A Central Criminal Court jury have listened to evidence of how a 61-year-old grandmother's head and hands were found in a black plastic bag in the Dublin and Wicklow mountains, which were used as a “dumping ground” for her remains.

The trial of Kieran Greene, 34, also heard today that the results of a post-mortem examination confirmed that retired hospital worker Patricia O’Connor suffered a “violent death”.

A forensic scientist gave evidence that he found no blood-staining belonging to the deceased at her home in Rathfarmham, where it is alleged she received a minimum of three blows to the head with a solid implement in the downstairs bathroom.

The court has heard that the body of Mrs O’Connor was dismembered into 15 separate parts that were found at nine different locations in the Dublin and Wicklow mountains.

Giving evidence today, Detective Garda Janette O'Neill told prosecuting counsel Roisin Lacey SC that she was attached to the ballistics section of An Garda Síochána.

Det Gda O’Neill testified that she attended a scene at Old Military Road on June 11, 2017 where part of a torso had been discovered the previous day.

The torso appeared to be fresh with very little insect activity, something she would have expected if it had been there for a while, she explained.

“The torso part was from below the lower jaw and there were seven teeth present in the lower jaw,” said the witness.

Det Gda O’Neill said she later travelled to Glenmacnass Waterfall and observed another part of the torso located amongst the rocks.

This part from the lower section of the body had most of the internal organs present and there was a strong smell of decomposition, she said.

The witness said she again travelled to two scenes on June 12, where four body parts were recovered.

Det Gda O’Neill explained that a lower left leg was found in private lands at Glenmacnass Waterfall and a right leg, right thigh or knee as well as a right upper elbow were located at Sally Gap.

On June 13, the witness said she went to the location where seven body parts had been found on the Military Road.

A pair of hands and head were found in a black plastic bag and a right foot and a left arm were found nearby, she said.

A piece of a torso from between the eight and eleventh ribs was located half a kilometre away, she said.

The fourth and last part of the torso, which included part of the pelvis and thighs was found in Carrigshouk, she concluded, adding that all body parts found were later brought to Dublin City Mortuary.

It was determined on the evening of June 13 that the body parts belonged to a female and the hands had been sawn at the wrists, she said.

Det Gda O’Neill said the head was badly decomposed with a lot of fly activity and there appeared to be blunt force trauma to the head with a number of visible lacerations on it, she continued.

Detective Garda Janette O'Neill pictured leaving the trial of Patricia O’Connor after giving evidence in Dublin Central Court. Picture: Collins Courts

Det Gda O’Neill said she went back to the river at Glenmacnass on June 14, where part of a left leg and knee had been recovered from the water.

The witness said a thong was found on the lower part of the torso and pelvis. A left foot, the last part of the body, was located at a scene on the Military road, she added.

Det Gda O’Neill said it was her opinion that Mrs O’Connor did not die at any of the scenes where the body parts had been located but they appeared to be “a dumping ground” for all the pieces of the remains.

She told the court that from the results of a post-mortem examination of all the body parts, especially the head, Mrs O’Connor received a “violent death”.

Det Gda O'Neill said she went to Mrs O'Connor's home in Mountainview Park on June 15, where it appeared attempts had been made to paint the hallway and bathroom.

“I don’t know if it was a bad job or done quickly but it was not a good job,", she remarked. She said the bathroom had also been recently tiled.

This afternoon, forensic scientist John Hoade said he analysed tissue samples taken from both the post-mortem examination of the deceased’s remains and her daughter Louise O’Connor.

The DNA profile from the remains were “two million times more likely to be from the biological mother of Louise O’Connor than from somebody unrelated,” he said, adding that this result would be fully consistent with Patricia O'Connor being the mother of Louise O’Connor.

Mr Hoade said he went to the house at Mountainview Park in June 2017 to examine for the presence of blood-stains.

Mr Hoade testified that he found no blood on a visual examination of the downstairs bathroom and a small front upstairs bedroom that had foil on the floor.

The witness said he used a chemical spray called "Blue Star" to see if he could find blood-staining in both rooms. He explained that the spray “lights up” in the presence of blood.

After treating the bathroom, Mr Hoade said he observed a positive reaction for a blood-stain on the bathroom floor, adjacent to the bath panel, in the grout where the tile meets the panel.

This yielded a low level DNA profile from a male source, he said.

