Details of Trump shooting security breakdown start to emerge 

Amid swirling questions over how the Secret Service allowed a gunman with an AR-style rifle to get close enough to shoot and injure former President Trump at a Saturday rally, some answers are starting to emerge. 

The security gap appears to stem from how and what the agency communicated with local law enforcement before and during the event, and the apparent decision not to place security personnel on the building the gunman climbed up before shooting.

The gunman — Thomas Matthew Crooks, 20, of Bethel Park, Pa.