Andrew Shannon, 49, of Willians Way, Ongar, Dublin, had pleaded not guilty to damaging the painting, Argenteuil Basin with a Single Sail Boat (1874), on June 29, 2012.
A jury of seven women and five men returned a verdict of guilty on that charge yesterday afternoon following almost one-and-a-half hours of deliberation on day eight of the trial.
The court heard Shannon has 48 convictions in this and other jurisdictions, some of which are for burglary and theft offences involving antiques. In November 2011, he was sentenced in Wicklow Circuit Court for handling stolen property involving maps dating from 1651 with a value of €6,000.
The restored Monet painting is back on display in the National Gallery.
Judge Martin Nolan imposed a sentence of six years and suspended the final 15 months on strict conditions, including that Shannon not enter into a public painting gallery or any other institution or building where paintings are publicly displayed. The maximum sentence for this offence is 10 years.
Judge Nolan had earlier directed the jury to find Shannon not guilty of damaging two paintings at the Shelbourne hotel on January 8, 2014.
Garda Sergeant Conor Ó Braonain told Kerida Naidoo, prosecuting, that Shannon had entered the gallery just before 11am and had gone to where the painting was on display. He left and returned a short time later and appeared to fall, striking the painting.
Shannon said he had been dizzy and had fallen forward. He had spoken to a number of people, including two tourists from New Zealand and security staff, at the scene telling them he had a heart condition.
Sgt Ó Braonain agreed with Mr Bowman that Shannon suffers from significant heart difficulties.
Mr Bowman said Shannon had been in custody since the date of offence except for a six-week period.
Judge Nolan said he was taking into account Shannon’s age and medical condition in sentencing.
He said all the time Shannon had spent in custody should be taken into account.