Before the murder, Nemtsov was monitored by an agent of the "shock squad" of the FSB - media

Before the assassination, Boris Nemtsov was monitored by an FSB officer associated with a secret assassination squad operating under the structure. This is evidenced by the results joint journalistic investigation The Insider, Bellingcat and BBC.

The data showed that Nemtsov was under surveillance for about a year, the agent “accompanied” him on at least 13 trips.

Journalists studied the data on booking tickets for trains and flights and found that a certain Valery Sukharev was assigned to Boris Nemtsov. The last time surveillance was carried out on February 17, 2015, 10 days before the murder of an opposition leader.

“All bookings for planes and trains are entered into the FSB database called Magistral. But this database not only captures the movements of people that Russian agents may wish to track, it can also be used to reveal the movements of the agents themselves, such as Mr. Sukharev. Such information often ends up on the black market and ends up in the hands of journalists,” the article explains.

Some of the input to this investigation was acquired by Bellingcat through brokers within Russia. They, in turn, received them from corrupt officials with access to the Magistral. The BBC also used open source data.

Nemtsov reportedly made most of his travels from Moscow, where he lived, to Yaroslavl, 272 kilometers (169 miles) northeast of the capital. Sukharev often arrived at the oppositionist’s destination minutes or hours ahead of him.

In the summer of 2014, Boris Nemtsov traveled to Siberia. He booked a ticket online on July 2 just after midnight. Exactly 10 minutes later, Sukharev bought a ticket with a similar destination and arrived in Novosibirsk on the same day as Nemtsov, according to the investigation.

“It is not unusual in Russia for the security services to spy on prominent opposition leaders. But Mr. Sukharev was not just a low-ranking FSB officer doing routine work. Bellingcat, in a previous investigation, linked him to two assassination attempts, both of which targeted prominent critics of Mr. Putin.

One of these critics is Alexei Navalny. Valery Sukharev was not part of the group that physically followed the oppositionist. But phone logs show that in the months immediately prior to Navalny’s poisoning, Sukharev exchanged 145 phone calls or text messages with at least four members of this physical surveillance team, as well as with a higher-ranking FSB officer.