Investigators have reportedly turned up more information about Thomas Matthew Crooks, the gunman who attempted to assassinate former President Donald Trump on Saturday.

Crooks conducted online searches on Ethan Crumbley, the mass shooter who killed four students and injured seven more at Oxford High School in Michigan. He also looked for information regarding Crumbley’s parents, who were recently prosecuted and convicted in relation to their son’s actions.

Investigators also found that Crooks took a screenshot of Trump’s speech at the rally in Butler, Pennsylvania, shortly before carrying out the shooting.

A week before the shooting, Thomas Matthew Crooks searched online for the date of the Democratic National Convention and where Trump planned to speak, as well as other searches for Trump and President Joe Biden.

These details were among those shared by FBI and US Secret Service officials in a Wednesday briefing with lawmakers and by additional people familiar with the investigation. The previously unreported readout documents the scope of the investigation, including an expanded timeline of the would-be assassin’s actions leading to up his assault and law enforcement’s failure to prevent it.

Investigators remain puzzled about possible motives for Saturday’s attempted assassination of the former president, finding little to point to political or ideological intentions for the attack.

Investigators have been digging through Crooks’ digital and real life to build a profile of the shooter. They appear to be theorizing that Crooks planned to carry out a mass shooting and that Trump may not have been the only intended target.

One emerging theory by investigators, based in part on the timing and subjects of his online searches, is that the shooter was looking to carry out a mass shooting and that the Trump event’s proximity and timing offered the most ready opportunity, according to a US official briefed on the matter.

Unlike other mass shooters who often leave behind manifestos or writings to explain their attack, Crooks left behind few clues, in his bedroom or online.

Crooks also conducted searches for other prominent political figures and looked up the date and, as noted above, the location of the Democratic National Convention. The FBI also discovered that Crooks visited the location of the Trump rally about a week before it was held and on the morning of the shooting.

It was reported earlier in the week that Crooks made a post on Steam, a popular gaming platform. However, the authorities later walked back that assessment.

Meanwhile, the Secret Service has faced scrutiny for its failure to stop the shooting before it happened despite being warned by people who saw Crooks on the roof of the building from which he fired on Trump.

Now, Senator Josh Hawley (R-MO) has learned from whistleblowers that most of the security detail for Saturday's Trump event were not even Secret Service but rather were drawn from the Department of Homeland Security's Investigations unit, leading to further questions regarding the adequacy of their training and preparedness for a large scale event involving a Secret Service protectee like the former president.

The motive for the shooting has still not been established, and law enforcement has been unable to ascertain Crooks’ political affiliation. Some reports suggested that he was a Republican voter. Others note that he made a donation to a progressive group. Others intimated that he may have disliked both parties and their politicians.