Doctor at Trump rally says he rendered aid to badly wounded shooting victim: "There was lots of blood"

An emergency room doctor attending former President Donald Trump's campaign rally in Pennsylvania told CBS News that he tried to help render aid to an audience member who was gravely wounded when a gunman opened fire on Saturday.

The gunman, identified as 20-year-old Thomas Matthew Crooks, fired several rounds while Trump was speaking at the rally in Butler, Pennsylvania, grazing the former president's ear. One rallygoer was killed and two others were critically wounded, the FBI said. 

Dr. Jim Sweetland, who spoke to CBS News campaign reporter Jake Rosen right after the shooting, said when he heard the loud bangs, he first thought they were firecrackers before realizing they were gunshots.