So, who to believe? Gerry 'I-was-never-in-the-IRA' Adams, or the Stack family?
It's not a particularly tough call, this one.
We are being asked to choose between Austin Stack, son of murdered prison officer Brian Stack, and one Gerard Adams, president of Sinn Féin.
The Stack family have campaigned for 30 years for some form of recognition for their husband and father, who was a senior prison officer in Portlaoise Prison at a particularly fraught time in our history. It has been a very hard and lonely road for them, and for a long time their story did not fit with contemporary politics in a changing Ireland amid a quest for some resolution in the North.