Operator of Helix Darknet Cryptocurrency ‘Mixer’ Sentenced in Money Laundering Conspiracy Involving Hundreds of Millions of Dollars

WASHINGTON - Larry Dean Harmon, 41, of Akron, Ohio, was sentenced today to three years in prison for his operation of the darknet cryptocurrency "mixer" Helix, which processed transactions involving over $300 million worth of cryptocurrency from 2014 to 2017.

The sentence was announced by U.S. Attorney Matthew M. Graves for the District of Columbia; Principal Deputy Assistant Attorney General Nicole M. Argentieri, head of the Justice Department's Criminal Division; Chief Guy Ficco of the IRS Criminal Investigation (IRS-CI); and Assistant Director Bryan Vorndran of the FBI's Cyber Division.

Harmon pleaded guilty on August 18, 2021, to conspiracy to commit money laundering.

According to court documents, Harmon ran Helix, a darknet mixer that laundered customers' bitcoin. Helix was connected to Grams, a darknet search engine also run by Harmon. Helix was one of the most popular mixing services on the darknet and was highly sought after by online drug dealers who needed to launder their illicit proceeds. Helix processed at least approximately 354,468 bitcoin - the equivalent of approximately $311,145,854 in U.S. dollars at the time of the transactions - on behalf of its customers, including customers in the District of Columbia. Much of those funds were coming from or going to darknet drug markets. Harmon retained a percentage of these transactions as his commissions and fees for operating Helix.

Harmon worked to ensure Grams and Helix connected to or otherwise supported all of the major darknet markets at the time. Harmon developed an Application Program Interface (API) to allow darknet markets to integrate Helix directly into their bitcoin withdrawal systems. Harmon also customized features of Helix to ensure compatibility with significant markets. Investigators traced tens of millions of dollars from darknet markets to Helix.

In addition to his term of imprisonment, Harmon was sentenced to three years of supervised release; a forfeiture money judgment in the amount of $311,145,854; and forfeiture of seized cryptocurrencies, real estate, and monetary assets valued at over $400 million.

The IRS-CI Cyber Crimes Unit and FBI Washington Field Office investigated the case, with valuable assistance provided by the Justice Department's Office of International Affairs and the U.S. Attorney's Office for the Northern District of Ohio.

The Attorney General's Ministry of Belize and the Belize Police Department provided essential support for the investigation, coordinated through the U.S. Embassy in Belmopan. The investigation was coordinated with the Financial Crimes Enforcement Network, which assessed a $60 million civil monetary penalty against Harmon in a parallel action.

Special Assistant U.S. Attorney Christopher B. Brown of the U.S. Attorney's Office for the District of Columbia and Trial Attorney C. Alden Pelker of the Criminal Division's Computer Crime and Intellectual Property Section (CCIPS) prosecuted the case. Trial Attorney Riane Harper and former Trial Attorney W. Joss Nichols of CCIPS, Paralegal Specialist Angela De Falco for the District of Columbia, and Assistant U.S. Attorney Daniel Riedl for the Northern District of Ohio provided valuable assistance.

19cr0395