During his tenure, the failure of the prosecutions of Paul Burrell and the killers of Damilola Taylor damaged the Service's reputation, and the CPS was described as "institutionally racist" by him and two reports.

When the Human Rights Act 1998 was passed (most of which came into force in 2000), Calvert-Smith was the first DPP to have to deal with the impact it was expected to have on criminal trials.

In a letter to Parliament, he wrote: "the best approach is for the jury to focus on weighing the evidence tending to demonstrate intent to supply ... as opposed to this issue being determined with reference to an arbitrary amount".

Towards the end of his term, he piloted a new system in which CPS lawyers, instead of police officers, would make decisions about charging suspects, resulting in a 15 percent increase in convictions.

At a press conference, Calvert-Smith said that "willingness to change at the top is not translating into action lower down, particularly in middle-management where you find the ice in the heart of the Police Service.