The DNA profile was partial because the amount of blood was so small, he said, but was sufficient to eliminate Patricia O’Connor as the source.

No blood was found on a number of items seized from the home at Mountainview Park including a piece of carpet, a child's hurley, hacksaws and a number of sheets, he said.

Mr Hoade pointed out that he also did a DNA test on a knotted area of a black plastic bag in which Mrs O'Connor's head and hands were found and tested it for DNA but there was insufficient DNA to generate a profile.

The inside and boot of Mrs O'Connor's Toyota Corolla car, which Mr Greene was permitted to use, was also examined for blood-staining but it produced a negative result, he explained, adding that the boot mat was missing.

Mr Hoade also examined a piece of hair found in a shallow grave in a field in Killeagh, Blackwater, Co Wexford.

There was insufficient DNA present in the roots of the hair to generate a DNA profile so a sample of it was sent to the UK, he said.

Finally, Mr Hoade noted that he examined two hacksaws and a small axe taken from Dodder Valley Park in Tallaght but no blood were found on these items.

Human hair was attached to the blade of one of the hacksaw's and again this was sent to the UK for testing, he concluded.

Earlier, Private Barry Hannon from Cathal Brugha Barracks said he was part of a "skirmish line" along the Military Road on June 12, 2017.

Two large pieces and one small piece of what looked like "butchered meat" caught his eye around six foot from the roadside, he said.

He reported the find to nearby gardaí.

Private John Curtis also from Cathal Brugha Barracks gave evidence that he was also part of a skirmish line on June 13, when he noticed "a funny smell".

"It was like a rotten meat kind of smell," he continued, adding that there were hundreds of flies flying around what appeared to look like a torso.

"I saw the bottom half of the torso and the top half of the legs and there was underwear wrapped up around the back," he said, adding that the skin was "pinky" and it looked like a pig.

He agreed with Ms Lacey that he thought he could see a spine.

The prosecution allege that Mrs O’Connor received a minimum of three blows to the head with a solid implement at her Rathfarnham home before her body was brought in the boot of her Toyota Corolla car to Co Wexford and buried in a shallow grave.

Her remains were later dug up and the body dismembered using hacksaws and a hatchet over the course of three to four hours.

Mr Greene of Mountainview Park, Rathfarnham, Dublin 14 has pleaded not guilty to murdering Patricia O'Connor at the same address on May 29, 2017.

Louise O’Connor pictured arriving to court yesterday. Picture: Collins Court

The deceased's daughter Louise O'Connor, 41, and granddaughter Stephanie O'Connor, 22, both of Millmount Court, Dundrum Road, Dublin 14, and Louise O'Connor's ex-partner Keith Johnston, 43, of Avonbeg Gardens, Tallaght, Dublin 24 are all charged with impeding the apprehension or prosecution of Mr Greene, knowing or believing him to have committed an arrestable offence, to wit the murder of Patricia O'Connor on May 29, 2017.

Louise O'Connor has pleaded not guilty to agreeing to or acquiescing in her daughter Stephanie O'Connor disguising herself as Patricia O'Connor at Mountainview Park, Rathfarnham, Dublin 14 on May 29, 2017 in order to conceal the fact that Patricia O'Connor was dead.

Mr Johnston has pleaded not guilty to assisting Mr Greene in the purchase of various implements at Woodie's, Mr Price, B&Q and Shoe Zone, Tallaght, Dublin 24 on June 9, 2017, which were to be used in the concealment of the remains of Mrs O'Connor.

Mr Johnston also denies engaging in the refurbishment of a bathroom at Mountainview Park, Rathfarnham, Dublin 14 between May 31, 2017 and June 9, 2017, in order to destroy or conceal any evidence relating to the murder of Mrs O'Connor.

Stephanie O'Connor has pleaded not guilty to disguising herself as Mrs O'Connor at Mountainview Park, Rathfarnham, Dublin 14 at a point in time after her murder on May 29, 2017 in order to conceal the fact that she was already dead.

Mrs O'Connor was first reported missing on June 1, 2017 and a number of her body parts, including her head and hands, were discovered dispersed around a 30kms area later that month.

The deceased had worked at Beaumont Hospital in Dublin and had retired about a year before she died.

The trial continues on Monday before Mr Justice Paul McDermott and a jury of six men and six women.