Gardai have confirmed that a man has been arrested after writing a derogatory comment in a book of condolence for Garda Colm Horkan.
It is the incident which occurred in Blanchardstown on Friday, came to light after the man allegedly shared an image of the defaced book with an emoji.
Gardai say the 23-year-old man was arrested in connection with the incident and taken to Blanchardstown Garda Station for questioning.
It is understood that such an offence carries a penalty of €1,000 fine and a 12 month prison sentence.
The news comes after Detective Horkan was shot dead whilst responding to an incident in Castlerea, Co Roscommon last Wednesday.