A 34-year-old man accused of the murder of his mother-in-law told gardaí she tried to kill her husband and wanted all the family dead, the Central Criminal Court has heard.
Kieran Greene denies murdering 61-year-old Patricia O'Connor, the mother of his partner, Louise O'Connor.
Louise, her daughter Stephanie and Stephanie's father Keith Johnston all deny impeding the apprehension or prosecution of Mr Greene.
Mr Greene was arrested on 13 June 2017, after bringing gardaí to the scene of a shallow grave in Co Wexford, where he said he had buried Mrs O'Connor before returning some days later and cutting up her body.
He told interviewing gardaí that there was not one day that Mrs O'Connor did not "give out or assault". It was basically just constant, he said. He described it as "horrific stuff" and said the kids hid under the table.
The jury has heard that Mr Greene lived in the small four-bedroom house at Mountainview Park in Rathfarnham with his partner Louise O'Connor, her five children, as well as Mrs O'Connor and her husband, Gus.
Mr Greene said Mrs O'Connor used to throw the kids' Christmas toys out and spent all the money her husband had saved.
He said his father-in-law "supposedly" fell down the stairs twice, but the second time, he felt she tried to kill him by doing something to make him fall down.
He told gardaí Mrs O'Connor wanted her husband dead and had told his partner, Louise, that if she killed her dad, she would sign the house over to her.
Louise had been diagnosed with a condition called Graves' disease and her mother said there was a symptom called "Graves' rage", which would allow her to kill anyone and get away with murder.
Mr Greene said Louise automatically said no. He said Mrs O'Connor had been saying she wanted her husband dead for years.
Mr Greene also told gardaí he believed his mother-in-law would have harmed his children. He said he felt for everyone's safety in the house. He said he had told loads of people but nothing happened.
He said the kids had a nightmare of a life with her in the house.
Mr Greene said he believed Mrs O'Connor had put penicillin in Louise's drink, knowing she was allergic to it. He said he believed his mother-in-law was trying to kill them, but he could not prove it.
He explained he felt free after throwing her body parts around the Wicklow Mountains because he felt his kids would be safe, and they would not have to fear her any more. He said doctors, social workers and the head of housing for the council, had all come to the house.
He said he was fearful Louise and her eldest daughter would take their own lives. He said no one was helping them.
But Mr Greene said on the night of 29 May 2017, Mrs O'Connor attacked him first with a hurley. He said he had definitely hit her twice, although he said it could have been a little more. He said he did not go to hospital for his injuries.
He said he felt terrible, stressed and angry as he hit Mrs O'Connor. He said he did not purposefully "bang bang" until she was dead.
He told gardaí it was not planned, it was not intentional and he was defending himself. "If I wanted to kill her, why would I wait ten years?" he asked.
Mr Greene said he did not shout for help from the other people in the house and did not know why Mrs O'Connor had not shouted for help.
He said he asked her why she hit him and she replied that she wanted them all dead, she wanted them out, she wanted them dead.
He said she wanted her husband dead and wanted everyone dead all the way down to the kids. He said he was not a bad person.
Mr Greene said he did not call an ambulance because he panicked. He said she would have said he had hit her first and she would be believed. He said he let her die because his kids would be safe.
A 'ghoulish enterprise over some days'
The former Deputy State Pathologist Dr Michael Curtis gave evidence of carrying out post mortem examinations on 15 different parts of Patricia O'Connor's body over four days from 11-14 June, 2017.
It was described by Kieran Greene's defence counsel, Conor Devalley, as a "ghoulish enterprise over some days".
Dr Curtis said when the first part of Mrs O'Connor's body was found, the only way of identifying the gender of the person was through DNA testing and a very primitive way of measuring the bones.
He said although DNA testing confirmed the body was female, the initial measurements of the bones put it as being in the male spectrum on anthropological charts.
He said traces of alcohol were found in the body but no trace of drugs.
Dr Curtis said Mrs O'Connor's entire body had been recovered. He said the body parts had sharply cut bone edges and soft tissue and in his view the act of dismemberment had most probably been carried out with a power tool such as a reciprocating saw.
There was more irregularity on her severed wrists and hands he said, raising the possibility they had been removed with just a non-powered hand held saw.
He said death was caused by blunt force trauma to the head. He said a minimum of three blows had been struck with a solid implement.
Dr Curtis said there was no evidence of any typical defensive type injuries to Mrs O'Connor's hands or forearms.
Under cross-examination by lawyers for Mr Greene, he said he would have thought Mrs O'Connor was a stocky person.
He said it was not possible to exclude the possibility that one of the wounds to her head could have been caused by falling onto a shower step and it was probable the fatal blow had caused her death rather rapidly.
Earlier, the court heard Mr Greene told gardaí he had chopped up the body and scattered it in the mountains on his own. He could not explain why there was no blood in his car.
He agreed that Louise O'Connor's former partner, Keith Johnston had been seen on CCTV with him at a Mr Price shop on 9 June, 2017 when he bought a petrol can, tow rope and plastic blades.
But he said Mr Johnston knew nothing about what had happened to Patricia O'Connor.