 One of the biggest remaining questions surrounding the deadly shooting at the Trump political rally was how was it possible that the gunman could have been allowed to make his way to the roof of a building less than 500 feet away from the former president to take aim at him, despite eyewitnesses saying they warned police of the man's suspicious behavior before the bullets started flying. For more, we welcome retired Sergeant Betsy Brantner-Smith, spokesperson for the National Police Association.