A 35-year-old Dublin criminal has been found not guilty of murdering teenager Marioara Rostas in the city six years ago.

The 18-year-old girl died of four gunshot wounds to her head before her body was buried in a shallow grave, where it was discovered four years later.

Alan Wilson, a father-of-four from New Street Gardens in the city, had pleaded not (NOT) guilty to murdering Ms Rostas at Brabazon Street, The Coombe, Dublin between January 7 and January 8, 2008.

The five-week trial at the Central Criminal Court heard that the victim was an ethnic Roma from very poor circumstances in Romania.

She moved to Ireland at the end of 2007 and began begging with her parents and younger brother on the streets of Dublin.

On January 6th 2008, just a fortnight after her arrival here, the family was begging at the junction of Lombard Street and Pearse Street behind Trinity College. Her younger brother, Dumitru, testified that he saw her talking to a man in a car around 2 o'clock that afternoon.

This man told the then 13-year-old boy that he would take Marioara to McDonald's for food and be back in 10 minutes. The family never saw her alive again.

However, a very upset and frightened Mariora rang her brother in Romania the following day and cried for her 'Daddy to come get her'.

Her older brother, Alexandru, said that she said that she was out of town and began to read the letters from a street sign, but the phone cut off.

An investigation began but there were no developments for a number of months.

The investigation then led to the examination of a house on Brabazon Street. This had been the home of Alan Wilson’s sister, Maxine Wilson, and her partner, Fergus O'Hanlon, who was the accused man's friend at the time.

Despite the house having been set on fire that February, two rounds of ammunition and a number of bullet holes were found in a wall there, along with a lock on the outside of a bedroom door.

Dumitru also identified the silver Ford Mondeo in which he last saw his sister. The accused admitted owning this car, but denied driving it at the time.

Both Wilson and O'Hanlon, a convicted criminal, were arrested in October 2008 and questioned about the murder, but no more progress was made in the investigation until late 2011.

Then, while being questioned about another crime, O’Hanlon offered gardai information on the case, and in January 2012 led them to Kippure, a mountainous area on the Wicklow border.

Gardai first found an empty ready-made grave or bunker, but later found the teenager's body lying in a foetal position in a shallow grave. She was mummified in a lot of plastic tightened by duct tape. There was a pillowcase over her head and a knotted sheet wrapped around her legs.

The cause of her death was four gunshot wounds to her head.

O’Hanlon was then admitted into the Witness Protection Programme, was later granted immunity from prosecution and became the State's main witness in the trial.

He testified that on January 8th 2008, he got a call to return to home, where he said Alan Wilson came downstairs holding a firearm.

He said that the accused told him he wanted to show him something and brought him upstairs and showed him a dead girl with a hole in her forehead. O’Hanlon claimed that when he questioned Wilson, the accused replied that she was a witness to her brother being killed.

He said that he felt sick but helped his friend bury her body and later cleaned up the blood in his home.

"It was damned if you do and dead if you don't," he claimed in court.

He said he assisted the accused in preparing her body and placing it in a large lawnmower bag. He said the accused then put her in the boot of his Mondeo.

O’Hanlon said that they drove up the mountains to Kippure, where he said Wilson looked around for the bunker. He said he couldn't find it and that the two of them then dug the shallow grave. He claimed they buried the teenager and burned her belongings nearby.

However O'Hanlon was the subject of a number of days of robust cross examination by defence counsel Michael O'Higgins SC. Mr O'Higgins questioned his motives, noting that he had previously told gardai he hated Wilson and had been recorded saying that he had 'waited four years to f**k him over'.

The barrister also questioned his attitude to women, noting that he had previously been accused of breaking an ex-girlfriend's ribs and that the father of another ex-girlfriend had reported him to gardai for allegedly holding that girl against her will.

Mr O'Higgins showed the jury a photofit prepared from the description given of the driver of the Mondeo. O'Hanlon denied that it looked very much like him. He said he had refused to participate in a formal ID parade because he always refused such requests.

O'Hanlon agreed that he sometimes drove Wilson's Mondeo but denied driving it that day and picking up Marioara himself.

O'Hanlon insisted that he was telling the truth but Mr O'Higgins told the jury that it had got 'a master class in perjury' from him.

Prosecutor Seán Gillane SC said that, given the context, the evidence was never going to come from an altar boy. He said that O'Hanlon had already gotten away with his crime of assisting a killer when he decided to help gardai.

Mr Justice Patrick McCarthy warned the jury of 10 men and two women that O'Hanlon was an accomplice and a beneficiary of the Witness Protection Programme. He informed them that it would be dangerous to convict on the basis of his uncorroborated evidence.

The jury spent just two hours and 53 minutes deliberating today before reaching a unanimous verdict of not guilty of murder.

Wilson showed no reaction to the verdict before returning to prison to finish serving a seven-year sentence for a meat cleaver attack.

The victim's family left with support staff. Nobody stands convicted of their child's murder.