The killer, who attempted unsuccessfully last year to murder Anti-Terrorist Operations veterans Adam Osmayev and Amina Okuyeva, refuses to testify. The assassins who successfully murdered Amina Okuyeva remain at large, advisor to Ukraine's Interior Minister and Verkhovna Rada of Ukraine deputy (People's' Front Party faction) Anton Gerashchenko has said.

"Last year there were two attempts to kill Amina and Adam, who escaped the first. That assassin is in pretrial custody and the case will go to court this year. He will receive, I believe, a life prison sentence. The suspect refuses to give testimony," Gerashchenko told reporters in Kyiv on Tuesday.

Gerashchenko said the primary version of the second successful assassination of Okuyeva in October is as follows: revenge by Russian terrorist saboteurs with the assistance of Russian special forces.

Osmayev was wounded in first attack in June 2017 and wounded on October 30, 2017 attack that killed Okuyeva.