Federal judge dismisses case against Russian-born scientist accused of smuggling frog embryos

BOSTON (AP) — A federal judge on Wednesday granted a government motion to dismiss all charges against a Russian-born scientist who was accused of smuggling frog embryos into the United States.

Kseniia Petrova, who was conducting cancer research for Harvard Medical School, was indicted last year on one count of concealment of a material fact, one count of false statement and one count of smuggling goods into the United States. She had been charged with the smuggling before that.

She told The Associated Press in an interview that she did not realize the items needed to be declared and was not trying to sneak anything into the country.

The case began to fall apart in April, after a federal judge ruled a customs officer improperly canceled Petrova's visa over the incident. Petrova had been briefly detained by immigration officials and feared being deported to Russia and imprisoned there.

Then, Petrova’s lawyers filed a motion to dismiss, arguing the government was selectively and vindictively prosecuting her and that was unconstitutional. They argued that the government only filed criminal charges after it looked like she would win her immigration case. They also argued it was rare for anyone to be charged criminally for what Petrova did.

Federal District Judge Leo Sorokin, who was nominated by former President Barack Obama, dismissed all the charges against Petrova on Wednesday without a hearing.

“The DOJ never should have brought this highly unusual “smuggling” prosecution against Kseniia Petrova, a talented scientist at Harvard,” one of Petrova's attorneys Daniel Marx said in a statement. “Ms. Petrova only sought to advance medical research into aging that could benefit everyone, and her handling of scientific samples — inert, non-living, non-toxic, frog embryos — never posed any danger to anyone.”

In early 2025, Petrova was returning from a vacation in France, where she had stopped at a lab specializing in splicing superfine sections of frog embryos and obtained a package of samples for research. She was questioned about the samples while passing through a customs checkpoint at Boston Logan International Airport.

Petrova was “lawfully detained after lying to federal officers about carrying substances into the country,” a spokesperson for Department of Homeland Security said earlier this year. The Trump administration was committed to “restoring the rule of law and common sense to our immigration system,” the statement said. The department includes Customs and Border Protection.

But on Tuesday night, U.S. Attorney Leah Foley filed a motion to dismiss the case “based on developments in this case and an assessment of the office’s priorities and resources.”

“At this stage, the resource costs of continuing this prosecution outweigh the public interest in its resolution,” she wrote, adding that the “defendant’s claims of vindictive and selective prosecution are meritless.”

Among the reasons for the dismissal, Foley wrote, was an April court ruling which granted the “defendant broad discovery in support of a selective prosecution” as well as documents related to comparable cases and also Customs and Border Protection policies and procedures.

“The government must supply the defendant with information pertaining to any number of passenger encounters involving undeclared items that could be considered comparable, without regard for the manner in which those items were carried, the presence or absence of planning, or the strength of the evidence of a passenger’s fraudulent intent,” Foley wrote.