A Westmeath drug addict who targeted and robbed a man with the mental age of a 12 year old has been jailed for four years.

After the robbery Darragh Losty (22) told his mother that he was in danger of “forgetting to tie his shoe laces” because he was too afraid to attend a remedial clinic since the mugging.

Mullingar native Thomas Greene McDonagh (22), who was of no fixed abode in Rathmines, Dublin pleaded guilty at Dublin Circuit Criminal Court to robbing Mr Losty at O’Connell street on January 13, 2014.

Mr Losty has special needs as a result of Freidreichs Ataxia, a rare degenerative disease that affects his motor and speech skills. Garda John Saunderson told Judge Martin Nolan that it would be obvious to anyone that Mr Losty had special needs.

Judge Nolan jailed McDonagh for four years and backdated the sentence to last January, when he went into custody for this offence.

Garda Saunderson told Elva Duffy BL, prosecuting, that the mugging took place on the first day that Mr Losty was trying to independently travel to the Central Remedial Clinic (CRC) in Clontarf via bus.

The HSE had previously stopped funding taxi transport to the clinic from his home in Dublin city, the court heard, and significant work had been done to train Mr Losty to travel on his own using two bus journeys.

Mr Losty was on his way home when McDonagh approached him and walked along with him to the stop for his second bus. McDonagh began trying to entice him away from the bus stop by offering to sell him drugs and saying he knew his sister.

Mr Losty kept saying he had to wait but McDonagh managed to get him to come behind a wall. He then put his hand around Mr Losty's neck and threatened him, saying “stop fucking with me”.

The victim told gardai later that he was so scared he thought he was going to die. McDonagh took the man's coat, hat, mobile phone and bus pass. He threatened Mr Losty to stay where he was after he left.

The victim did not move but after a while he realised he could leave. He approached a number of people on the street but he had difficulty getting help until one man stopped to assist and rang Mr Losty's mother.

As part of the investigation that followed gardaí viewed 300 hours of CCTV footage from 34 business and cameras.

McDonagh was identified and arrested. He claimed he didn't think there was anything wrong with the victim and said it was Mr Losty's idea to give his coat away.

He said he was out of his head on heroin at the time and he apologised for taking the phone. McDonagh has 40 previous convictions including burglary, attempted robbery and assault causing harm.

Sandra Frayne BL, defending, said that her client believes that this was the worst crime he has committed and he is extremely ashamed of it.

She said he was born in Mullingar and had been exposed to domestic violence as a child. He was in the care of the HSE from an early age and began dabbling in drugs in his early teens.

His first conviction, at the age of 14, was for possession of a replica handgun with criminal intent. At age 16 he began abusing heroin. She said he is extremely ashamed.

Ruth Losty, the victim's mother, said that this crime had changed her son's life dramatically. He hasn't attended at the CRC since the robbery and she said he'd be a vegetable only for the help of family and friends.

“He can't go from A to B on his own. He needs to be constantly reassured.”

She said she has had to fortify her home because of his fears that McDonagh would attack the house.