London umbrella assassin is named Jack Hamilton, Sofia and Tom Walker THE IDENTITY of the secret agent who assassinated Georgi Markov, the Bulgarian dissident, with a poison pellet umbrella on Waterloo Bridge in London has finally been revealed. Leaked intelligence documents have named Francesco Giullino, a Dane of Italian origin who worked for the Bulgarian secret service, as the hitman who carried out the murder 26 years ago. The new evidence is likely to prompt fresh inquiries from Scotland Yard, which has kept an open file on the notorious cold war killing. Giullino, now 59, is named in Bulgarian secret...