From Wikipedia

Umbrella Assassin

Georgi Ivanov Markov
(1 March 1929 – 11 September 1978)
was a Bulgarian dissident writer.

Markov originally worked as a novelist and playwright, but during 1969 he defected from Bulgaria, then a Stalinist state governed by President Todor Zhivkov. After relocating to the West, he worked as a broadcaster and journalist for the BBC World Service, the US-funded Radio Free Europe, and Germany's Deutsche Welle. He criticised the Bulgarian Stalinist regime many times by radio. It is speculated that, as a result of this, the Bulgarian government decided to dispose of him, and asked the KGB for help. He was killed on a London street after Bulgarian secret police fired a ricin-containing pellet into his leg.