Legal Outcome: Federal Judge Drops Frog Embryo Smuggling Case

A federal judge in Boston dismissed all criminal charges against a Russian-born scientist on Wednesday, ending a case that prosecutors argued centered on undeclared frog embryos. The decision came without a hearing, concluding a legal battle that had stretched back to the woman's return from France in early 2025.

Kseniia Petrova, who conducts cancer research at Harvard Medical School, faced three counts: concealment of a material fact, making a false statement, and smuggling goods into the United States. She had also been charged with smuggling prior to the indictment filed last year. Petrova told The Associated Press that she did not realize the items required a declaration and was not attempting to hide anything from officials.

The case started to unravel in April when a federal judge ruled that a customs officer had improperly canceled Petrova’s visa following the incident. She had been briefly detained by immigration officials and feared deportation to Russia, where she worried she might face imprisonment. Her legal team subsequently filed a motion to dismiss, arguing that the government prosecuted her selectively and vindictively because she was winning her immigration case.

Attorneys noted that criminal charges for this specific type of conduct are rare. Judge Leo Sorokin, nominated by former President Barack Obama, agreed with the defense's position regarding the case's trajectory. He cleared Petrova of all accusations on Wednesday, removing the criminal burden from the researcher.

Daniel Marx, one of Petrova’s attorneys, released a statement praising the decision. He stated that the Department of Justice should not have brought the prosecution against a talented scientist. Marx described the samples as inert, non-living, and non-toxic frog embryos that posed no danger to anyone while advancing medical research into aging.

The incident originated in early 2025 when Petrova returned from a vacation in France. She had stopped at a laboratory that specialized in splicing superfine sections of frog embryos and obtained a package of samples for her work. Customs agents questioned her about the samples at Boston Logan International Airport. A Department of Homeland Security spokesperson said earlier this year that she was lawfully detained for lying to federal officers about carrying substances into the country.

U.S. Attorney Leah Foley filed a motion to dismiss the case on Tuesday night. She cited developments in the case and an assessment of the office's priorities and resources as the primary reasons for the move. Foley wrote that the cost of continuing the prosecution outweighed the public interest in resolving it at this stage. She also stated that the defendant's claims of selective prosecution were meritless, despite the government's obligation to provide extensive discovery documents related to comparable passenger encounters.

The dismissal allows Petrova to continue her research at Harvard Medical School without the threat of criminal conviction. The decision marks the end of a multi-year legal process that involved both immigration and criminal proceedings.