Secret Service’s Tech Flaws Helped Gunman Evade Detection at Trump Rally

After a week of oversights and failures, the officers protecting former President Donald J. Trump at a campaign rally in Butler, Pa., still had one last chance to get it right. The chance lasted about 30 seconds.

It began when a local police officer peered over the roof of the AGR International warehouse near the rally grounds and found the suspicious man he and other officers were hunting. Ninety minutes of confusion about Thomas Crooks’s intentions and whereabouts had ended in an instant.

“Long gun!” the officer broadcast over the local law enforcement radio system, according to congressional testimony from ‌the Secret Service this week.

It was urgent news that should have instantly traveled to a command center shared by the local police and the Secret Service, and then to agents close enough to throw their bodies in front of Mr. Trump. They still had time to disrupt an assassination attempt.

But the radio message never got to the Secret Service, and 30 seconds later Mr. Crooks unleashed his first shots.

That dropped communication was one of several instances where technologies that might have protected Mr. Trump from getting shot on July 13 did not — either because they malfunctioned, were improperly deployed or the Secret Service decided not to use them in the first place.