The United States Department of Justice (DOJ) opposed a Motion to Dismiss conspiracy and money laundering charges against Roman Semenov, co-founder of Tornado Cash. According to the prosecutors, the defense's filing presented disputed facts that are better suited for jury consideration at a later stage.

In the DOJ’s response document, the prosecutors explained why Roman Semenov should be held accountable for the alleged crimes related to Tornado Cash. The DOJ disputed the defense's description of Tornado Cash, highlighting its establishment in 2019 as a mixing service with various components.

Roman Semenov and Roman Storm were accused by the DOJ of engaging in money laundering, operating an unlicensed money transmitter, and breaching sanctions through the creation of Tornado Cash. The U.S. authorities alleged that groups like North Korea’s Lazarus Group utilized Tornado Cash to launder money.

Despite Storm pleading not guilty to the charges and being released on bail, his lawyers later sought to dismiss the indictment, claiming insufficient grounds for the charges. Semenov emphasized his role in code design but denied responsibility for the service's use.

Semenov's legal team argued that Tornado Cash does not function as a custodial mixing service and does not meet the standards of a financial institution. They asserted that Storm had no means of controlling the service to prevent its misuse by entities like Lazarus Group.

The prosecutors led by Damian Williams contended that Semenov was responsible for overseeing the crypto mixer and creating systems that facilitated criminal anonymity. They criticized Tornado Cash's co-founders for failing to implement adequate measures to exclude sanctioned addresses.

The U.S. government's actions against crypto-mixing services have escalated as seen in the recent arrest of Samourai Wallet’s co-founders. They were charged with conspiracy to commit money laundering and conspiracy to operate an unlicensed money transmitting business.

Ki Young Ju, CEO of CryptoQuant, defended crypto mixing services, stating they are not inherently unlawful in response to the arrests linked to Samourai Wallet.