TUCSON, Ariz. -- As the investigation into Saturday's tragic shootings here continues, on Sunday afternoon authorities said they had found a second person they had been seeking and had subsequently interviewed and cleared him of any involvement in the shootings.

Pima County Sheriff Clarence Dupnik said in an interview that the man, whom he declined to identify, was a taxi driver who had driven the shooting suspect, Jared Lee Loughner, to the Safeway supermarket and dropped him off. The driver then apparently entered the supermarket...