A serial killer known as “the werewolf” killed as many as 81 women, according to police. The new death toll would make Popkov Russia’s worst serial killer.

Former Siberian policeman Mikhail Popkov, who is serving a life sentence for murdering 22 women, has confessed to 59 new killings, according to the Russian Investigative Committee (RIC). The RIC, Russia’s equivalent of the FBI, says Popkov told them he had killed the women during a rampage which ran from 1994 to 2000. The crimes went unsolved for many years because the police failed to conduct DNA tests on their own officers.

The women, aged between 17 and 38, were raped before being killed with axes, knives or screwdrivers. Popkov wore his police uniform as he lured drunken victims into his police car, offering them late night rides back home from bars. The married father-of-one would then drive them to deserted areas and brutally attack them, dumping their naked bodies in the woods.