Thomas Crooks opened fire at a Trump rally last year, firing eight shots, killing a man, critically wounding two others and grazing the president’s ear, according to authorities.

Crooks, 20, killed a 50-year-old father of two named Corey Comperatore and sent David Dutch, 57, and James Copenhaver, 74, to the hospital with gunshot wounds, according to authorities. President Donald Trump, who was vying to return to office at the time, ducked for cover and had blood visible on the side of his face when he got back up.

While a recent New York Post op-ed called for the government to release more information on the case, it also argued that the lack of transparency has allowed conspiracy theories to swirl.

SCRUTINY INTENSIFIES OVER SECURITY LAPSES SURROUNDING THE CHARLIE KIRK SHOOTING

Then-Republican presidential candidate Donald Trump is whisked away by Secret Service after shots rang out at a campaign rally at Butler Farm Show Inc. on July 13, 2024, in Butler, Pennsylvania.  (Jeff Swensen/Getty Images)

Then-Republican presidential candidate Donald Trump pumps his fist as he is rushed offstage by U.S. Secret Service agents after being grazed by a bullet during a rally on July 13, 2024, in Butler, Pennsylvania.  (Anna Moneymaker/Getty Images)

“The danger Crooks posed was visible for years in public online spaces,” an unnamed source said to have uncovered more than a dozen of Crooks’ accounts told the paper. “His radicalization, violent rhetoric and obsession with political violence were all documented under his real name. The threat wasn’t hidden.”

Authorities told Congress they found no evidence that Crooks followed any particular ideology on his laptop, but according to the Post’s source, there was a clear timeline of Crooks’ changing ideology and violent rhetoric that remains to be addressed.

“The investigation, conducted by over 480 FBI employees, revealed Crooks had limited online and in person interactions, planned and conducted the attack alone, and did not leak or share his intent to engage in the attack with anyone,” FBI Director Kash Patel wrote on X Friday.

They conducted more than 1,000 interviews, he said, examined more than 2,000 tips from the public, seized 13 devices and reviewed half a million digital files. They uncovered 25 of Crooks’ accounts on social media platforms or online forums.

FLASHBACK: CHARLIE KIRK WARNED OF LEFT-WING ‘ASSASSINATION CULTURE’ MONTHS BEFORE HIS MURDER

Thomas Matthew Crooks pictured shortly before the assassination attempt on former President Donald Trump in Butler, Pennsylvania on Saturday, July 13, 2024. (Obtained by Fox News Digital)

Investigators believe Crooks planned the shooting alone, had no accomplices and did not speak about it with anyone. And unlike the 22-year-old Tyler Robinson charged with assassinating Charlie Kirk in September, Crooks died at the scene and never got back on Discord.

While the FBI has not publicly identified a political motive, Crooks’ online comments over several years shifted from pro-Trump to anti-Trump, according to digital records described in the Post. Whatever caused that remains unclear, but before he focused his murderous intent on the president, his posts about rage and violence were reportedly directed at Democrats.

“Trump bombed Iran to keep them from getting a nuclear weapon,” said Bill Gage, a former U.S. Secret Service agent and a consultant with SafeHaven Security Group. “What do you think he would do if he found out there was information that someone [or some] group was involved in his attempted assassination?”

CHARLIE KIRK’S ASSASSINATION LATEST CASE OF CONSERVATIVES BEING TARGETED FOR MURDER

Thomas Matthew Crooks, seen in this yearbook photo, graduated from Bethel Park High School with the Class of 2022. Two years later, he was shot and killed after opening fire at a Trump rally in Butler, Pennsylvania. (Bethel Park School District)

He said that online speculation suggesting Crooks had worked with anyone else doesn’t make enough sense to consider seriously.

“One big problem with conspiracies is that you have to dream up other conspiracies to explain away gaps in your original conspiracy,” he told Fox News Digital. “To think that a foreign intelligence agency, terror group or anyone else was involved in this and then think that a secret cabal of shadow government officials is keeping it quiet defies logic.”

Authorities have said Crooks had no criminal history and no documented mental illnesses. The murder weapon was purchased legally by his father in 2013.

TRUMP DEFENDS LABELING ANTIFA A ‘TERRORIST ORGANIZATION’ AS HE TARGETS LEFT-WING EXTREMISM

A large crowd waits for the arrival of then-Republican presidential candidate Donald Trump at a rally in Butler, PA, on Saturday, October 5, 2024. (Matthew McDermott for Fox News Digital)

However, during a congressional briefing in July 2024, senators were told that Crooks wrote a threatening message on “Steam,” an online gaming platform ahead of his shooting, Fox News reported previously.

“July 13 will be my premiere, watch as it unfolds,” he wrote, according to sources who attended the briefing.

When investigators reviewed his laptop, they found a few searches in July of: Trump, Biden, when is DNC convention, and July 13 Trump rally. They also found Crooks had two cellphones — one recovered from the scene, and another with just 27 stored contacts that they found at his home.

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“The internet is too big of a place,” Gage said. “Crooks was a mentally ill loner that slipped through the cracks. We will most likely never know his true motivations.”

Fox News’ Jacqui Heinrich contributed to this report.