Events at the Regency Hotel in Dublin in 2016 are the most notorious – to date – in an unprecedented cycle of death and suffering. For the family of David Byrne, who was shot dead that day, the collapse of Patrick Hutch’s trial at the Special Criminal Court will bring more pain. The family of Det Supt Colm Fox, the lead investigating garda on the case, who died in February 2018, has also been through an awful ordeal.

Notwithstanding the sensitivities involved, however, the public should be told why the trial collapsed. It is not sufficient to accept a decision by the Director of Public Prosecutions that charges should be dropped and allow the reasoning to go unexamined. Transparency is essential if the public is to be reassured that all appropriate lessons have been learned and issues addressed.