Roger Stone, a longtime adviser to President Donald Trump, speaks to the media outside court January 25, 2019 in Fort Lauderdale, Florida.

The evidence collected in the criminal case of President Donald Trump's longtime political advisor Roger Stone is "voluminous and complex," special counsel Robert Mueller said in a court filing Thursday.

Mueller said in the Washington, D.C., federal court filing that that evidence includes "multiple hard drives containing several terabytes of information," as well as search warrant documents, financial records and communications in a raft of electronic devices spanning "several years."

Read the filing here.

The special counsel requested that U.S. District Judge Amy Berman Jackson label the case "complex" in light of the scope of the potential evidence. Doing so would exempt the case from the time constraints of the 70-day "speedy trial period."