Murder accused Kieran Greene retracted his admission to killing his partner's mother, Patricia O'Connor, telling gardai he was persuaded to "take the rap" after her husband hit her with a metal bar, a jury heard.
Mr Greene changed his account of the killing while in custody six months after he was arrested, saying he felt like he had been "set up" because his partner Louise O'Connor and her ex-boyfriend Keith Johnston were "going back out again".
A Central Criminal Court jury was told that in the garda interview he also alleged Mr Johnston dismembered Patricia O'Connor's body after he asked him for help.
Denying killing her, Mr Greene told gardai: "I honestly didn't do it. I'll swear on anyone's life, I didn't do it, you have to believe me."
Mr Greene (34) denies murdering Ms O'Connor (61) at the house they shared at Mountain View Park, Rathfarnham, on May 29, 2017.
The grandmother's remains were found scattered over a 30km-wide area in the Dublin and Wicklow mountains between June 10 and 14, that year.
He is on trial alongside three other people who have pleaded not guilty to impeding the investigation - his then-partner, Louise O'Connor (41), her daughter Stephanie O'Connor (22) and Mr Johnston (43).
The jury heard Mr Greene said in interview in June 2017 that he had killed Ms O'Connor in self-defence after she attacked him with a hurley.
He said he had first buried her in a shallow grave in a field in Wexford, but returned to move the body, could not lift it and instead dismembered it and scattered the parts.
He insisted in June that he had acted alone at all times. However, on December 9, while on remand at Cloverhill Prison, he asked to speak to the investigation team again and give another statement.
This time, he said that after he "went down on the ground" when Patricia O'Connor hit him, her husband Gus came into the bathroom saying: "What the f**k are you doing?"
He said Patricia swung the hurley at him and missed.
"Mr O'Connor had something in his hand, a black bar or a crowbar, and he hit her on the head," Mr Greene told gardai.
"She fell on the floor. He said, 'I'm defending you so you can take the rap for this'."
Mr Greene brought her up to the bedroom, he said.
Louise O'Connor came down and they told her what had happened. She said "we can't leave her here", and he put her mother in the boot of his Toyota Corolla.
"I started driving," he said, and he went alone to Wexford. When he got back, Louise was cleaning the bathroom.
A couple of days after that, Mr Johnston was informed, he added. "I asked him for help. I had never been in this predicament before," Mr Greene said.
Mr Johnston said "leave it with me", he said, and he came back a day or two later and "made a plan".
They went to some shops, including Mr Price where "he got a petrol can" and they also got Stanley blades, Mr Greene said.
They went to B&Q and bought black bags, a tarp and a hacksaw, then to Woodies and got spare Stanley blades and a hatchet, he said.
"I brought Keith to where the body was buried," he said.
"We dug her up... he started cutting her up with the saw."
He said Mr Johnston put the parts into bags and they put the bags into the boot, "tied them with knots, we did".
He drove to the Wicklow mountains and Mr Johnston "said 'stop'", got out, took a bag from the back of the car and opened and emptied it.
He "kept doing this" until all the bags were gone, Mr Greene said.
Mr Johnston said, "I know this is on you, brother, I have a background on drugs, I can't get into any more trouble," Mr Greene told gardai.
They drove to Dodder Valley Park in Tallaght and Mr Johnston took out the saw and "came back then with nothing in his hands".
They drove to another location and "he burned the clothes".
A day or so later, "he came back down and scraped the grout in the bathroom and shower and painted the walls", Mr Greene added.
"I went and told the gardai I killed her, even when I didn't. We all agreed I would take the blame, why I don't know.
"I feel I shouldn't be taking the blame for all this. I feel like I was set up because Mrs and Keith are going back out. I'm facing a murder charge and they are out there and I'm taking the rap for it."
The only reason he did not say anything sooner was that he was concerned for the kids, he said.
About the clean-up, he said it was with a mop and bleach and "I did the first one and Louise did it then after".
"Keith said, we should dig her up and put her deeper. I didn't know till we got there," Mr Greene said.
Stephanie had dressed up to look like Patricia, he said.
"Her and her ma said she was going to dress up like Patricia to show she had gone missing. I wasn't aware until I came back from Wexford that was what she did," he said.
Stephanie O'Connor said in a statement that she slept all night after her grandmother left and heard no disturbance.
Mr Johnston said in a statement that Mr Greene told him and family members about killing Patricia just before he went to the gardai.
Mr Justice Paul McDermott warned the jury that nothing a defendant said in a statement could be used as evidence against a co-accused.
The trial continues.