A man who deliberately robbed a jewellers' shop because he wanted to be in prison for his own safety has been jailed for three years. Dublin Circuit Criminal Court heard that Liam Gaynor (48) was "institutionalised" in prison, having spent 20 years of his life behind bars.

He was caught by gardaí crouching in the roof of McManus's Jewellers, Georges Street in Dun Laoghaire after he had held up staff and robbed two diamond rings.

Gaynor, of York Road in Dun Laoghaire, pleaded guilty to robbery and criminal damage at the jewellers on October 19th last year.

He told gardaí he was under threat from moneylenders and feared his seriously ill mother would be burnt alive if he was not in jail.

Passing sentence, Judge Desmond Hogan accepted that Gaynor had been genuinely in fear.

He sentenced Gaynor to three years in prison but suspended the final 12 months on condition that he keeps the peace for four years on his release.

Judge Hogan said it was a serious offence and told Gaynor, "It's time for you to be getting a bit of sense". Garda Robbie Keogh told Sinead McMullan BL, prosecuting, the robbery had taken place shortly after 10am.

Gardaí were called to the scene to find Gaynor trapped in a cubby hole above a suspended ceiling, after he had failed to escape through the roof.

The court heard he had run into the shop with a scarf over his face and his hoodie up, shouting "This is a robbery, get on the floor".

He had made a gun gesture with his hand underneath his jumper and robbed two gold diamond rings - one of which he flung into the attic where staff were unable to find it.

Gardaí threatened to pepper spray Gaynor if he did not come down from his perch - but he did so and handed over the second diamond ring which he had secreted in his sock.

Gaynor was arrested and apologised to staff members, apart from the owner of the shop. He said the robbery had been a personal attack on the shop-owner and that if he had had a gun he would have shot him.

Gaynor said he had picked up a fire extinguisher and had started smashing the door and throwing stuff around in order to make things difficult for the owner.

He told gardaí he had not worn gloves because he expected to be caught.

Gaynor said he needed €800 to repay a loan to moneylenders as he was starting a horticulture course and needed books and equipment. He has 34 previous convictions including theft, larceny, robbery and possession of firearms.

Marie Torrens BL, defending, said it was fair to say her client was institutionalised. She said Gaynor is very intelligent, genuinely interested in horticulture and has "given her some tips" for her garden.

The court heard that Gaynor had a drug problem but has reduced his methadone. His sentence was backdated to October 19th, 2013.