When a Russian ex-con with a colorful past last year allegedly tried to kill a Kyiv-based Chechen man accused by Russia of plotting to kill President Vladimir Putin, Ukraine's interior minister saw a trail leading back to Moscow.

"We have established the motive, the substance, and the method of the execution of this crime, as well as a long trail leading to certain leaders of the Russian Federation," Arsen Avakov told reporters in June 2017.

Just over a year later, however, Ukraine has excluded from a formal indictment the claim that Russian leaders were involved in an alleged assassination attempt on Adam Osmayev, a native of Russia's Chechnya region whom Russian authorities say conspired to kill Putin.

Ukrainian prosecutors on June 5 presented their accusations in a Kyiv court against Osmayev's accused would-be killer, Russian national Artur Denisultanov, a fellow native of Chechnya and a veteran of Russia's 1990s gang wars known by the nickname Dingo.

Prosecutors now say that Denisultanov, who has used an array of other last names, was acting out of "personal animus" when he allegedly tried to shoot Osmayev and his wife, Amina Okuyeva, at a meeting in Kyiv in June 2017.

​Okuyeva was shot and killed in a separate incident four months later, when she and her husband were ambushed on the outskirts of the Ukrainian capital. Osmayev, who was injured in the attack, has accused Russia of ordering the fatal shooting.

Ukrainian Prosecutor-General Yuriy Lutsenko said last week that there had been no significant progress in the investigation of Okuyeva's killing.

Both Denisultanov's biography and the circumstances of his alleged crime feature underworld misadventures that would not be out of place in a novel by the renowned U.S. crime writer Elmore Leonard.

In the early 1990s, Denisultanov went on a popular Russian television program to warn business rivals that "things will end very badly" for them if a commercial dispute were not resolved. In 2001, he co-authored a potboiler about a pistol-wielding Chechen named Artur.

Denisultanov turned up in Austria in 2009 to seek political asylum, claiming Chechnya's Kremlin-backed leader, Ramzan Kadyrov, had a hit list of 300 enemies who "have to die." After his asylum application was rejected, Austrian police said later that Denisultanov was believed to be dead.

But he was very much alive, and imprisoned in Russia on a theft conviction in 2011. Denisultanov then surfaced in Ukraine last year posing as a French journalist trying to arrange a meeting with Osmayev and Okuyeva, both veterans of combat against Russia-backed separatists in eastern Ukraine.

Ukrainian authorities say the couple were in the car with Denisultanov -- who had a Ukrainian passport under the name Oleksandr Dakar -- when he pulled out a handgun and shot Osmayev twice.

Okuyeva then shot Denisultanov twice with her own gun, injuring but not killing him, authorities said.

Reading the indictment against Denisultanov in Kyiv's Podilsky District Court on June 5, prosecutor Dmytro Velychko said the alleged attack was motivated by the open criticism that Osmayev and Okuyeva voiced about Russia's backing of separatists fighting Kyiv's forces in eastern Ukraine -- a war that has killed more than 10,300 since April 2014.

"At the moment, according to the indictment, we believe it was [motivated by] the personal animus of the individual in question," Velychko said following the hearing.

Osmayev and Okuyeva had previously said they believed Kadyrov was behind the alleged attempt on their lives, and that it had been aligned with the Kremlin, according to Current Time, a Russian-language TV network run by RFE/RL in cooperation with VOA.

Asked why the indictment did not include any mention of a link to Russian leaders, Velychko said that "everything in the indictment that was read by me is confirmed by evidence in the criminal case."

"Other statements and reports, including by politicians in the early stages of the investigation, have not, as you heard, been confirmed as of today," the Ukrainian news site UNIAN cited Velychko as saying.

Denisultanov has denied that he tried to kill Osmayev and Okuyeva and said that he was a victim of the couple. He told RFE/RL’s Kavkaz Realii in January that he indeed posed as a French journalist gathering information about Chechen emigres, and claimed the couple attacked him at their final meeting. He claimed that Okuyeva shot him following a tussle over Osmayev's handgun.

Ukraine has been rocked by a string of high-profile killings that remain unsolved, including the July 2016 car bombing in central Kyiv that killed Pavel Sheremet, a Belarusian-born Russian journalist.

Ukrainian authorities last week faked the death of Kyiv-based Russian journalist Arkady Babchenko, an operation that involved lies by officials to the public and the media before they revealed a day later that Babchenko was alive.

Ukraine claims that the operation helped prevent a Russian assassination plot, an assertion rejected by Moscow.

