Was There a Second Gunman?

As reports of the 10 a.m. shooting began to surface, some stories indicated that police sought a second person of interest. The man, believed to be in his 50s, turned out to be a cab driver who had merely brought Loughner to the scene and then, he said, stuck around to get change for his passenger. But could one young man with a semi-automatic have wounded 14 people before he was tackled? Witnesses say definitely, but without security-camera footage, we may never know.