Manuela Riedo arrived in Galway on 6 October 2007 from her native Switzerland. She came to Ireland to study English. Two days later, she disappeared. A search was launched and her body was located the following morning at Lough Atalia in the Renmore area of the city. A murder investigation was launched.

Gerard Barry was arrested a few days later. Barry, of Rosan Glas, Rahoon, gave statements to the gardaí denying that he had anything to do with the death of 17-year-old Riedo.

He said that he had woken up at 3pm on the day in question, had driven around with his brother and friend and went to Salhill. He said he hadn't gone into Galway that day.

"Neither did I walk along the railway line to Renmore," he told the gardaí. "It's three weeks since I used it to get to my mother's house." The railway line ran along near where Riedo's body had been found.

During the six-day trial at the Central Criminal Court, it emerged that a condom had been found "snagged in a bush" at the scene of the killing. A DNA profile ex­tracted from the contents of the condom matched that of Barry.

The court was told that the chances that a person unrelated to Barry having the same profile would be one in a thousand million. The state pathologist, Marie Cassidy, told the court that death was due to compression of the neck. She also detailed a number of injuries on the dead teenager, including one to the left groin, which she said would have been caused by a sharp implement. This injury, the pathologist said, appeared to have been inflicted after the girl had died.

Mobile phone evidence was introduced which showed that calls from Barry's phone bounced off a mast close to the scene of the killing on the night that Riedo disappeared.

Last Wednesday, 29-year-old Barry gave evidence in his own defence. He told the Central Criminal Court that Riedo's death had been an accident. He said he had met her near a shop in Renmore at 7pm on the night in question.

They got talking and he said he'd show her a short cut into the city. She stepped between a gap in the bushes along the way and he thought that she was gone.

He said he sat on a telegraph pole and began skinning a joint. She came back.

"She sat down on the other side of the pole and asked me why I was smoking that. I told her cos I liked the buzz of it. It relaxes me. I asked her if she wanted to smoke it. She said no."

Barry said the couple had sex and that afterwards she said she had to go and meet her friends. "I made a joke, I told her she could even tell them about me," he told the court. She didn't respond. "I kind of sat up and took my arm away. She kind of slid… on the ground. Her head kind of flopped. I shook her and got no response."

He says he then pulled her body to where it was found the following day.

Asked why he lied to gardaí in the days following the killing, he said: "Because I thought if I kept denying it, it'd go away," he replied.

Under cross examination, he was referred to pathological evidence of an unusual injury to Riedo's groin area where a piece of skin had been removed using a sharp object. He said he did not inflict that injury.

"I'm suggesting that you attacked and murdered her," prosecuting counsel Isobel Kennedy said to the witness.

"It was an accident. I didn't mean to cause her any harm," he replied.

On Friday, the evidence concluded and the prosecution and defence gave closing speeches before Judge Barry White charged the jury.

The judge told the six men and six women of the jury to use their common sense in assessing the evidence. He pointed out that the defendant had opted to give evidence, but that did not mean that he was under any onus to prove his innocence.

"If you accept the account given by the accused, then that's the end of the situation," Judge White said. "Or if you're not fully satisfied with it but feel that it might reasonably be true, that's also the end of the prosecution."

He told the jury that, in theory, it had three options. They could find Barry guilty of murder, they could find that he was not guilty of murder but guilty of manslaughter, or they could decide that he wasn't guilty of any crime. However, the defence had admitted the killing, but said it was accidental.

He then addressed the matter of the different versions Barry had provided. In interviews with the gardaí, he had denied being at the scene. In court, he admitted that he had met the victim, and alleged they had engaged in consensual sex.

"The accused man admits that he lied and it relates to a material issue," the judge said.

They would have to decide whether the lie was motivated by "the realisation of guilt and the fear of the truth."

Manuela Riedo's parents Arlette and Hans-Peter, were in court for the duration of the trial. For the most part, the sat and listened to the evidence, although they did become emotional when details of their only child's injuries were read out.