Military Collegium of the Supreme Court of the USSR
Bron was arrested on 25 October 1937. He was falsely accused of being a member of an anti-Soviet terrorist organization; of preparing, together with Tomsky, a terrorist act against Stalin; and of being an agent of British intelligence. After five months in Lubyanka prison, on 21 April 1938 he was tried in a closed session by the "troika" (the three-member Military Collegium of the Supreme Court of the USSR). He was sentenced to death and was executed the same day.