Thomas Matthew Crooks apparently teased an attack online days before he climbed onto a roof and opened fire at a Pennsylvania campaign rally, killing one and injuring others, including former President Donald Trump, Fox News has learned.

Secret Service and FBI officials told U.S. senators during an all-members briefing on Wednesday, July 17, that Crooks, 20, wrote a threatening message on the gaming platform "Steam" days before the attempted assassination in Butler, Pennsylvania, on July 13, Fox News’ Jacqui Heinrich reported.

According to the officials, Crooks allegedly wrote: "July 13 will be my premiere, watch as it unfolds."

"Steam" is a popular platform where tens of millions of gamers purchase games and communicate. The discovery was made as investigators continue to review Crooks’ technological devices, including his cell phones and laptop.

SECRET SERVICE CONTINUES TO FACE QUESTIONS AS FBI INVESTIGATES TRUMP SHOOTER THOMAS MATTHEW CROOKS

When investigators reviewed the laptop, they found a few searches in July of: Trump, Biden, when is the DNC convention, and the July 13 Trump rally, America’s top security officials told the senators on Wednesday.

The investigators found no evidence of a particular ideology on the laptop, which the FBI believes is notable, and nobody in interviews reported Crooks discussing politics, according to senators who spoke with Fox News after the meeting.

The senators also learned that the suspect had two cell phones. The primary phone was recovered from the scene along with a remote transmitter.

TRUMP SHOOTER'S PARENTS CALLED POLICE HOURS BEFORE ASSASSINATION ATTEMPT

A second cell phone found at the home had only 27 contacts. The FBI is in the process of tracking down and interviewing those people, they told the senators.

The development comes just hours after it was learned Crooks' parents contacted law enforcement on Saturday hours before the attempted assassination.

The would-be assassin's mother and father told local police that Crooks was missing and that they were concerned about his welfare, a source told Fox News.

It remained unclear if they knew that he was in possession of an AR-15 rifle that belonged to his father.

CLICK HERE TO GET THE FOX NEWS APP

Police have not said what actions they took after they were contacted.

Fox News’ Rebecca Rosenberg, Jake Gibson and David Spunt contributed to this report.

So, the more the outside world notices how senile Biden is, the more he retreats from reality. Lucky for him, that's a very short walk. According to the New York Times, Old Joe isn't consulting with any of his advisers or staff anymore. His cell phone rings and rings, but Joe keeps trying to answer a banana. True, Biden's inner circle is tighter than a meerkat's butthole. Don't ask me how I know. He needed a suppository. Apparently, he's down to a tiny group of loyalists, including his son and wife. The fate of the world hangs in the balance, and the people in charge are a substitute teacher and a guy who snorts grated cheese. I guess Bert and Ernie were all tied up. But hey, why listen to the advisers in a crisis, when you can rely on a convicted felon who smokes crack like it's brisket in North Carolina? 

The Biden's are running the government like their sex lives: they prefer relatives. So, as Joe Biden's brain shrinks like Jesse Watters' package in a swimming pool, so do his allies, and he closes himself off from facts that upset him. Like, Mr. President, your polls are awful. Your uncle wasn't eaten by cannibals. And, Joe, you have applesauce in your eyebrows. Biden is so desperate he's now targeting the Supreme Court, finalizing a proposal that includes term limits for the judges. 

Biden talking about term limits? It's like Stormy Daniels talking about sperm limits. I blame that on Joe Mackey. It's not likely to pass in Congress, but if it did, where does the appeal go? Back to the Supreme Court? So do they decide if they get to fire themselves? That's like the president deciding that he doesn't have dementia. Meanwhile, during a speech at the convention for the NAACP, Joe lied about the George Floyd riots, calling them peaceful protests.

JOE BIDEN: And if you peacefully protested George Floyd's murder, Donald Trump called for the National Guard to go after you. What the hell is the matter with this man?

‘DEFENSIVE’ BIDEN LASHES OUT AT VULNERABLE DEMS WARNING OF NOVEMBER LOSSES: REPORTS

$2 billion worth of damage is peaceful? That's like saying Jonestown was just a slumber party. But once again, Joe lied. 19 people were killed in the first two weeks of the 2020 riots, and Trump called on the National Guard to quell the violence in Portland but Democratic leadership turned it down. But Joe doesn't care because all he has left is race-baiting. And now he admits he ran as a transitional candidate but won't leave because he didn't expect it to be this divided.

JOE BIDEN: Look, when I originally ran, you may remember I said I was going to be a transitional candidate. I thought that I'd be able to move from this, just pass it on to someone else. But I didn't anticipate things getting so, so, so divided.

He's surprised by this division? He's like an arsonist who didn't expect it to get so hot. This guy s*** himself, both literally and figuratively. And now Biden also has a disastrous Zoom call with congressional Democrats over the weekend that was even worse than the debate. And I pissed out kidney stones that weren't as bad as the debate. During the call, Biden yelled at Colorado Democrat Congressman Jason Crow, a veteran and former recipient of the Bronze Star, telling Crow, "Tell me who did something that you've never done with your Bronze Star, like my son." What that has to do with anything not even Joe could explain to you. But that's his default way to get out of a debate. No one wants to say to him, what does your dead son have to do with this? 

SCHUMER ‘FORCEFULLY’ TOLD BIDEN HE SHOULD DROP HIS RE-ELECTION BID: REPORT

Reportedly, the Zoom call made Democrats so angry, the only reason they didn't lash out at Biden publicly was because less than an hour later, Trump was shot. You know your campaign is in deep trouble when your opponent almost getting assassinated can only help you. People were suddenly talking about Joe's idiocy instead of his dementia. So, how much longer can Joe hold out? 

He's supposed to debate Trump again on September 10th. Will he still be the candidate by then? Will he still even be the president by then? If you saw him crawling his way up the stairs of Air Force One today, you'd tell Covid, get out of him while you still can.