Detective Chief Inspector Clive Driscoll was charged to review/reinvestigate the racist killing of Stephen Lawrence. The murder took place in 1993 and was reinvestigated by Driscoll in 2006.
One of the decisions he made (Decision 6 out of 326 decisions) proved to be the catalyst for solving this case. The murder not only embarrassed the Metropolitan Police was saw the force accused of institutionalised racism.
The case was eventually solved using contact trace technology.
Here is the full story.