It won't bring back her husband, a former KGB agent who became a fierce Putin critic. Nor are the prime suspects in his death in custody. But at least the circumstances of the mysterious case have been made a little clearer.
"I believe that the truth has finally been uncovered," Marina Litvinenko said, speaking outside the Royal Courts of Justice on Friday after the final hearings in the year-long inquiry wrapped up. "The murderers and their paymasters have been unmasked."
In a deathbed statement, Litvinenko blamed Putin for ordering his poisoning by means of the rare radioactive substance polonium-210, saying it was slipped into his tea at a London hotel in 2006.
The Kremlin has always strongly denied the accusation, as have the two chief suspects, Andrei Lugovoy and Dmitri Kovtun.
But Marina Litvinenko and her legal team pointed the finger at Putin repeatedly in their statements as the hearing wrapped up.
"My husband was killed by agents of the Russian state in the first-ever act of nuclear terrorism on the streets of London," Marina Litvinenko said. "This could not have happened without knowledge or consent of Mr. Putin."
Litvinenko came to Britain in 2000 after turning whistleblower on the FSB, the KGB's successor. He is said by his widow to have been a British agent, with a handler at MI6, Britain's foreign security service.
Lawyer: Putin and his cabal 'willing to murder'
In his closing statement, the Litvinenko family's lawyer, Ben Emmerson, insisted that "no amount of synthetic defiance" from Putin could hide the truth revealed through the inquiry.
"The evidence has demonstrated, step by painstaking step, that Putin and his personal cabal are directly implicated in organized crime, that they are willing to murder those who stand in their way, and that Mr. Litvinenko was murdered for that reason," Emmerson said.
Kovtun was due to give evidence at the inquiry this week via video link from Russia but pulled out at the last moment, saying he couldn't do so without permission from Russian authorities.
The Russian Foreign Ministry said on its website that it had been forced to withdraw from the public inquiry last August, "solely due to the fact that despite it being called public, it is not transparent either for Russia or for the public."
Allowing Kovtun to give evidence via video link "would have contradicted the existing international agreements between Russia and Great Britain on legal assistance and police cooperation," it said.
Some of the evidence at the inquiry was heard behind closed doors because of concerns over national security.
Russia's state-run Tass news agency cited Putin spokesman Dmitry Peskov as saying Friday that the Kremlin had no faith in the UK inquiry and that UK investigators had been too quick to make accusations.
Case proved 'beyond reasonable doubt'
In his statement, however, Emmerson paid tribute to the efforts of the Metropolitan Police officers who probed Litvinenko's death.
"They may not in the end have been able to bring the murderers and their accomplices in Moscow before a British criminal court to face trial, but they have proved the case against them beyond reasonable doubt, just as surely as if they had been sitting in the dock at the Old Bailey," he said.
Perhaps the most crucial evidence, he said, was the discovery of polonium-210 contamination in the bathroom sink of the room in which Kovtun had been staying on the day he and Lugovoy met with Litvinenko for tea in the hotel bar a few floors below.
"It was not something that could possibly have occurred accidentally. The possibility of cross-contamination or secondary transfer can be completely ruled out," said Emmerson. "The inevitable conclusion is that the person who poured that solution down that sink was knowingly handling the murder weapon itself."
The investigation also uncovered polonium contamination on flights taken by the suspects and in other places where they had been.
Emmerson said the polonium "undoubtedly emanated from Russia and could not have been diverted for use as a murder weapon without the knowledge of the Russian officials and the approval of Mr. Putin personally."
The Metropolitan Police Service has not specifically accused Russia's President of being involved.
But lawyer Richard Horwell, representing the force, told the inquiry: "The Kremlin cannot exactly complain if the eyes of the world look to it for responsibility for Litvinenko's murder. And for all Litvinenko's targets, Putin was the one most frequently in his sights."
The police force has said Kovtun and Lugovoy should be tried for murder.
Horwell said the police investigation had "always had at its central core the science," ignoring the speculation and politics surrounding the case.
"It is the scientific evidence that condemns Lugovoy and Kovtun, and no matter how many state honors Putin may pin to Lugovoy's chest ... however meteoric Lugovoy's rise in politics has been and may become, however many conferences Kovtun may hold, or how many times Kovtun promises to 'blow apart' this inquiry, Lugovoy and Kovtun have no credible answer to the scientific evidence, and to the trail of polonium they left behind," he said.
Putin awarded Lugovoy -- a member of Russia's lower house of parliament, restaurateur and former host of a show called "Traitors" on Russian TV -- an order of merit in March.
Report due by end of year
The conclusion of the closed-door and public hearings in the case marks the end of a long journey for Marina Litvinenko.
The British government had initially rejected requests to hold a public inquiry, but the decision was reversed
after she challenged it in court.
The inquiry chairman, Sir Robert Owen, will share his findings with UK Home Secretary Theresa May before publishing his report before Christmas.
If it says the Russian state was involved in the death of a man who had become a British citizen, the UK government must decide on how that will impact its already poor relationship with the Kremlin.