MOSCOW -- A judge issued an acquittal on Friday of the only official to have gone to trial in Russia in the case of Sergei L. Magnitsky, a lawyer whose death in prison three years ago inspired the United States Congress to pass a law addressing human rights abuses in Russia.
The official, Dr. Dmitry Kratov, the former head of the medical service at Butyrka Prison, where Mr. Magnitsky had been held, was accused of negligence for refusing repeated requests for treatment for a life-threatening illness.
Charges against another doctor had been dismissed earlier, elevating the significance of Dr. Kratov's trial, coming just weeks after Congress passed the Magnitsky Act, which was critical of the Russian courts for failing to prosecute any suspects in the lawyer's death.
But far from pursuing the case, prosecutors announced at a hearing on Monday that they would no longer press for a conviction and instead asked the judge, Tatiana Neverova, to acquit Dr. Kratov.
That reversal came four days after President Vladimir V. Putin said at a news conference that Mr. Magnitsky had died of natural causes, a statement that a lawyer for the family said had sent a message to prosecutors to drop the case.
In granting the prosecutor's request for an acquittal, Judge Neverova also indicated that Dr. Kratov could sue the government for damages under a Russian law related to illegal prosecution, Interfax reported. Dr. Kratov told journalists at the Tverskoi Court that he had not decided whether to sue.
The judge said she had seen no evidence in the course of the proceedings incriminating Dr. Kratov or convincing her that any connection existed between his actions and Mr. Magnitsky's death, Interfax reported.
Dr. Kratov was the only person on a list of 60 Russian officials implicated in the Magnitsky case by the United States Helsinki Commission to have stood trial in Russia. Fewer than 1 percent of suspects are acquitted in Russian criminal trials.
Nikolai Gorokhov, a lawyer representing the Magnitsky family, said that Dr. Kratov had signed documents refusing Mr. Magnitsky's request to be moved to an infirmary and that he had been aware of a diagnosis of pancreatitis and gallstones five days before Mr. Magnitsky death.
In the United States, the Magnitsky Act bans suspects like Dr. Kratov from entering the country and freezes assets in the American banking system.
In retaliation, Mr. Putin signed the Dmitri Yakovlev Act on Friday, named for a Russian child adopted in the United States who died after being forgotten in a hot car. The law bans Americans from adopting Russian orphans because of cases of abuse like Dmitri's.
Mr. Magnitsky's employer, the hedge fund Hermitage Capital, issued a statement Friday calling the ruling "a total miscarriage of justice."
"There is no doubt that people responsible for Magnitsky's death are being protected by the president of Russia," the statement said. "Now that President Putin is personally involved in the obstruction of justice in a major case of extrajudicial killing, he will have to face the consequences of his actions."
This article originally appeared in The New York Times.