A convicted murderer who dismembered his victim's body with a chainsaw threatened that if he did not put a bullet in his own son - who is accused of impeding the murder investigation - "the IRA would", a trial has heard.

The Central Criminal Court also heard today that accused Paul Wells Junior asked gardaí to handcuff him in the district court as he was afraid he would attack his father Paul Wells Senior.

Paul Wells Snr (51), of Barnamore Park, Finglas in Dublin 11 was found guilty of murdering Kenneth O'Brien at his home in Finglas on January 15 or 16, 2016. The killer admitted that, after shooting the 33-year-old father in his back garden, he dismembered his body with a chainsaw and dumped it in a suitcase in the Grand Canal.

The accused man, Paul Wells Jnr (33), is charged with impeding the apprehension or prosecution of his father Paul Wells Snr by disposing of a chainsaw in Co Kildare nearly four years ago. The prosecution allege the accused did so knowing that his father had taken a life.

The jury was today listening to further garda interviews in the trial of Mr Wells Jnr.

Evidence has been given that Mr Wells Jnr made a voluntary statement to gardaí at Leixlip Garda Station on February 5, 2016 and was arrested the next day on suspicion of murdering Mr O'Brien with a firearm.

In cross-examination today, Sergeant John O'Keeffe told defence counsel Damien Colgan SC that the accused suffered a panic attack during his sixth interview with gardaí on February 7.

Sgt O'Keeffe agreed with Mr Colgan that Mr Wells Jnr said mid-interview that he "could pass out" and was finding it hard to concentrate as he thought he was about to have a panic attack. Following this, gardaí terminated the interview and a doctor was called to the station.

Sgt O'Keeffe also agreed with the barrister that the accused had said he was feeling dizzy and collapsed on the floor of the custody area. A 999 call was made and an ambulance dispatched to the station.

The witness agreed that Mr Wells Jnr was complaining of chest pains and had a history of suffering from panic attacks. Ambulance personnel conducted an ECG on the accused in order to rule out any cardiac issues, said Sgt O'Keeffe.

The doctor administered medication to the prisoner and he was deemed unfit for questioning for six hours. He was allowed to rest before he was brought to the district court that night in order to seek an extension to his detention period.

Sgt O'Keefe agreed with Mr Colgan that he was aware of a complaint made by Mr Wells Jnr against his father Wells Snr. The court heard a threat had been made by Wells Snr to the life of his son, when his daughter had visited him in prison.

Mr Colgan put it to the witness that Wells Snr had indicated that Mr Wells Jnr was going to have a bullet put in him and if Wells Snr did not do it, then other persons notably the IRA would. Sgt O'Keeffe indicated this was the case.

Sgt O'Keeffe agreed that Wells Snr also said to his daughter: "I won't have to when the IRA find out, they will do it."

Wells Snr's daughter informed the accused about their father's threat and an investigation was carried out, the court heard.

Sgt O'Keeffe further agreed with Mr Colgan that when Wells Snr was interviewed by gardaí about his conversation with his daughter, he mostly said "no reply" and denied using those words.

In his seventh interview on February 8, truck driver Mr Wells Jnr told gardaí he was sorry for saying he had driven to The Curragh in his personal car to dispose of the chainsaw blade and chain, when he had used the company jeep. He said the reason he had a panic attack was because he was "holding back stuff". "I keep imagining what Kenneth could possibly look like in the coffin," he remarked, adding that he could not bear to think that his father had got him into something he had nothing to do with.

"I would never help my father do something so cowardly. I'm only getting rid of evidence to protect my family and not help him [Wells Snr]," the accused told gardaí.

Mr Wells Jnr further told gardaí that his father gave him €11,300 for his mother but disputed it was payment to help Wells Snr get rid of the chainsaw. "I rang my mum straight after and told her," he said.

Mr Wells Jnr also told gardaí he had pulled into a grassy verge at The Curragh on January 20 and spent up to fifteen minutes thinking abut what he should do. He placed the blade of the chainsaw in shallow water and its chain on a thorny branch so that people looking for the weapon would find these items and come forward, he said, adding that he could have thrown them into the middle of the pond. He contemplated committing suicide at the time but thought of his daughter, he said.

Mr Wells Jnr said he was terrified of being shot dead so did not bring the parts of the chainsaw to the garda station.

The accused told gardaí his sister had texted him about their father looking for ratchet straps but he did not think anything of it at the time.

In cross-examination, Sergeant Aine O'Sullivan told Mr Colgan it was "quite evident" the accused was a "vulnerable individual" and agreed he had asked to be handcuffed in the district court as he was afraid he would attack Wells Snr, who was present at the time.

The accused protested to gardaí in further interviews that he had nothing to do with killing Mr O'Brien and said the deceased was a family man like him. "I had no involvement with the murder of Mr O'Brien, charge me with the chainsaw, my head is bursting," he said.

In another interview, Mr Wells Jnr told gardaí that his dad had asked him to get a van and some plastic around three weeks before Christmas in 2015. The accused said his father enquired if he knew anyone who had a pick axe or a shovel, which he could borrow. Wells Snr asked his son for these items again at the beginning of January 2016, he said.

In summary, Mr Wells Jnr said he did not receive the chainsaw knowing it was used in the murder of Mr O'Brien and denied disposing of it in order to conceal evidence.

"He [Wells Snr] is not a human being, he is a monster, I hope the cunt hangs himself," he said.

Mr Wells Junior, with an address at Beatty Park, Celbridge, Co Kildare has pleaded not guilty to disposing of a chainsaw motor at a time unknown between January 19 and 20, 2016 in Co Kildare and not guilty to disposing of a chainsaw blade and chain on January 20, 2016 in the same location.

The trial continues on Monday afternoon before Ms Justice Carmel Stewart and a jury of six men and six women.