Law enforcers are checking four versions of journalist Pavel Sherbet's murder, prosecutor Andriy Shevchenko from the Prosecutor-General's Office has said, according to 112 Ukraine TV.
"We are probing four versions: personal animosity towards the victim, professional journalist activities, possible destabilisation in Kyiv and in the country as such, and, fourth, they hit the wrong target because the car was usually used by Olena Prytula," Shevchenko said.
None of the versions is dominating, he added.
Minsk-born Russian and Ukrainian journalist was killed in a car explosion in central Kyiv on 20 July. The car belongs to Ukrayinska Pravda news website manager Olena Prytula who was not in the car. The FBI is working together with Ukrainian investigators.
A video was later leaked online which allegedly shows a woman putting something under Prytula's car while a man is on watch.
According to the crime detection chief of the National Police, Dmytro Holovin, police are looking for a young man who could see the criminals who booby-trapped Prytula's car.
"There is a witness who has not been identified yet, therefore we are calling on him to reach us through direct line or at 102. His statement would be important for us," he said.
In Holovin's words, the witness is a young man of under 180 cm. On the night of Sherement's murder he was walking along Ivan Frank Street and had a black backpack with two reflective strips on it.
Police learnt that the explosive was equivalent of 500 g of TNT. The FBI is helping Ukrainian law enforcers to identify its chemical composition, he added.
The FBI experts spent a week in Ukraine, examining the car and the crime scene, before going back home.