Oren Dorell

USA TODAY

A former member of the Russian parliament is gunned down in broad daylight in the Ukrainian capital of Kiev. A longtime Russian ambassador to the United Nations drops dead at work. A Russian-backed commander in the breakaway Ukrainian province of Donetsk is blown up in an elevator. A Russian media executive is found dead in his Washington, D.C., hotel room.

What do they have in common? They are among 38 prominent Russians who are victims of unsolved murders or suspicious deaths since the beginning of 2014, according to a list compiled by USA TODAY and British journalist Sarah Hurst, who has done research in Russia.

The list contains 10 high-profile critics of Russian President Vladimir Putin, seven diplomats, six associates of Kremlin power brokers who had a falling out — often over corruption — and 13 military or political leaders involved in the conflict in eastern Ukraine, including commanders of Russian-backed separatist forces. Two are possibly connected to a dossier alleging connections between President Trump's campaign staff and Kremlin officials that was produced by a former British spy and shared with the FBI.

Twelve were shot, stabbed or beaten to death. Six were blown up. Ten died allegedly of natural causes. One died of mysterious head injuries, one reportedly slipped and hit his head in a public bath, one was hanged in his jail cell, and one died after drinking coffee. The cause of six deaths was reported as unknown.

Putin has long dealt with opponents harshly. Sen. Patrick Leahy, D-Vt., said in March that Putin “has murdered his political opponents and rules like an authoritarian dictator.”

Yet the list of fatalities — 36 men and two women — suggests that Putin’s alleged attacks on his critics and whistle-blowers are more extensive and lethal than previously known. It also raises new concerns about contacts Putin and his lieutenants had with Trump’s campaign staff.

Trump praised Putin in March 2016 as a "strong leader," and in 2015 said “I’d get along great with” the Russian leader. On Feb 6, Trump defended Putin when Bill O’Reilly, then of Fox News, called Putin a killer. "There are a lot of killers," Trump replied. "Do you think our country is so innocent?"

The FBI and Congress are currently investigating contacts between Kremlin officials and Trump's campaign advisers, as part of its investigation into Russia’s alleged interference in the 2016 presidential election.

Leahy made his comment about Putin at a congressional hearing that featured Vladimir Kara-Murza, a Russian political activist with personal experience of his government's efforts to silence outspoken critics.

"We’ve seen political opposition leaders and activists, whistle-blowers, anti-corruption campaigners and independent journalists lose their lives in one way or another," Kara-Murza told USA TODAY. "Sometimes these are suspicious suicides and plane crashes, really rare and horrible diseases. In many others they are straight murders."

Kara-Murza worked with former deputy prime minister and Putin opponent Boris Nemtsov before Nemtsov was gunned down in Moscow in 2015. Kara-Murza worked until recently with Russian anti-corruption lawyer and political candidate Alexei Navalny, who suffered eye injury Thursday after being attacked with a chemical following his release from jail for leading unsanctioned protests against the Putin government across Russia this spring.

“Sometimes there are near-misses," Kara-Murza testified in March before a Senate Appropriations subcommittee.

Kara-Murza said he was the victim of attempted poisonings twice: in May 2015 and this past February.

"Twice in the past two years I have experienced symptoms consistent with poisoning, both times in Moscow," he said in an interview. "Both times, symptoms came on suddenly and out of nowhere. Both times spending weeks in a coma on life support machines. Both times, doctors set my chance of survival at 5%, so I’m very fortunate to be here today. "

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Sen. Marco Rubio, R-Fla., noted at the hearing the dangers of winding up on the wrong side of politics in Russia. “In our system, if we make a bad decision, we might lose an election and have to work as a paid analyst on TV," he told Kara-Murza. "In your case, people die.”

Rubio and other senators had called on Secretary of State Rex Tillerson to meet with members of Russia’s political opposition during his April visit to Moscow, but Tillerson did not have time for a meeting, deputy spokesman Mark Toner said.

Most of the older diplomats on the list were probably victims of poor health, said Boris Zilberman, a Russia analyst at the Foundation for the Defense of Democracies.

“Knowing how diplomats live, going from one cocktail party to the next and not to the gym in between, it finally catches up to you,” Zilberman said.

