Federal Prosecutors Move to Drop Criminal Charges Against HMS Researcher Kseniia Petrova

Federal prosecutors asked a judge on Tuesday to dismiss the criminal case against Kseniia Petrova, the Harvard Medical School researcher who has been fighting deportation proceedings since February 2025.

In the filing, Massachusetts U.S. Attorney Leah B. Foley requested to dismiss the case, writing that “the resource costs of continuing this prosecution outweigh the public interest in its resolution.” Prosecutors filed to dismiss the case with prejudice, which would prevent future charges from being filed.

The filing defended the original decision to charge Petrova for smuggling, and maintained that her claims of vindictive and selective prosecution were “meritless.” But, prosecutors argued that fighting those claims would “divert significant time and attention from more substantial federal interests.”

Petrova, a Russian national, was first arrested at Boston Logan International Airport in February 2025 when returning from a research trip to France, when Customs and Border Protections officers canceled her visa over her failure to declare frog embryos she said she intended to use in her work. Officers claimed that Petrova intentionally lied to officers about the contents of her bags — a claim she has since denied.

She was held in Immigration and Customs Enforcement custody in Vermont and Louisiana for four months before her release was ordered in May 2025. But prosecutors pressed criminal smuggling charges against her earlier that month, and Petrova remained in criminal custody after being released on bail from ICE custody. She was released from federal custody last June. Two weeks after her release, a grand jury indicted Petrova on the smuggling charge and two additional counts of making false statements to officers.

Petrova has since claimed that she was prosecuted vindictively, arguing that the criminal charges were filed as retaliation after she fought the immigration proceedings. In April, a federal judge allowed a request from Petrova’s lawyers to access government documents for other similar cases to support the claim.

The government’s attempt to appeal the discovery order was denied on Oct. 8. But instead of complying with the order and providing the documents, the government moved to dismiss the suit.

In the Tuesday filing, the government wrote that compliance with the order would require granting Petrova’s requests for “policies and procedures concerning CBP’s border inspections, some of which contain non-public information about CBP operations and investigative techniques.”

William Fick, Petrova’s attorney, wrote in a Wednesday statement that they “are pleased the DOJ has finally reached the appropriate conclusion and asked the court to immediately dismiss all criminal charges” against Petrova.

Petrova’s case has garnered national attention, coming amid both the Trump administration’s nationwide immigration crackdown and attacks on Harvard’s federal research funding and international students.

In the months after she was detained by immigration authorities, Massachusetts Attorney General Andrea J. Campbell filed an amicus brief in support of Petrova. Seventeen U.S. senators also sent a letter demanding her release to then-Secretary of Homeland Security Kristi Noem and then-Acting Director of Immigration and Customs Enforcement Todd M. Lyons.

“Throughout these proceedings, Ms. Petrova has shown tremendous courage, and we are relieved that this chapter of her terrible ordeal will soon be over,” Fick wrote.

—Staff writer Riya S. Shah can be reached at [email protected] and on Signal at riyas.23. Follow her on X @RiyaShah233.