An explosion was reported in a courthouse in Kyiv's Shevchenkivskyi district, the National Police wrote on July 5.
The Prosecutor General's Office reported that two Rapid Operational Response Unit officers were injured as a result of the explosion in the courthouse.
Interior Minister Ihor Klymenko confirmed during a press conference after the incident that the defendant, Ihor Humeniuk, triggered the explosion.
Humeniuk was accused of killing four members of the National Guard in 2015.
According to Klymenko, Humeniuk threw an explosive device at the guards after his hearing and attempted to leave the court. The guards fired a warning shot into the air and Humeniuk barricaded himself in a restroom.
The Rapid Operational Response Unit attempted to get Humeniuk to stand down but he refused to cooperate and threw another explosive device at the special police officers.
Humeniuk died in the explosion. The two special police officers do not have serious injuries, Klymenko added.
In 2015, during a protest in front of the parliament building in Kyiv against constitutional changes that would grant Russian-occupied regions autonomy within Ukraine, Humeniuk detonated a grenade that killed four National Guard members and injured over 100 people.
Oleksandr Svyrydovskyi, Humeniuk's lawyer, expressed his reservations to Ukrainska Pravda about officials' account of events.
"I have doubts that he blew himself up. He could have been shot by Rapid Operational Response Unit officers during the assault. It's important to investigate the forensic examination here," Svyrydovskyi said.
According to Svyrydovskyi, the end of August would have marked eight years since Humeniuk had been held in a pre-trial detention center without a sentence, and "it was clear that he was morally broken."
Humeniuk also repeatedly asked to be sent to the front and defend Ukraine against the full-scale Russian invasion due to his past military experience, Svyrydovskyi added.