Federal prosecutors submitted a filing Friday morning requesting a 60-day delay in a series of cases related to the Jan. 6 Capitol riot, describing the massive undertaking as "likely the most complex investigation ever prosecuted by the Department of Justice."

The big picture: More than 300 suspects have been charged in connection with the attack, which FBI Director Christopher Wray has described as "domestic terrorism."

• In addition to individual crimes like assault, trespassing and destruction of government property, federal prosecutors are investigating "conspiratorial activity" that began before Jan. 6.
• The Justice Department expects that at least 100 more individuals will be charged, according to the filing.

By the numbers: A total of more than 900 search warrants have been executed in nearly every state and Washington, D.C. Documents and evidence compiled by investigators across dozens of federal and local law enforcement agencies include:

• More than 15,000 hours of surveillance and body-worn camera footage from the day of the attack.
• Approximately 1,600 electronic devices and the results of hundreds of searches of electronic communications providers.
• Over 210,000 tips, "of which a substantial portion include video, photo and social media."
• Over 80,000 reports and 93,000 attachments related to interviews of suspects and witnesses.

The bottom line: "The investigation and prosecution of the Capitol Attack will likely be one of the largest in American history, both in terms of the number of defendants prosecuted and the nature and volume of the evidence," prosecutors wrote.

Driving the news: The request for a delay comes one day after the swearing-in of President Biden's new Attorney General Merrick Garland, who has pledged to make the Capitol riot investigation a top priority.

Read the full filing.