A dual Russian-Swedish national was convicted Tuesday in U.S. federal court for operating a notorious cryptocurrency mixer that moved about $400 million in bitcoin over the course of a decade.

Roman Sterlingov, 35, was arrested in April 2021 in Los Angeles on suspicion that he was behind the Bitcoin Fog mixer, a service used by hackers to obfuscate the origins of cryptocurrency. According to the complaint, Sterlingov took commissions of 2 to 2.5 percent on transactions.

“Over the course of its decade-long operation, stopped only when Sterlingov was arrested and detained, Bitcoin Fog moved well over 1.2 million bitcoin (BTC) – valued at approximately $400 million at the time of the transactions,” the Department of Justice said in a release announcing the conviction.

“The bulk of that cryptocurrency came from darknet marketplaces and was tied to illegal narcotics, computer fraud and abuse activities, and identity theft.”

Sterlingov’s anonymizer service was found to have sent or received at least $78 million in transactions involving darknet markets.

Represented by famous hacker lawyer Tor Ekeland, Sterlingov reportedly admitted to using the service but denied being its operator or founder. His defense alleged that the blockchain analysis underpinning the case was faulty and Ekeland pledged to appeal in a post on X (formerly Twitter).

Ilya Lichtenstein, the convicted hacker behind the heist of the Bitfinex cryptocurrency exchange, testified during the trial that he used the Bitcoin Fog mixer to conceal some of the stolen funds, although he did not correspond directly with Sterlingov.

Sterlingov was found guilty of “money laundering conspiracy, sting money laundering, operating an unlicensed money transmitting business, and violations of the D.C. Money Transmitters Act.” Each of the money laundering convictions carry maximum 20-year sentences. He will be sentenced in July.

Law enforcement has set its sights recently on the infrastructure that enables cybercrime to flourish. In September of this year, the alleged co-founder of the mixer Tornado Cash will face a criminal trial.

The mixer is suspected of facilitating more than $1 billion in transactions for money laundering, including hundreds of millions for North Korea’s Lazarus Group.