That could apply to Vitaly Churkin, 64, the Russian ambassador to the U.N., who died on Feb. 20 in New York of an apparent heart attack. Others, like Petr Polshikov, 56, a chief adviser to the Latin America department at the Russian Foreign Ministry, found dead with a gunshot wound in his Moscow home on Dec. 20, require further investigation, Zilberman said.

“There’s almost a fever on the Russia story,” Zilberman said. “Some of it is substantial. It’s almost like there’s something nefarious behind every piece of news. Sometimes there is. ... They tend to clean up their messes this way.”

Many of the recent deaths raise suspicions because a string of Putin critics have died in obvious murders years earlier. They include:

• Nemtsov, who was shot to death while walking after dinner with his girlfriend in a security zone near the Kremlin. Two Chechen suspects, one a former bodyguard to Chechen leader Ramzan Kadyrov, are on trial, but the investigation did not reveal whether anyone ordered the hit.

• Sergei Magnitsky, a Russian tax lawyer who died in prison while investigating the alleged theft of $230 million by Russian government officials. No one was ever charged.

• Alexander Litvinenko, a Russian spy who defected, became a British citizen and was murdered in London in 2006 with radioactive polonium-210 while helping European authorities in a corruption investigation. The "state-sponsored murder" was an effort by the Russian government to send a chilling message to its critics, Peter Clarke, Scotland Yard's former deputy commissioner who led the investigation, told the British Daily Mail on April 17. Two Russian suspects were identified by British authorities, but Russia refused to extradite them, and no one was charged.

• Anna Politkovskaya, an investigative journalist who exposed Russian atrocities during the war in the restive Russian republic of Chechnya. She was gunned down in her Moscow apartment stairway in 2006. Former police officer Dmitry Pavliutchenkov was convicted of ordering surveillance of the journalist but denied killing her. He was sentenced in 2012 to 11 years in prison. Five alleged accomplices were later convicted, including two who were sentenced to life in prison. Pavliutchenkov's promise to identify who ordered the hit never resulted in further charges.

Two of the recent victims, Oleg Erovinkin and Alex Oronov, have been described by Russian analysts as possibly connected to a dossier written by a former British spy about Trump and his campaign staff’s alleged collusion with Russian efforts to interfere in the 2016 presidential election.

Erovinkin, 61, a general in the Russian spy agency and a close associate of a Putin confidant, was found dead in the back of his car on Dec. 26 in Moscow. The cause of death is unknown.

Oronov, 69, a Ukrainian-born businessman in New York, died under unknown circumstances around March 2, according to Andriy Artemenko, a member of Ukraine's parliament. Oronov had arranged a meeting between Trump’s lawyer, Michael Cohen; Trump business associate Felix Sater, and Artemenko in January about a peace plan for Ukraine that would benefit Russia. Artemenko alleged that Oronov died because of the peace-plan plot.

The list of recent deaths does not include Matthew Puncher, 46, a British polonium expert in the Litvinenko inquiry, reported to have stabbed himself to death in his home in Oxfordshire after returning from a trip to Russia last May.

Luke Harding chronicled a succession of suspected political murders in his 2016 book, A Very Expensive Poison; the Assassination of Alexander Litvinenko and Putin's War with the West. Former KGB officers and defectors described Soviet-era research into poisons used to kill enemies that continued in post-Soviet Russia, Harding wrote. Some substances are so rare and leave so little trace that death can be easily mistaken for a heart attack.

Journalist Hurst, who helped compile the list of deaths, said the recent uptick appears to be a sign of the growing political pressure on Putin and his cronies. “Putin is at the top of a criminal organization (and) there are all these people who have dirt on him,” she said. “It’s not surprising he’s willing to bump people off."

Kara-Murza, who is still recovering from the alleged poisoning, said he has "absolutely no doubt this was an attempt to kill me because of my political activities in the Russian opposition for the last several years, and more specifically because of my active involvement in the campaign in support of the Magnitsky Act," which calls for U.S. sanctions on Russian officials involved in human rights abuses and corruption.

He plans to push for similar laws in other Western countries, and to return to Russia to continue his activism when he is physically stronger.

Since many of the suspicious deaths are related to government corruption or those who exposed it, Kara-Murza urged Congress to block Russians who stole their nation’s wealth from investing in the United States.

"This is not only about money," he said in his Senate testimony. “Much more importantly it is about the message that the U.S. sends to Russia.”