Prosecutors say Samourai’s Whirlpool and Ricochet tools were built to hide Bitcoin trails, processing 80,000 BTC in ways that evaded safeguards.
Hill and Rodriguez promoted the mixer for illicit use and earned over $6M in fees before pleading guilty to lesser charges.
Internal chats showed the founders knew criminals used Samourai, with Rodriguez calling mixing “money laundering for bitcoin.”
William Lonergan Hill, the Chief Technology Officer and Co-Founder of the cryptocurrency mixing service Samourai Wallet, has been sentenced to four years in federal prison for helping criminals hide more than $237 million in illegal funds.
A federal judge in New York delivered the sentence, noting that Hill’s actions made it significantly harder for victims of hacks, fraud schemes, and other crimes to ever recover their stolen money.
Hill pleaded guilty earlier this year to conspiring to operate an unlicensed money-transmitting business. Prosecutors said Samourai Wallet was built to obscure Bitcoin (BTC) movement in ways that deliberately bypassed financial safeguards.
The four-year sentence comes after Keonne Rodriguez, CEO and Co-Founder of the Samourai Wallet, was sentenced to five years in federal prison on November 6. In addition to their prison time, both men have been ordered to serve three years of supervised release and pay $250,000 each in fines. They also forfeited more than $6.3 million, the fees Samourai earned, toward a larger forfeiture order tied to the criminal proceeds moved through the platform.
In the sentence, prosecutors said Samourai Wallet was engineered to obscure Bitcoin transfers and evade financial safeguards, making it difficult for law enforcement and exchanges to trace suspicious transactions.
Two key features drove this effort. “Whirlpool,” a mixing service launched in 2019, shuffled Bitcoin between groups of users so the original source of the coins disappeared within the blockchain.
Another tool, “Ricochet,” added extra, unnecessary hops to a transaction to break the link between a sender and receiver. Together, these features processed more than 80,000 BTC, worth over $2 billion at the time, and generated more than $6 million in fees.
Evidence of encouraging criminal use
Investigators also pointed to messages and online posts showing that Hill and Rodriguez actively encouraged criminal use. Hill advertised the service on the darknet forum Dread, telling users looking to “clean dirty BTC” that Samourai’s Whirlpool tool was the better option.
In 2020, Rodriguez also urged hackers behind a major social media breach to channel stolen funds into the mixer, later expressing disappointment when they chose another service.
Internal communications showed the Co-Founders fully understood how Samourai was being used. In one WhatsApp exchange, Rodriguez described mixing as “money laundering for bitcoin,” and Samourai’s marketing materials acknowledged that part of its customer base consisted of dark-market participants moving illegal proceeds.
The investigation involved cooperation from the Internal Revenue Service (IRS), Federal Bureau of Investigation (FBI), Europol, Icelandic authorities, and Portuguese law enforcement, who helped secure Hill’s extradition from Portugal in 2024.
The case has drawn significant attention in the crypto world because it raises major questions about privacy tools. Prosecutors argue that if a service is designed to help hide criminal money, it clearly breaks the law, regardless of the technology used.