A man who damaged a £24 million painting by one of Britain's most celebrated artists while in the throes of a psychotic illness has been cleared of criminal damage by reason of insanity.
Keith Gregory, 63, left two deep slash marks in an X shape on The Morning Walk by Thomas Gainsborough when he attacked it with a drill bit in front of horrified art lovers browsing a collection of old masters on the afternoon of March 18.
Mr Gregory, of Kettering in Northamptonshire, caused more than £10,000 of damage before he was dragged away by security guards, shouting that he had just been released from prison and was going to trigger a bomb.
A jury at Southwark Crown Court took just over two hours to unanimously clear him of criminal damage.
Recorder Timothy Fancourt made a hospital order for Mr Gregory to return to a low security unit at Berrywood psychiatric hospital in Northampton where he has been receiving care since March 31.
The court heard from three psychologists on Tuesday who "unanimously agreed" he had been suffering "severe symptoms" of paranoid schizophrenia when he slashed the painting.
Mr Fancourt added: "The defendant has significantly improved in his mental health since that time but it is necessary for him to remain as a patient in hospital and to have continuing treatment."
Earlier on Tuesday, Mr Fancourt advised the jury to consider whether "as a result of that disease it is more likely than not that he either did not know what he was doing when he slashed the painting or that he did not know that what he was doing was wrong".
"If he did not know what he was doing or he did not know what he was doing was wrong then you must find him not guilty by reason of insanity," he added.
The defendant, wearing a green polo neck T-shirt, stood at the back of courtroom as the panel cleared him.
The court heard he felt that people were "closing in" on him when he went to the National Gallery, before damaging the artwork with a drill bit he had been using to remove tape from the cardboard boxes he was using to sleep in.
Mr Gregory, who had spent four months travelling the UK and sleeping rough after absconding from a mental health unit, slashed the painting after hearing a voice which said 'put a mark on the painting and your family will find you'."
He was suffering paranoid delusions and auditory hallucinations, according to Steffan Davies, a psychologist who has been treating Mr Gregory since March 31.
The doctor said Mr Gregory thought he was being monitored by people with laptops and backpacks and that a chip had been implanted in him.
He also believed police were after him for the rape of 30 women, the court heard.
These ideas, Mr Davies said, he "absolutely believed", adding that he was a man "with a perfectly good house, and wife, but because of his illness was homeless and travelling around the country for four months".