Roman Nevikov
Occupation Russian mobster
Played By Garret Dillahunt
Status Killed in "Episode 2-21: One"

Roman Nevikov (played by Garret Dillahunt) is a ruthless Russian mobster and human trafficker based in Los Angeles. Supposedly, Nevikov was born in prison, and exhibits extreme sociopathic tendencies. Cool, calm, and extremely confident, Nevikov always seems to know specific and private details about those he interacts with (particularly Charlie Crews and Dani Reese). Those who work for him fear him as being untouchable. This is proven when Nevikov, having murdered one of his prostitutes and been subsequently arrested by Crews and Reese, is released without charge when it is revealed that he is a protected federal informant.

While in custody, Nevikov provided information to Crews that led him to shift the focus of his personal investigation towards the Bank of Los Angeles Shootout. In season 2, however, it is revealed the agent who delivered this news (FBI Special Agent Paul Bodner) was really corrupt and working for Nevikov. Nevikov brought a team of builders consisting of two builders/mob enforcers and an engineering genius, over from Moscow to the United States illegally, and then had them monitor the site of the future new federal building in Los Angeles, copy details of the building's security system, and then installed it in Nevikov's club (under the guise of unknown renovation work), as well as underground vaults underneath the basement. Once the work was completed, Nevikov couldn't risk his secrets being exposed as the builders knew too much, Nevikov executed all three. Crews and Reese investigated, and eventually approached Nevikov about the killings. Nevikov denied any knowledge, but because they "asked nicely" (appealed to his ego), he agreed to ask around.

Nevikov noticed the detectives continuing investigations on him, and subtly threatened Rachel Seybolt's life if Crews investigated too deeply. The LAPD launched a search of Nevikov's club, hiding it from federal attention, but found nothing, and Bodner claimed jurisdiction over the case when it was suspected the engineer was involved in terrorism. Crews figured out by reading Russian history what Nevikov had done, as well as suspecting the engineer; Pavel, had left a "trapdoor" in Nevikov's security system for them to find.

As such, Crews, Reese and a SWAT team stormed Nevikov's club, with Nevikov calmly waiting for them and gave himself up. Initially he remained calm and confident they wouldn't find anything yet again, but Crews used the personal laptop built by Pavel for Nevikov to unlock the "trapdoor" in the security system (a video made and narrated by Pavel shortly before his death) explaining what transpired as well as revealing what he found was going on in the underground vaults beneath the club's basement (human trafficking). The people were released and Nevikov was believed to have been brought to justice.

It was later revealed that Nevikov was an "investment" for The Group who was abandoned in favor of Crews to take charge of their money laundering operation. Spurned by this betrayal, Nevikov hunted down and killed Jack Reese, and attempted to do the same with Mickey Rayborn, failing when Rayborn went into hiding. Needing a way to find him, Nevikov arranged with his friends in the FBI to have Dani captured, and then tried to tie up loose ends by having the same agents killed. Crews realized Nevikov was still at large when, going to the maximum security prison to see him, he instead found another prisoner paid to impersonate Nevikov and serve his sentence in his place. Nevikov then contacted Crews with a straight deal: Reese for Rayborn. Crews, instead, offered up himself as he had intimate knowledge of Rayborn's financial details, which Nevikov could use to take over the laundering operation. While in transport, Crews used a technique he learned in prison to crush Nevikov's windpipe, thereby killing him. Nevikov's bodyguards, really working for him out of fear for their families, let Crews go when he explains to them that whatever Nevikov had on them died with him.