He did not go through security. That building was not in the security perimeter.
You did not need to go through a metal detector to be that building.
Apparently Crooks was seen pacing by the metal detectors and someone told the cops he was being suspicious.
EDIT: John Miller says "he leaves the secure area" which definitely sounds like he went in. However I read local LEO saying he saw the metal detectors and didn't go in.
Several rallygoers reported to local officers that Crooks was acting suspiciously and pacing near the magnetometers, according to a law enforcement official who spoke on the condition of anonymity because the official was not authorized to discuss the investigation.
The suspicious person, later identified as Thomas Crooks, 20, was first flagged to local police officers by rallygoers on their way into the event. The attendees reported they saw Crooks pacing and behaving strangely near the magnetometers, four officials told NBC News.
He did not go through security. That building was not in the security perimeter.
You did not need to go through a metal detector to be that building.
Apparently Crooks was seen pacing by the metal detectors and someone told the cops he was being suspicious.
EDIT: John Miller says "he leaves the secure area" which definitely sounds like he went in. However I read local LEO saying he saw the metal detectors and didn't go in.
ABC
https://abcnews.go.com/US/wireStory/signs-trouble-trump-rally-evident-minutes-gunman-opened-111966629
NBC
Local Channel 7 https://x.com/WJHG_TV/status/1812977981989535933