The man responsible for the investigation into collusion between loyalist paramilitaries and the security forces in the North performs his last duties today as a police officer.
Sir John Stevens, now Metropolitan Police Commissioner, conducted three investigations into RUC collusion with loyalist groups that led to 43 convictions with sentences totalling over 800 years.
Among the cases he investigated was the killing of lawyer Pat Finucane by the UVF. His murder was one of many incidents that allegedly involved assistance from the British Army's Force Research Unit, which handled paramilitary informants.
A year after beginning his first investigation, a fire, probably started deliberately, at his offices in Carrickfergus destroyed many important files.
Today he takes responsibility for last official public engagements today after 43 years as police officer. He will be succeeded by his deputy Sir Ian Blair.
He is attending the force's training centre in Hendon, north London, where one of the force's three new communications buildings will be named after him.