The jury in the trial of a 50-year-old man who shot his friend and dumped his dismembered body in a canal in January 2016 will begin deliberating on a verdict on Monday.

Paul Wells Snr of Barnamore Park, Finglas has admitted shooting Kenneth O'Brien and dismembering his body.

However, he denies a charge of murder and claims to have shot Mr O'Brien as they struggled during a row.

The jury was sent home this evening after listening to closing arguments from the defence and the judge's charge.

Mr Justice Paul McDermott said there were disturbing elements in the case in relation to the disposal of the body but he said the "horror that might have been felt at what happened" should not necessarily determine the guilt or innocence of Mr Wells.

He said the main issue was how Mr O'Brien died, how his death was brought about and the circumstances of his death.

He told the jury to consider the state in which the killing was done, whether it was intended or not, or was self defence or not.

However, he told the jury that it could consider something done afterwards to cover his tracks 'if it's suggested that it indicates state of mind on the part of the perpetrator.

The judge said there were three possible verdicts open to the jury: guilty of murder, not guilty of murder but guilty of manslaughter, or not guilty.

The jury had earlier heard the conclusion of the defence's closing speech.

The accused man has claimed that the row happened because Kenneth O'Brien had asked him to kill his partner Eimear Dunne and Mr Wells refused to do it.

After Mr O'Brien was shot, Mr Wells dismembered his body in his back yard in Finglas with a chainsaw, and threw the remains in the Grand Canal.

He claims he panicked about disposing the body and chopped it up using a chainsaw he had borrowed from the deceased.

He was arrested after his son Paul Wells Jnr, "self reported" to gardaí and said he had been asked by his father to dump a chainsaw.

The prosecution told the jury the killing was not just murder but was a premeditated execution.

Senior Counsel Sean Gillane said his story about shooting during a struggle did not add up because the post-mortem examination had shown Mr O'Brien had been killed by a single shot from a gun which had been pressed against the back of the head.

He pointed to evidence that Mr Wells knew his wife and son would be away that night and had told another son not to come to home on the night of the shooting.

Mr Gillane said the story about Mr O'Brien wanting his partner killed was "a nonsense wrapped in self defeating contradictions".

However defence counsel Michael O'Higgins told the jury the evidence supported Mr Wells Snr's claims about a murder plot against Eimear Dunne.

He said it was clear that Kenneth O'Brien had been lying about where he was to be on the day he was shot, his passport and a suitcase were missing from his house and he had deleted phone numbers of his employers from his partner's phone.

The trial also heard he had been in a relationship with a woman in Australia and had told his employer there he would be returning after Christmas.

He told the jury to consider a number of other facts which Mr Wells had disclosed which at first seemed improbable but turned out to be true.

He said while the prosecution had sought to discredit his claims about the plot to kill Ms Dunne, it had not put forward any other reason for the killing except a vague mention of money.

The trial heard that Mr O'Brien had transferred around €50,000 to Paul Wells bank accounts while he was living in Australia.

Mr O'Higgins said on a legal level whether the row was over money or a request to kill his partner it was largely irrelevant because "you will finish at the same point where a gun was taken up and fired in a manner that was justified by law."

If the jury believed that Mr Wells honestly believed the gun could have been used on him that night and he had discharged it in self defence the law provided that you were entitled to "fight fire with fire"  then they must acquit, he said.

He also said that if the jury believed Mr Wells honestly believed his life was in danger but fired the gun in an overreaction they could find him guilty of manslaughter.