A federal judge in Vermont has ruled that a customs officer unlawfully canceled the visa for a Russian-born Harvard Medical School scientist entering the United States at a Boston airport with frog embryo research samples.
Judge Christina Reiss’ order this week in federal court in Burlington is the latest turn in legal cases for Kseniia Petrova that have played out in civil and criminal courts in different states.
“The undisputed facts reveal that Ms. Petrova’s visa was impermissibly canceled because of the frog embryo samples and for no other reason,” Reiss wrote in the 21-page ruling.
Federal government lawyers, the judge added, did not provide any authority allowing a U.S. Customs and Border Protection officer to cancel Petrova’s J-1 work-study visa for a customs violation.
“They do not claim Ms. Petrova offered contradictory or fraudulent reasons for seeking to enter the United States, nor do they claim her reasons for seeking admission to the United States conflicted with the purposes of her J-1 visa,” the judge wrote.
Reiss’ ruling is the most recent in a string of decisions from federal judges in Vermont in high-profile cases dealing blows to immigration enforcement actions taken by the administration of President Donald Trump since he took office more than a year ago.
For example, federal Judge William K. Sessions III granted the release of a Tufts University student who had been held in ICE custody for a short time in Vermont. Also, Judge Geoffrey Crawford ordered the release of a Columbia University student who was living in Vermont when he was taken into ICE custody.
Reiss, the federal judge in Petrova’s case, called the action of the customs officer “arbitrary” and “capricious.”
According to Petrova’s attorney, often the penalty for failing to declare non-dangerous items is simply a fine or forfeiture.
Petrova, a genetics researcher, was taken into custody by federal customs officials in February 2025 when she arrived at Boston Logan International Airport from France and did not properly declare research samples — frog embryos, according to court records.
After the customs officer canceled her visa, Petrova was held in federal custody at the Vermont women’s prison in South Burlington for about a week before she was transferred to a U.S. Immigration and Customs Enforcement facility in Louisiana.
Petrova challenged her detention by filing a habeas corpus petition in federal court in Vermont while still in custody in the state, claiming she was being unlawfully held by federal authorities.
Petrova’s attorney wrote in a court filing in the Vermont case that the incident leading to her custody was an “inadvertent failure” to declare on a customs form frog embryos that she was bringing into the country from a research facility in France when she had traveled on vacation.
The request for the frog embryos came from the leader of a research group at Harvard Medical School “under whose leadership she works,” the filing added.
Reiss, in a ruling last May, ordered Petrova’s release from custody.
Although Reiss’ ruling this week was a victory for Petrova regarding the cancellation of her visa, she still faces federal criminal charges in Massachusetts alleging she tried to smuggle the frog embryos into the country.
Gregory Romanovsky, Petrova’s attorney, said in a statement that Reiss’ ruling was “an important step toward correcting what should never have happened in the first place.”
In January, he added, Petrova returned to her lab at Harvard, conducting scientific research.
Reiss’ ruling “makes clear that, as broad as CBP’s authority is at the border, its actions cannot be arbitrary or capricious,” Romanovsky said in the statement. “The United States remains a nation of laws — and those laws apply to all.”
U.S. Customs and Border Protection officials could not be reached Thursday for comment.
