Criticism of the Secret Service is growing after the assassination attempt on Republican presidential candidate Donald Trump during a campaign meeting in the state of Pennsylvania.
It wasn't until after the shots were fired that the 20-year-old shooter was discovered on a roof of a building just outside the cordoned-off area where Donald Trump was holding his meeting.
The roof from which the suspected perpetrator shot had been identified as "vulnerable" days before the campaign meeting, reports TV channel NBC News, citing sources within the Secret Service.
Someone should have been on the roof or secured the building so that no one could climb up onto the roof, says a former Secret Service employee to the TV channel.
An eyewitness tells BBC that he saw an armed man climb up onto the roof – and that he tried to alert the police to the shooter.
According to the FBI, it took 22 seconds from the shots being fired until the armed security forces reached the podium where Trump was standing.
Understanding how the armed man got up onto the roof is a central question in the investigation.
The Secret Service worked together with local law enforcement agencies to maintain security at the site. They had, among other things, snipers in place, ready to identify threats, according to NBC News.
Just because it's (the roof) outside the area doesn't mean it's not vulnerable, says a source to NBC News.
Secret Service Chief Kimberly Cheatle writes in a statement on Monday that she has full confidence in the security plan for the Republican Convention, which starts in the afternoon Swedish time, reports CNN.
Cheatle is to be heard at an inquiry into the shooting on July 22.
