Hugh Orde’s appointment as Northern Ireland’s new police chief puts him in charge of many officers he was actively investigating.
He has been running Metropolitan Police Commissioner John Stevens’s latest probe into allegations that security forces colluded with loyalist terrorists in the murder of Belfast lawyer Pat Finucane.
The role has allowed him to scrutinise in detail the most controversial aspects of policing in Northern Ireland and accusations that Special Branch has been operating as a ‘‘force within a force’’.
The Stevens III report is expected to contain heavy criticism of how the old RUC handled inquiries into the 1989 killing.
It is due to be published in a month’s time - around the same time Mr Orde, 43, takes charge of the reformed Police Service of Northern Ireland.
But the sensitivities of investigating Special Branch are unlikely to phase a man who has enjoyed an illustrious career in the Met.
He joined the force 25 years ago in his late teens before rising to the rank of Deputy Assistant Commissioner.
With his heavy involvement in the Finucane investigation, there were ripples of surprise when it emerged Mr Orde had entered the race to become Ronnie Flanagan’s successor.
He has already admitted it is unlikely the person who killed the solicitor will ever be caught.
Nevertheless, he must now contend with officers whose loyalty to Special Branch could be at odds with criticisms expected to be levelled at the unit in the Stevens document.
A keen runner who has completed five London Marathons, his stamina is now set to be tested once again in the cauldron of Northern Ireland policing.