At least 86 seconds, almost a minute and a half. That's how much time passed from the moment people shouted warnings about a man on a roof to when pops were heard.

We now have a better sense of the timeline from Saturday's Trump rally in Butler, Pennsylvania.

And a quick heads up that we'll be talking through and listening to some of the

videos of how that evening unfolded. If you want to really see something that said

take a look what happened. The videos raised a lot of questions for the secret service, like what happened that allowed a 20-year-old to climb a roof and attempt to

assassinate former President Donald Trump. And why couldn't anyone stop him?

After Trump ducked down onto the stage, secret service agents could be heard

asking the question that a lot of people had in the aftermath. What are we doing?

What was the secret service doing? What was the Secret Service doing?

You know, when I first heard this news, it was from my editor calling me to tell me that he needed my help. As soon as he told me I went to the videos,

I went to all of the material like it's Gower and what I was stunned by was that it appeared to be an open line of sight

between where the shooter was on a roof directly to the stage where Donald Trump was standing. This issue of line of

sight is something that secret service agents have been sleepless about since 1963.

That's Carol Lening.

She's an investigative reporter at the post.

She's reported extensively on the Secret Service.

She even wrote a book about the agency. It focused in part on how much security

has changed since the assassination of John F. Kennedy.

Every single agent that works on a security plan for an event.

Their first step is,

where are the lines of sight to possibly harm my

protectee, my president, or my vice president or my candidate and then they seek to

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