A professional assassin, he was assigned by Soviet dictator
Joseph Stalin to kill exiled Communist leader and theoretician
Lev Trotskiy, who was living in Mexico. Mercader successfully accomplished that assignment on
August 20, 1940, in Trotsky's home in the Coyoacán district of Mexico City. He
served a 20-year sentence and was released in 1960. After his
release he spent his final years between Russia and Cuba.