De Silva was
called to the bar from the
Middle Temple in 1964, and was appointed a
Queen's Counsel in 1984. In October 2011, with the approval of
Prime Minister David Cameron, de Silva was appointed to head a Review into collusion by the security services and other agencies of the state into the 1989 murder of the high-profile Belfast lawyer
Pat Finucane. The report was published on 12 December 2012, and acknowledged "a willful and abject failure by successive Governments"; however, Finucane's family called the de Silva report a "sham". In 2019 the Supreme Court ruled that the official investigation into the Finucane murder was ineffective and failed to meet the required human rights standards. On 23 July 2010, he was appointed by the United Nations Human Rights Council to investigate Israel's
interception of a Gaza-bound flotilla in international waters that led to 9 deaths. In 2014, he was Chairman of an Inquiry into torture and executions of detainees in Syria. The Report produced went before the Geneva 11 Peace Talks into the civil war in Syria. On 10 January 2016, a Senior Army Commander complained about a "witch hunt" against British soldiers who were Iraq War veterans by pursuing frivolous legal claims. De Silva agreed with the Army Chief by saying, "Up to now nobody has got these ambulance-chasing lawyers by the scruff of the neck." ==Personal life and death==