He registered using a coded email address and phone number, sources said.
A source familiar with the matter told ABC News that a person claiming to be the 20-year-old Pennsylvania man who attempted to assassinate former President Donald Trump signed up online to attend a pro-Trump rally in Butler, Pennsylvania on July 6, a week before the shooting.
Sources said the individual registered using a coded email address and mobile number.
According to sources, the person registered online using email and a mobile phone three days after the Trump campaign announced on July 3 that the rally would be held on July 13.
Federal authorities said suspect Thomas Matthew Crooks attempted to assassinate President Trump by shooting him in the ear at a rally on Saturday, in which one attendee was also killed.
Officials said the building where the suspect ultimately opened fire was outside the security perimeter but within 400 feet of the podium where Trump was speaking.
ABC News previously reported that sources said Crooks had searched for images of President Joe Biden and former President Trump on his phone, as well as dates for Trump’s rally in Butler and the Democratic National Convention in Chicago.
A search of Crooks’ phone records did not reveal any indication of his political views, and investigators are still trying to determine his motive.
The motive for the assassination attempt remains a mystery, and no ideological ties to Trump or Biden have been identified, the report’s authors said.
The FBI told lawmakers it had conducted 200 interviews as part of its investigation, sources said.
An FBI spokesman did not respond to an email from ABC News seeking comment.
