Could the next Garda commissioner be a member of the PSNI? That intriguing possibility is opened up by the fact that most of our assistant chief constables are barred from applying for the top PSNI job, but the Dublin position is likely to invite external applicants.
Applicants for the post of Chief Constable must have served two years at assistant chief constable (ACC) level in an outside force.
The criteria for Garda commissioner have yet to be published, but the Irish government is reportedly determined to advertise it externally and Enda Kenny, the taoiseach, has already publicly invited applications.
Commissioner Callinan retired amid controversy and was visited by a senior civil servant the night before he quit. An early blow to his leadership came when the Smithwick tribunal found that individual gardai had colluded in the murder of two senior RUC officers in 1989, something which counsel for Mr Callinan had argued against at the tribunal.
Smithwick also found that, although there was no institutional collusion, wrongdoing was sometimes hushed up due to 'some misguided sense of loyalty' within the Garda and a desire to protect the force's reputation.
Then whistleblowers accused gardai of setting aside penalty points for well-connected motorists. Mr Callinan described that accusation as "disgusting", but an independent report found it to be credible.
Most recently, it emerged that gardai had, illegally it appears, recorded phone calls made from Garda stations and kept records of them. There is now an inquiry into that.
All these scandals, allegations of cover-up and unanswered questions, could boost the chances of an external candidate, with no history in the force, no potential baggage and nothing to hide.
It could be that they will go for a civilian – someone from another state agency, for instance. But there are few police officers from external forces who would know the Garda set-up as well as the top tier of ACCs at the PSNI.
Looking down the list, Alastair Finlay is said to be planning to retire this year, while George Hamilton is the only ACC eligible to apply for the post of Chief Constable and is, therefore, favourite to succeed Matt Baggott.
Drew Harris (above), in particular, has dealt extensively with the Garda and gave evidence at Smithwick, which Mr Callinan's lawyers rejected at the time, but which the tribunal accepted. Will Kerr could be another possible candidate once the post is advertised.