The story that Father Grogan tells Michael and Christine about finding Michelangelo da Caravaggio's "The Taking of Christ" is true. The painting was found by accident when it was sent for cleaning. It can now be see in the National Gallery of Ireland as stated.
Kevin Spacey would later recommend Colin Farrell to director Joel Schumacher, with whom he had made A Time to Kill (1996). Schumacher would give Farrell his first Hollywood break in the critically acclaimed Tigerland (2000).
Kevin Spacey hosted a Q&A at the Irish Film Institute in Dublin, while he was filming "Ordinary Decent Criminal". He was interviewed by the late Irish Times film critic Michael Dwyer, and regaled the delighted audience with stories and spot on impersonations of Brando, Pacino, O'Toole and Jack Lemmon amongst others. There was however a palpable hush in the room when he finally unveiled the accent he was utilising for the movie, as it seemed very "Stage Irish".
As Michael is running out of the museum, stealing the painting of Judas kissing Jesus, the exhibition sign he passes reads "The Taking of Christ".