Investigators piece together the puzzling portrait of Trump’s would-be assassin

After conducting more than 200 interviews and combing through his phone and internet search history, federal investigators have pieced together an early portrait of the man who sought to assassinate former President Donald Trump: Thomas Matthew Crooks was an intelligent, unassuming loner, who expressed an interest in guns and was far from outspoken about politics.

But the emerging profile of Crooks nearly a week after the shooting has left authorities puzzled about a motive for his assault and has had investigators speculating that his intentions may have been less politically motivated and more about attacking the highest-profile target near him.

The investigation remains in its early stages, officials caution. Still, in some ways, Crooks seems similar to the dozens of other young men who've wreaked havoc across the US with high-powered assault-style rifles in recent years.

He had few close friends, he would often go shooting at a local firing range, and he didn't seem to display strongly held views that would suggest a politically driven assassination, according to CNN interviews with law enforcement and a review of notes from a briefing to Congress.

In addition to the former president, Crooks had searched online about President Joe Biden and had photos on his phone of other prominent figures from both parties.

He searched for the location of Trump's rally as well as the upcoming Democratic National Convention, the briefing notes say, and discovered that Trump planned to appear just an hour's drive away from his home in the Pittsburgh suburbs.

That suggests Crooks may have been looking to carry out a high-profile shooting, and the Trump event's proximity and timing offered the most accessible opportunity, federal officials have speculated.

"Even though he didn't get his primary target, the shooter was successful in a lot of ways because he got closer to doing something no one has done in decades," one federal official told CNN, referring to the assassination of a presidential candidate.

It remains unclear if Crooks intended to carry out a much larger attack and started with Trump because that was the way to gain the most notoriety.

Crooks had also searched for information on another recent mass shooter who shot and killed four classmates at a Michigan high school in 2021.

The web searches about that shooter, Ethan Crumbley, are consistent with what law enforcement officials have seen in other mass shooters who research people they wish to emulate, in part, as a way to form their own idea of how to do something bigger, the federal official said.

But there are also significant differences between Crooks' behavior and that of a typical mass shooter.

On the day of the attack, Crooks appeared to have been specifically targeting Trump – not aiming at the crowds in an attempt to kill as many people as possible.

While he had an improvised explosive in the trunk of his car, it's not clear if he planned to set it off to kill people or as a distraction.

Kathleen Puckett, a former FBI behavioural analyst who worked on the case of the "Unabomber" Ted Kaczynski, said that Crooks also appeared to have less firepower than many mass shooters, who often carry multiple weapons and wear body armour.

"It didn't look to me like he was ready for an assault," Puckett said, while noting the limits of publicly available information.

"It looked to me like he was taking a window that he saw a vulnerability in where he felt that he was unobserved to the extent he could get off some critical shots."

In addition, unlike other mass shooters who often leave behind writings to explain their attacks, authorities have thus far recovered few clues, in Crooks' bedroom or online.

That is frustrating experts who are trying to piece together his mindset – and raising comparisons with Stephen Paddock, the gunman who killed 60 people in Las Vegas in 2017.

Nearly seven years after America's deadliest mass shooting, investigators still do not know why Paddock pulled the trigger.

Like the Las Vegas massacre, "this may be a situation where the more we know, the less we understand about the exact reason why," said Juliette Kayyem, a former assistant secretary at the Department of Homeland Security and a CNN national security analyst.

Crooks' family members told investigators he did not openly discuss politics, and evidence recovered at his home shed no further light on his political values or ideology, according to a readout shared with CNN that details a briefing that FBI and US Secret Service officials gave lawmakers on Wednesday.

Mary Ellen O'Toole, a former FBI profiler, said that based on the evidence assembled so far, she thought that Trump's rally was "very appealing" to Crooks in part because it "fell in his backyard."

"This gave him incredible attention and catapulted him to a point where I think that's why he chose this," she speculated.

Still, Puckett called lone offenders – who largely remain invisible before attacks – "one of the prickliest problems out there" for law enforcement, and warned against a rush to find simple answers about Crooks' motive.

"Whatever his story turns out to be, it's not going to be simplistic, I don't think – it's going to be more complicated," Puckett said.

"You don't want the simplistic version. You want every detail you can find."