A micro-pellet containing ricin was fired into his leg via an umbrella wielded by someone with probable links to the Bulgarian secret police .
Markov was a Bulgarian dissident writer assassinated on 11 September 1978 , in London .
A micro-pellet containing ricin was fired into Markov 's leg via an umbrella wielded by someone with probable links to Bulgarian Bulgarian secret police .
Markov was a Bulgarian dissident writer assassinated on 11 September 1978 , in London .