Serhiy Fedorovych Tkach was born at Kiselyovsk in Siberia on September 12, 1952 and served in the Soviet militia as a criminal investigator and forensic specialist before being dismissed for falsifying evidence.
That training is the whole of the case. He knew what investigators looked for and he removed it, washing the bodies and the scenes and staging the deaths as accidents or drownings.
Between 1980 and 2005 he killed at least twenty-nine, and by his own account around a hundred, girls and young women aged between eight and eighteen, across Crimea, Zaporizhzhia, Dnipropetrovsk and Kharkiv. Ukrainian reporting called him the Pologovsky Maniac, after the district.
He suffocated or strangled them, raped them before and after death, and left them in water, in fields and beside railway lines.
Because the scenes were clean and the deaths looked accidental, the Soviet and then Ukrainian militia closed the cases by other means.
At least nine men were convicted of murders Tkach committed. One killed himself in custody. Another served fifteen years. Several were beaten into confessions.
He was caught in August 2005 in Pavlohrad after attending the funeral of a girl he had killed, where he was noticed and detained.
He was convicted on December 23, 2008 of thirty-seven murders and sentenced to life. He died in prison in Zhytomyr on November 4, 2018.
Thirty-seven convictions against nine wrongful ones. This entry belongs beside the archive's other clearance-rate cases: the deaths were not missed because they were hidden well, but because a system measured on cases closed will close them on whoever is available.