Attorneys for Tornado Cash developer Roman Storm filed a motion asking the court to reconsider the motion to dismiss the case due to the prosecution withholding exculpatory evidence in the form of communications with the Financial Crimes Enforcement Network (FinCEN) dating back to 2023.

According to a May 16 letter from Storm's attorneys to Judge Katherine Polk Failla, the FinCEN documents show that non-custodial crypto mixers do not fall under the legal definition of a "money transmitting business" and that prosecutors have known this since at least 2023.

Despite having knowledge of the FinCEN guidance on crypto mixers, state prosecutors still proceeded with cases against the Samourai Wallet developers and Tornado Cash, the attorneys alleged.

US prosecutors denied they withheld the evidence, claiming they submitted the FinCEN communications within the stipulated timeframe to produce the documents for the defense and the court during legal discovery.

Storm's defense cited the same legal documents and the same argument the Samourai Wallet developer’s attorneys posed to the court in a May 5 legal letter. Storm's attorneys wrote:

"The disclosures in the Samourai case reveal that the government, at the very least, played fast and loose and, at worst, affirmatively misled this Court with its arguments about FinCEN guidance when responding to the motions to dismiss and to compel discovery."

The letter went on to argue that although the government continues to claim that the cases bear only "superficial similarities" to each other, they share the core characteristics of cryptocurrency mixers under the law, thus making the FinCEN documents salient to dismissing the case against Storm.

Roman Storm's trial moves ahead despite sanctions against Tornado ruled unlawful

Federal Judge Robert Pitman issued a ruling on April 28 denying the Office of Foreign Assets Control (OFAC) the ability to reimpose sanctions on Tornado Cash — setting a legal precedent for non-custodial mixer cases.

Despite this, US federal prosecutors still moved ahead with the case against Storm although the charges have been modified.