politics had pushed the suspect over the edge. Pima County Sheriff Clarence Dupnik said Democratic Rep. Gabrielle Giffords was the target of a gunman whom he described as mentally unstable and possibly acting with an accomplice. He said Giffords was among at least 13 people wounded in the melee. Six people were killed, including Arizonaand#39;s chief federal judge, a 9-year-old girl and an aide for the Democratic lawmaker. He said the rampage ended only after two people tackled the assailant.