Many questions remain about the recent assassination attempt on former President Donald Trump which left a man dead and others wounded.

However, federal authorities revealed this week that Trump's shooter appears to have left behind a message. 

Post made on gaming platform

According to Fox News, that discovery was presented to Capitol Hill lawmakers by Secret Service and FBI agents during a closed-door meeting on Wednesday.

The agents explained that 20-year-old Pennsylvania resident Thomas Matthew Crooks made a post on the gaming platform "Steam" just days before he opened fire on the former president.

"July 13 will be my premiere, watch as it unfolds," Crooks wrote. July 13 was the date of Trump's campaign rally in Butler, Pennsylvania.

The post was discovered after officials gained access to Crooks' electronic devices. Law enforcement agents also found records of internet searches concerning Trump's rally, President Joe Biden, and the Democratic National Convention (DNC).

Security concerns "were strictly turned down"

The revelation came even as complaints are still being raised about the security lapses that allowed Crooks to nearly murder the former president.

Firefighter and Pennsylvania Republican activist Zach Scherer has been to at least 20 of Trump's rallies, and he told Fox News that security at the event on Saturday seemed lax.

"Friday night; I'll take it back a day -- there was a group of us that had volunteered on the Trump campaign to do rally set up, which included setting up the barricades, the stage set-up and other things that were needed to make sure this was a successful event," Scherer recalled.

"We did a walk through at 7 PM on Friday night, and we raised multiple concerns with the state GOP staff about parking, about security issues we saw, where there were a lack of barricades at," he explained.

"And all of our safety concerns that we brought up on Friday evening were strictly turned down and there were no answers given to any of our questions or concerns about security in that matter," he added.

Secret Service director says "sloped roof" was "a safety factor"

For her part, Secret Service Director Kimberly Cheatle faced condemnation for telling ABC News that the building Crooks fired from could not be secured because of its "sloped roof."

"That building in particular has a sloped roof at its highest point. And so, you know, there's a safety factor that would be considered there that we wouldn't want to put somebody up on a sloped roof," Fox News quoted Cheatle as saying.

Donald Trump Jr. was quick to reject Cheatle's claim, telling Fox News host Sean Hannity, "Like, that's nonsense. That's not an excuse. It's the dumbest excuse."