Thomas Matthew Crooks' Home Had Over 12 Firearms Inside

As the investigation into Thomas Matthew Crooks, the 20-year-old who shot former President Donald Trump at a rally over the weekend, the FBI continues to uncover details surrounding his past.

As The Blast reported, Crooks opened fire approximately 10 minutes after Trump took the stage at an outdoor rally. The former President was seen grabbing his bleeding right ear and fell to the ground as Secret Service agents rushed to his side. While Trump survived the attempted assassination, one rallygoer did not, and two others are in critical condition.

After conducting more than 100 interviews and searching the suspect's home and vehicle, the FBI is still looking for the motive.

A search of the Crooks family home revealed over a dozen firearms, according to four senior officials speaking to NBC News.

Following the shooting incident, Crooks' father contacted the police, expressing concern that his son and an AR rifle were unaccounted for, as reported by three senior officials. The police then responded to the home after receiving the call.

As part of their investigation, the FBI found that Crooks purchased ammo the morning of the shooting but are still looking into whether some ammunition was bought in the days before the shooting.

"Over the last several months, Crooks received several packages, including some marked as possibly containing hazardous material, according to a review of his shipping history," an FBI and Department of Homeland Security bulletin said, per ABC.

Secretary of Homeland Security Alejandro Mayorkas spoke to George Stephanopoulos on "Good Morning America," where they admitted, "A direct line of sight like that to the former president should not [have] occur[ed]."

"That is precisely why President Biden directed that an independent review of the incident occur. That will be done in close coordination with the FBI, which is conducting a separate criminal investigation, the importance of which cannot be overstated," Mayorkas added.

"We have to learn everything about the assailant, who of course, the Secret Service so bravely and heroically neutralized, and we are going to really study the event independently and make recommendations to the Secret Service and to me so that we can assure the safety and security of our protectees, which is one of our most vital missions in the Secret Service, the Department of Homeland Security and across the government," Mayorkas said.

Not only did the Secret Service recover an AR-style rifle at the scene, but they also discovered explosive devices in the car Crooks had been driving.

"Suspicious devices found at both locations have been rendered safe by bomb technicians and are being evaluated at the FBI Laboratory," the FBI said, per ABC.

Preliminary investigations indicate that Crooks acted alone.

“At this time, the information that we have indicates that the shooter acted alone and that there are currently no public safety concerns,” FBI special agent in charge Kevin Rojek said earlier this week. “At present we have not identified an ideology associated with the subject, but I want to remind everyone that we’re still very early in this investigation.”

The AR-15-style rifle allegedly used by Crooks in the rally shooting had been legally purchased in 2013 by the suspect's father.

"At present, we have not identified an ideology associated with the subject," Kevin Rojeck, a special agent, said, per ABC. "But I want to remind everyone that we're still very early in this investigation."

The 20-year-old climbed on top of a roof located less than 150 meters (164 yards) from where Trump was speaking. Pennsylvania voter records indicate that a Thomas Matthew Crooks, sharing the same address and birth date, is registered as a Republican. Interestingly, he had previously made a $15 donation to a Democratic-aligned group.