"We continue to gather evidence, as well as evidence already obtained as part of the ongoing investigation," said US lawyer Robert K. Hur in his release.
If Hasson is convicted, he faces a maximum jail term of 10 years for all three firearms and mufflers charges and one year for possession of tramadol, the statement said.
CNN left messages to Hasson's lawyer asking for comments on the charges Wednesday night.
Hasson, a so-called white supremacist, arrested on February 15, appears to have been inspired by the manifesto of Anders Breivik, a Norwegian man convicted in 2011 of two terrorist attacks that killed 77 people, according to court documents.
The list of alleged Hasson victims included Democratic politicians – Representative Alexandria Ocasio-Cortez of New York, Sensitive Chuck Schumer of New York, Cory Booker of New Jersey, Richard Blumenthal of Connecticut and Kamala Harris of California. former Beto representative O 'Rourke of Texas – as well as journalists from CNN, Don Lemon, Chris Cuomo and Van Jones and Chris Hayes, Ari Melber and Joe Scarborough of MSNBC.
"The defendant is a national terrorist, determined to commit acts dangerous to human life that are intended to affect the conduct of the government," prosecutors wrote in court documents prior to Hasson's indictment.
While prosecutors claimed in court last week, and in a detention note, that Hasson should be detained because he poses a threat to his community, and that they have qualified him of "national terrorist", national terror is not a federal crime. The FBI Agents Association notes that, as national terrorism is not a federal crime, federal prosecutors often have to rely on charges other than terrorist, such as hate crimes or state laws.
Hasson's lawyer, the Deputy Federal Public Defender, Julie Stelzig, said at a hearing last week that it was "not criminal to think about negative thoughts about people … or catastrophic scenarios, "adding," We are not yet a society that criminalizes people their thoughts … or holds people back for their Internet searches. "
An indictment hearing before a US District Court in Greenbelt, Maryland, has not yet been scheduled, says the press release.
Mary Kay Mallonee, Sophie Tatum and Jessica Schneider from CNN contributed to this report.