|Full name||Ilya Tretyakov|
|Cause of death||Hanging|
|Partner(s)||Nina Rodionova (girlfriend)|
|Appears in||Criminal Case|
|First appeared||Case #16: Fast Track to Murder (s3)|
Ilya was a diamond magnate who was dating figure skater Nina Rodionova before his death. Ilya had graying brown hair, gray eyes, and a beard. At the time of his death, he wore a black suit accompanied with a brown tie embedded with diamonds.
Ilya was found hanging by his tie on one of the train cars. According to Angela, he received a blow to the head which stunned him. She confirmed that he was strangled to death by being hanged with his own tie. She managed to find traces of tobacco on the victim's tie, but the Ilya's lungs were clear of smoke. This meant that the killer smoked cigarettes.
Killer and motives
The killer turned out to be a ticket inspector named Nikita Rukhin.
As Carmen laid out the pieces of evidence she found against Nikita, the latter accidentally spilled that he should not have turned his back against Ilya, prompting him to confess to the murder. Nikita revealed his hatred of the victim, saying that diamonds should belong to the people rather than to oligarchs. He had also returned the diamonds, which he took from Ilya, to communist hands in China. Ilya found out and confronted Nikita, prompting the latter to knock him out and hang him. Nikita then stopped the train because it was his job to report railway incidents, and also to hide the evidence in the ice cave.
Rather than taking Nikita to the courthouse, Carmen video-called Judge Adaku and had the trial held by phone on the train. Nikita pleaded guilty for the murder, though he claimed his intentions were pure. The judge questioned him about how his actions were pure if blood was shed, and Nikita explained about how he was helping the Communist cause. Nikita also told the judge that in 1918, Lenin had told his citizens to hang “rich bloodsuckers”, inspiring the ticket inspector to do so when Ilya confronted him. The judge explained that his ideological zeal did not change the fact that he killed a man and was forced to do a video-linked trial, and so he sentenced Nikita to 25 years in prison.