Federal Judge Dismisses Charges Against Harvard Scientist in Boston

A federal court in Massachusetts has dismissed criminal charges against Harvard University researcher Kseniia Petrova, ending a prosecution over alleged smuggling of frog embryos into the United States. District Judge Leo T. Sorokin issued the order Wednesday, November 4, 2026, one day after federal prosecutors requested that the case be dropped.

The dismissal followed a legal dispute over Petrova's claims that federal authorities had unfairly targeted her. According to prosecutors, their decision came after a federal magistrate judge issued an order in April allowing Petrova to obtain evidence supporting her allegations of vindictive prosecution.

In their court filing, prosecutors maintained that Petrova's allegations were "meritless." However, they argued that presenting evidence to counter those claims would require the disclosure of "non-public information" concerning investigative operations and techniques used by U.S. Customs and Border Protection.

Petrova's attorney, Daniel N. Marx, welcomed the court's decision and said his client had endured a difficult legal battle.

"Throughout these proceedings, Ms. Petrova has shown tremendous courage, and we are relieved that this chapter of her terrible ordeal is now over," Marx said in a statement Wednesday.

Marx also criticized the Justice Department's decision to prosecute the researcher, arguing that her scientific work did not justify criminal charges.

"The Department of Justice never should have brought this highly unusual 'smuggling' prosecution against my client, a talented scientist at Harvard University determined to advance medical research into aging that could benefit everyone," Marx said.

Petrova is a Russian-born biomedical researcher whose work focuses on aging research. Immigration authorities detained her at Boston's Logan Airport in February 2025 after she returned from Paris.

Following her detention, authorities canceled her J-1 scholar visa and placed her in immigration proceedings. Earlier in 2026, a judge in Vermont ruled that the cancellation of her visa had been unlawful.

Federal prosecutors filed criminal charges against Petrova in May 2025 while she remained in immigration detention. The case followed an airport inspection during which officers discovered clawed frog embryos, paraffin slides and other scientific samples in her possession.

Petrova maintained that the materials were connected to her scientific research. Marx argued that their handling presented no public safety concerns.

"Her handling of scientific samples — inert, non-living, non-toxic, frog embryos — never posed any danger to anyone," Marx said.

The defense also pointed to decisions by two federal judges that supported further scrutiny of the circumstances surrounding Petrova's prosecution.

Marx said those judges had determined that "the suspicious circumstances" surrounding the case warranted additional investigation into whether the Department of Homeland Security and the Department of Justice had "unfairly targeted" his client.

Although the dismissal ends the criminal prosecution, Marx said the broader question of whether federal agencies improperly targeted Petrova remains unresolved.

"Although that important question will not yet be answered, we are pleased the DOJ has finally reached the appropriate conclusion and asked the court to immediately dismiss all criminal charges against Ms. Petrova," Marx said.