HE WAS rumoured to keep an old four-poster bed in his council flat such was his appreciation of finer things in life. But new footage shows the supposed art lover Andrew Shannon strolling around the National Gallery before deliberately slamming his fist through the canvas of a €10m Monet painting.

The previously unseen footage, from the gallery's CCTV system shows how the 49-year-old strolled through the gallery rooms carrying a yellow plastic bag with a tin of Nitromores paintstripper in it.

He paused in front of Carravagio's Taking of Christ, but otherwise he barely stopped to admire the art work. Seconds later he strolled into the room in which Argenteuil Basin with a Single Sail Boat by Claude Monet was hanging.

He did a casual lap of the room. As he approached the Monet again, he leaned in over the wire perimeter, raised his forearm above his head and smashed it down on the canvas. A millisecond later, he slumped forward against the painting, as though he had fallen.

He immediately regained his composure and attempted to walk away, but a New Zealand couple who witnessed the attack surrounded him. When a security guard appeared, Shannon made for a bench, where he lay down feigning illness.

Last Thursday, Shannon was convicted of criminal damage to the Monet painting and was sentenced to six years in jail for what the judge called a "peculiar" and "abnormal" crime.

His trial heard that he told a paramedic who treated him at the scene that he had a heart condition - and later he had a quadruple bypass while in custody. But the paramedic reported that his vital signs were normal.

The New Zealand tourists also challenged his account. Michael Kelly Williams said he saw a man with a clenched fist put it straight into the Monet. He grabbed the man and moved him into the middle of the room to get him away from the paintings. His wife, Toni Ashton, said she saw a fist go through the painting like a "hammer".

Both were flown back to Ireland to testify in the trial that followed a painstaking investigation conducted by Sergeant Conor O'Braonain, under Superintendent Joe Gannon at Pearse Street garda station.

The detectives proved that it was malice rather than a weak heart that caused the convicted burglar to destroy one of the State's most valuable art treasures but the motive continues to elude them.

One garda source speculated that he wanted to "get back at the State".

The enigmatic art vandal was raised in a large family in one of the famous council tower blocks in Ballymun, north Dublin, according to garda sources.

He spent some of his childhood in State care and in recent years he received a substantial award from the Redress Scheme for former residents of State institutions. He used it to buy a house on Willins Way in Ongar in West Dublin, his trial was told.

He told detectives that he was apprenticed as a French polisher and worked in Francis Street - Dublin's antique district. Locals in Ballymun told gardai that a four-poster bed and other antiques had been crammed into his flat there.

Over the years, he has racked up 48 convictions for theft and burglary, including robberies of antiques, the court heard. In 2011, he got a suspended sentence in Wicklow Circuit Court for handling stolen goods including ancient maps worth around €6,000 that dated back to 1651.

He was on a suspended sentence for that offence when he entered the National Gallery in June 2012 and damaged the Monet.

While he was released on bail for that offence earlier this year, he was charged with causing criminal damage to two Felim Egan paintings at the Shelbourne Hotel on January 8.

During a bail hearing in Cloverhill, he shouted abuse at a judge and told a female solicitor that he hoped she lost her baby. Last week, Judge Martin Nolan ordered the jury to find him not guilty of the damage to the Felim Egan paintings.

The Monet painting is now back on display in the National Gallery following a period of restoration.

Sunday Independent