Russian scientist at Harvard cleared of smuggling charges over frog embryos

Federal prosecutors have dropped all criminal charges against a Russian researcher who was placed in an immigration jail after bringing frog embryos through a Boston airport for cancer research at Harvard Medical School.Kseniia Petrova, 31, was detained for four months after she was arrested in early 2025 as she returned from France, where she obtained research samples from a laboratory specializing in splicing superfine sections of frog embryos.After customs officials questioned her at Logan International Airport, authorities charged her with smuggling, concealing facts, and making false statements to federal officials.A federal judge granted the government's motion to dismiss the case on Wednesday. Petrova told The Associated Press in an interview that she did not know she had to declare the samples and was not trying to sneak anything into the country.The prosecution faltered in April after a federal judge ruled that a customs officer improperly canceled Petrova's visa. She had voiced fear over potential deportation to Russia and subsequent imprisonment.Her defense team argued the case was vindictive, asserting the government brought criminal charges only after her immigration case appeared likely to succeed, and noted such criminal prosecutions are rare.Frog Embryo Researcher (Copyright 2026 The Associated Press. All rights reserved.)On Tuesday night, U.S. Attorney Leah Foley requested the dismissal "based on developments in this case and an assessment of the office’s priorities and resources."Foley stated that "At this stage, the resource costs of continuing this prosecution outweigh the public interest in its resolution," while maintaining that the "defendant’s claims of vindictive and selective prosecution are meritless."U.S. District Judge Leo Sorokin, who was nominated by former President Barack Obama, dismissed the charges on Wednesday without a hearing.Defense attorney Daniel Marx criticized the decision to prosecute in a statement, saying, "The DOJ never should have brought this highly unusual ‘smuggling’ prosecution against Kseniia Petrova, a talented scientist at Harvard," and adding, "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."The Department of Homeland Security previously defended Petrova's detention, alleging she lied to federal officers about the embryos.In filings, Foley cited an April ruling granting defense lawyers broad access to government records regarding comparable customs encounters, writing: "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.”