Thomas Matthew Crooks, the 20-year-old who tried to kill former President Donald Trump at a Pennsylvania rally last weekend, purportedly wrote a threatening message on a gaming platform ahead of the shooting, Fox News reported.
"July 13 will be my premiere, watch as it unfolds," Crooks wrote on Steam, a popular online platform where gamers communicate.
The information was relayed Wednesday to U.S. senators during an all-member briefing by law enforcement officials on Crooks.
Crooks also had searched the dates of the Democratic National Convention and Trump's Pennsylvania rally on his phone, according to the report.
Crooks, who was identified as a person of interest about an hour before the shooting, used a sniper rifle from a rooftop across a field from the rally to fire off two quick volleys of rounds at Trump.
The former president was hit in the ear and one spectator died. Two others were injured. Secret Service snipers took Crooks out just 26 seconds later.
Witnesses and law enforcement officials say Crooks walked around for at least a half hour before climbing onto the roof of a building adjacent to the Butler Farm Show grounds, where Trump was speaking.