The trial of a 34-year-old man for the murder of his partner's mother has heard she received a violent death.

Kieran Greene denies the murder of 61-year-old Patricia O'Connor on 29 May, 2017.

Mrs O'Connor's body was found in 15 parts in nine locations in the Wicklow mountains in June 2017.

Her daughter, granddaughter and her granddaughter's father deny impeding the apprehension or prosecution of Mr Greene.

The trial at the Central Criminal Court in Dublin heard from a number of gardaí and members of the defence forces who found parts of Mrs O'Connor's body in a number of locations around Military Road in Enniskerry, Co Wicklow between the 12 and 14 June 2017.

Many of the body parts were found near the roadside, in the open. Some had been submerged in water. Gardaí also gave evidence of finding two hacksaws in early January 2018 near the Dodder river in Tallaght.

Detective Garda Janette O'Neill of the Garda Ballistics Section examined the scenes where the body parts were found and was also present when post-mortem examinations were carried out.

She said the opinion she formed at the time was that the deceased did not die at any of the locations were body parts were found. 

She said they appeared to be dumping grounds for the remains. 

Det O'Neill said she was also of the opinion that the deceased received a violent death.

 She said the post-mortem examination of Mrs O'Connor's head showed there appeared to be blunt force trauma to the head and there were a number of visible lacerations and fractures.

The garda was also involved in searches of Mrs O'Connor's home at Mountainview Park in Rathfarnham. 

She described the house as unkempt and untidy throughout with a large number of beds in the bedrooms. 

She said she did not find any signs of a struggle.

Det O'Neill said she found a blood spot on the floor of the bathroom. The hallway and bathroom had been recently painted, badly, she said, and the step into the shower had been tiled.

The court heard that when the blood was analysed it was found not to belong to Patricia O'Connor.

John Hoade from Forensic Science Ireland told the court he compared tissue samples from the human remains with a DNA sample provided by Patricia O'Connor's daughter Louise. The results were fully consistent with her being the mother of Louise O'Connor.

Mr Hoade also examined a number of items found at various scenes including the house in Rathfarnham, Old Military Road, Kieran Greene's car and the suspected shallow grave in Wexford.

He said he attended 66 Mountain View Park in June 2017 where his role was to examine for evidence of blood staining.

On visual examination he found no blood in the bathroom or small front bedroom. Using a chemical called Blue Star he sprayed the bathroom and bedroom and had one positive reaction from the bathroom where a small blood speck was found.

On analysis it was shown to be from a male source and while it was too small to yield a full DNA profile it was sufficient to eliminate Patricia O'Connor, he said.

He also examined a number of items provided by gardaí including a piece of carpet, a child's hurley, red and gold fabric, a table cloth, tiling tools, hammers, a mallet a screw driver, hack saws and found nothing.

Items from Old Military Road were also examined but nothing was found. There was insufficient DNA present on a black plastic bag to generate a profile, he said.

He also examined a Toyota Corolla driven by Kieran Greene but found no traces of blood. Human hair from the scene of the shallow grave in Wexford was examined but there was insufficient DNA to generate a profile, he said. 

During cross-examination he agreed that DNA could degrade over time.

He agreed that samples from some items had been sent to the UK for a different type of DNA testing