From the New York Times:
Representative Gabrielle Giffords, an Arizona Democrat, and 18 others were shot Saturday morning when a gunman opened fire outside a supermarket where Ms. Giffords was meeting with constituents.
Six of the victims died, among them John M. Roll, the chief judge for the United States District Court for Arizona, and a 9-year-old girl, the Pima County sheriff, Clarence W. Dupnik, said.
A 22-year-old suspect was in custody, law enforcement officials said. But at a Saturday evening news conference, investigators said they were looking for an accomplice, believed to be in his 50s, who may have assisted in the attack.
What a terrible, terrible tragedy.
Let us pray for the family and friends of those who were injured and those who died.
Let us pray for the violence in our country to stop.
Let us pray for the person(s) who did the shooting.
Lord, have mercy.
Christ, have mercy.
Lord, have mercy.
UPDATE: From Penelopepiscopal:
These are the names of the dead in Arizona: Christina Taylor Greene (age 9); Dory Stoddard; Dorothy Morris; Phyllis Scheck; Gabe Zimmerman; and Chief Judge John Roll of the U.S. District Court for Arizona.
Representative Gabrielle Giffords remains unconscious after surgery, in critical condition. Four others are also in critical condition and five others are in serious condidion.