Killing of Valentina Ulanova and Sergei Potanin (Tamara Samsonova case)

Tamara Mitrofanovna Samsonova (born 25 April 1947, in Uzhur, now part of Krasnoyarsk Krai) studied at the Maurice Thorez Moscow State Pedagogical Institute of Foreign Languages before moving to Leningrad, where she married Alexei Samsonov. The couple settled in 1971 in a newly built apartment on Dimitrov Street in St. Petersburg. Samsonova later worked for the Intourist travel agency, including at the Grand Hotel Europe, accumulating 16 years of work experience by the time of her retirement.

In 2000, Samsonova's husband disappeared. She reported this to police at the time, but the search produced no results. Fifteen years later, in April 2015, she gave a formal statement about the disappearance to the investigative unit of the Frunzensky District in St. Petersburg.

After her husband's disappearance, Samsonova began renting out a room in her apartment. On 6 September 2003, during a quarrel, she killed her tenant, 44-year-old Sergei Potanin, dismembering his body and disposing of it outdoors on Dimitrov Street. A second male victim, a 32-year-old resident of Norilsk, is also referenced in connection with this period.

In March 2015, a mutual friend asked 79-year-old Valentina Nikolaevna Ulanova, who also lived on Dimitrov Street, to temporarily shelter Samsonova while her apartment was being renovated. Samsonova stayed in Ulanova's home for several months, helping with housework, but the relationship deteriorated. When Ulanova asked her to leave, Samsonova refused. She then traveled to Pushkin and persuaded a pharmacist to sell her the prescription drug phenazepam, which she mixed into an Olivier salad — a dish Ulanova favored — and gave to her.

On the night of 23 July 2015, Samsonova found Ulanova's body on the kitchen floor. She dismembered the body using two knives and a saw, bagging the remains and making several trips to remove them from the apartment. Ulanova's dismembered body, wrapped in a bathroom curtain, was discovered on the evening of 26 July near a pond by house number 10 on Dimitrov Street; the package went unnoticed for several days until a resident examined its contents. Ulanova's identity was confirmed on 27 July after police surveyed neighboring apartment residents. When officers arrived at Ulanova's apartment, Samsonova answered the door; police found bloodstains in the bathroom and the torn fastening from the missing curtain, leading to her arrest.

On 29 July 2015, Samsonova appeared before the Frunze District Court of St. Petersburg. A forensic psychiatric examination completed on 26 November 2015 found she posed a danger to herself and society, and she was ordered held in a specialized institution pending investigation. In December 2015, she was transferred for compulsory psychiatric treatment to a specialized hospital in Kazan. Investigators have linked her to a total of 14 killings. A diary recovered by police contained entries describing some of the killings, including one describing the killing and dismemberment of a tenant referred to as "Volodya."