Police investigator Yevgeniya Shishkina was shot dead outside her home near Moscow in October 2018. She had been working for the interior ministry investigating drug trafficking and fraud.
In March 2019, police arrested two St Petersburg residents in connection with the murder. 19-year-old medical student Abdulaziz Abdulazizov and a 17-year-old schoolboy, who cannot be named for legal reasons, are due to be prosecuted later this year.
Legal documents, which BBC Russian claims to have seen, allege that the suspects were paid one million rubles (£11,655) to carry out the assassination. Police reports state that the killing was ordered by the owner of a drug-dealing site on an illegal online trading platform, Hydra, which resides on the dark web.
The unnamed person who allegedly ordered the hit goes by the pseudonym, Miguel Morales, according to the legal documents, and was being investigated by Lt Col Shishkina. She is said to have received numerous threats in the months leading up to her murder.
In August 2018, the accused 17-year-old allegedly posted on Hydra seeking employment opportunities. Police state that he then received a message in September asking for a private messaging address, at which point discussions regarding the contract killing took place.
The legal documents assert that the 17-year-old then kept 400,000 rubles and paid Abdulazizov to carry out the hit.
Police say that Abdulazizov travelled to Lt Col Shishkina by taxi, which he had ordered via mobile phone app. He apparently confessed to approaching Lt Col Shishkina outside her home at 6.30am before shooting her twice at close range from behind.
Police say they were able to track down Abdulazizov by examining all the journeys made via taxi apps in the area that morning.