When she refused, he strangled her in a fit of rage and then fled, leaving a note on the corpse: Goodbye my love, I'll be with you soon!
On June 29 Sergeev broke into a factory on Dzerzhinsky Street in Zaporizhzhia, stole several ushankas (Russian fur hats with ear flaps) and gold ornaments, and killed a cleaning woman, Natalia Yurchenko.
On July 9, 1987, he returned to Zaporizhzhia, bursting into an apartment on Paramanov Street and inflicting serious wounds on nine-year-old Lena Novikova.
On July 12, he attacked two teenagers with a knife while they were bathing in a pond near a village in the Prymorsk Raion, but both of them survived.
To catch the killer, servicemen, troops, fire brigade workers, aviation crews and volunteers were organized in the 587 settlements of Zaporizhzhia Oblast.
On July 17, 1987, Sergeev was found near the state-run farm Mokryanka, and was finally detained near the village of Krinichka.
He attempted to resist arrest by throwing a knife at police, but an officer shot him in the leg and he was taken into custody.