Hello from CNN, I'm Joe Beck, with the five things you need to know for Monday, July 15th.

Nearly two days after the attempted assassination of former President Donald Trump,

investigators and officials are trying to piece together

how and why it happened.

The FBI identified the would-be assassin

as 20-year-old Thomas Matthew Crooks from Bethel Park, Pennsylvania,

but have yet to find a motive for the shooting.

A visual say Crooks acted alone and are actively investigating his background,

including working to get access to his phone.

He used an AR-style 556 rifle purchased legally by his father

and had what FBI officials say

were rudimentary explosive devices in his car.

And further questions remain about the security arrangements for the rally

and how the shooter was able to get a line of sight on Trump,

as CNN's Whitney Wild explains.

This building where the shooter had climbed up onto and shot the former president from

was outside the security perimeter.

This building was about 150 yards from where the

former president was speaking at the podium and multiple law enforcement

sources that I have spoken with have expressed a real concern, real shock that a building that close was not included in the, what they call the hard

perimeter. The Secret Service is facing calls for a congressional investigation over its handling of security for the

rally, while President Joe Biden has ordered

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