Trump rally shooter Thomas Matthew Crooks was perceived by the U.S. Secret Service as a "person of interest," not yet a "threat" after law enforcement saw him acting suspiciously and determined he had a golf range finder, according to Secret Service Spokesman Anthony Guglielmi.
Crooks was only identified as a threat when he "retrieved the weapon" and climbed onto the roof of a building just prior to the shooting on Saturday in Butler, Pennsylvania, according to Guglielmi, who added that a threat requires, "a different protocol and a different course of action than a person of interest."
Guglielmi maintains that it was only once Crooks retrieved his weapon and got onto a building's roof in the area where Trump was holding the rally that he was identified as a threat.
Soon after that, Butler Township police officers confronted Crooks on the roof and he pointed his weapon at one of them, who then dropped off the roof.
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Crooks then fired on former president Trump and was taken out by a Secret Service counter sniper.
The FBI is leading the investigation into the attack on Saturday at the Trump campaign event. The motive as to why Crooks opened fire at Trump remains unknown.
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Secret Service and FBI officials told U.S. senators during an all-members briefing on Wednesday that Crooks, 20, wrote a threatening message on the gaming platform "Steam" days before the attempted assassination.
According to the officials, Crooks allegedly wrote: "July 13 will be my premiere, watch as it unfolds."
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In the wake of the incident, Secret Service Director Kimberly Cheatle is facing pressure to resign, with House Speaker Mike Johnson, R-La., telling FOX Business on Thursday that he is ready to call on President Biden to fire her.
Fox News' Lawrence Richard and Jacqui Heinrich contributed to this report.