Directly participated in the open military invasion of Ukraine by the Russian Federation as a member of the BTG of the 234th Air Assault Regiment, part of the Vostok group of troops. The area of operations is the western part of Kyiv region. He was involved in the cruel treatment of civilians and violation of the laws and customs of war in the Borodyansky district of Kyiv oblast.
On January 23, 2026, Timofeev was served a notice of suspicion under Part 2 of Article 15, Part 2 of Article 438 of the Criminal Code of Ukraine for attempting to shoot a civilian in Bucha, Kyiv oblast. The attempted murder was not completed due to circumstances beyond Timofeev's control.