DC Circuit Upholds Chainalysis Reactor Admissibility Under Daubert Standard

A federal appeals court has affirmed the evidentiary reliability of blockchain tracking software Chainalysis Reactor, preserving a key prosecutorial tool across federal criminal litigation ¹. In September 2026, the U.S. Court of Appeals for the D.C. Circuit upheld a district court determination that Reactor easily satisfies the legal requirements of the Daubert standard, according to a statement published by Chainalysis on Oct. 13 ¹.

The challenge emerged from the criminal conviction of dual Swedish-Russian national Roman Sterlingov, who was found guilty of operating the mixer Bitcoin Fog ¹. Federal prosecutors utilized Reactor to trace transactions between Bitcoin Fog and darknet marketplaces, linking more than 900,000 $BTC addresses to the mixing service ¹. Sterlingov appealed the guilty verdict by contesting the admission of Reactor-based testimony presented by FBI Specialist Luke Scholl and Chainalysis analyst Elizabeth Bisbee ¹. Sterlingov argued the software lacked peer review and a determined error rate ¹.

Methodological Reliability Upheld

The appellate panel rejected those arguments, ruling that formal peer review is not mandatory for tools operating in novel and technical domains such as blockchain forensics ¹. The court emphasized Reactor's clustering methodology, which couples change-address analysis with digital fingerprinting to identify transaction patterns and behavioral characteristics ¹. Both Scholl and Bisbee testified that they could not identify an instance where a Reactor attribution was subsequently shown to be false ¹. Furthermore, the court determined that the software's conservative attribution philosophy supports legal reliability by favoring defensible links over speculative associations ¹.

The ruling marks the second federal judicial tier to endorse Reactor's evidentiary standing, following its initial district court validation in 2024 ¹. Chainalysis remains the only blockchain analytics vendor whose software has cleared Daubert scrutiny in federal court as of October 2026 ¹. The appellate precedent shields on-chain transaction tracing as verifiable evidence in U.S. prosecutions even as analytics firms integrate artificial intelligence workflows into forensic tracing ¹.