Kryukov turned to police chief, General Bogdan Romanuk, at the Lviv police headquarters on 7 April 1996, for advice. General Romanuk, ordered Kryukov to form a task force immediately and search Onoprienko’s apartment. On 16 April 1996, Kryukov and his task force of more than 20 detectives and patrolmen drove in unmarked police cars to Onoprienko’s residence. They surrounded the building in Ivana Khristitelya Street and blocked the entrances.

Police knocked on the door and an unwitting Onoprienko opened it, thinking it was his girlfriend and her children returning from church. Police handcuffed him and began a search of the apartment. In the living room, they found a stereo of the same make as one reported missing from the home of the family murdered on 22 March 1996 in Busk. It was later confirmed through a serial number match, to be the very one stolen from the murdered family’s home.

The task force also discovered a pistol in Onoprienko’s possession that was later matched to a murder scene in Odessa. Onoprienko was arrested and taken into custody whilst investigators conducted a more thorough search of the apartment. They found in excess of 120 items linked to various unsolved murder cases, including a 12-gauge shotgun. In addition, Onoprienko’s girlfriend was found wearing a ring that he had stolen from one of his victims.

Onoprienko waived his right to an attorney and was initially disinterested in talking to the police, saying he would only speak to a General. Kryukov was forced to call in lead investigator, Bogdan Teslya, to interrogate Onoprienko.

Whilst in custody, Onoprienko confessed first to stealing the 12-guage shotgun found at the time of his arrest, then to using it in a murder in 1989. He then said he had used it in eight murders between 1989 and 1995. He also told investigators of his friend and accomplice, Serhiy Rogozin. Onoprienko denied the other charges but admitted to a six-year killing spree, involving 52 victims. He explained to police that he was told to commit these murders, by voices he heard in his head.