Would-Be Trump Assassin’s Interest in Violence Went Back to 2019

The man who tried to kill former President Donald J. Trump in July first showed an interest in committing acts of public violence in 2019 but narrowed his focus to Mr. Trump after the announcement of his rally in Butler, Pa., according to an F.B.I. analysis of his electronics.

Investigators — who performed an exhaustive search of his devices and online accounts — do not believe that Thomas Crooks, the would-be assassin who was killed by a Secret Service sniper, was motivated by a specific political ideology. They have found no evidence that he had any co-conspirators or connections to a foreign plot, F.B.I. officials said during a call with reporters on Wednesday.

Soon after, the bureau for the first time released evidence photographs, including the shooter’s gun — a matte black Panther Arms AR-15-type semiautomatic rifle with a removable stock — the oversized black backpack found next to his body and an improvised explosive device found in the trunk of his car.

While Mr. Crooks’s motive remains opaque, his online searches reveal someone who was looking for an opportunity to pull off a spectacular attack that would garner widespread attention, by either inflicting mass casualties or killing someone famous. Thus far, that profile more closely resembles that of a mass shooter than a politically motivated assassin.

Starting as a teenager in 2019 through this year, Mr. Crooks progressed from searching “detonating cord,” “blasting cap” and “how to make a bomb from fertilizer” to seeking detailed information about the activities and whereabouts of politicians in both parties. By late 2023, his search history included queries related to Mr. Trump, President Biden and both parties’ conventions, the officials said.