The conviction of Graham Dwyer and the unravelling of an almost-perfect murder

Cormac O’Keeffe catalogues the painstaking policing and investigative work, as well as the chance discoveries, that contributed to the conviction of Graham Dwyer for the murder of Elaine O’Hara. (This article was originally published in March 2015)

The conviction of Graham Dwyer and the unravelling of an almost-perfect murder

IT was very nearly the perfect murder. That was how prosecution counsel Seán Guerin SC described the killing of Elaine O’Hara on the opening day of the Graham Dwyer murder trial.

Graham Dwyer with a model plane. His interest in model aircraft was referred to during his trial.

But Dwyer’s perfect plan could not have factored in the unusually dry Irish weather and was trumped by superb policing and investigative work.


On the evening of September 10, 2013, three Wicklow friends — Mark Quinn and brothers William and James Fegan — bumped into each other on a bridge over Vartry Reservoir in Roundwood.

They were commenting on how low the water was. William Fegan subsequently told the court there would usually be about 20ft of water under the bridge, but there was only 12in-18in that day.

Mr Fegan said that a “shiny metal object” caught their attention, setting off a momentous chain of events. It so happened that Mr Quinn had in his van a tension strap with a hook at the end, and was able to use it to fish some things out of the water. First came a rope, then handcuffs and what appeared to be leg restraints.

As it turned out, the items included: A rusty chain with two cuffs on either end; bondage cuffs, comprising long straps with padded restraints and buckles; a ball gag, which comprised a ball, strap and buckle; a black blindfold with a Velcro strap; a hoodie; and and a vest.

The following day, September 11, William Fegan bagged the items, brought them to Roundwood Garda Station, and handed them over to Garda James O’Donoghue.


Garda O’Donoghue’s actions were crucial and a testament to both his gut instinct and professionalism. When he took the items from Mr Fegan, he hung the clothes out to dry and preserved the rest in evidence bags.

He then went to the bridge, but couldn’t see anything in the water.

In a remarkable coincidence, a dog-walker made another crucial discovery in Killakee, in the Dublin Mountains on September 13, just three days after the Vartry find. Magali Vergnet said one of her dogs was scratching in nearby woods as she was putting other dogs into her car. When she went over she saw some bones and, close by, some clothing. She called landowner Frank Doyle and they both examined the area again later that afternoon. This time they found a jaw bone and human remains and alerted gardaí.

Garda Alan Young went to the scene and saw the jaw bone, a rib cage, tracksuit bottoms, and a runner.

Garda O’Donoghue went back to Vartry on September 14, two days after his first visit. He later explained that the “nature of what was found” had caused him to go back and “search and search”.

He told the court he still couldn’t see anything from the bridge, and climbed over a wall and stepped down to the reservoir bed as close as he could to the water’s edge. Still, he saw nothing.

Not giving up, he went back a third time, two days later, on September 16. This time it was sunny and there was no wind.

“I could see a shining object in the water,” he recalled. “What I saw on that occasion was the stock end and part of a loop or a handcuff. They were partially buried.”

He climbed down the embankment and this time stepped into the water. This raised the silt and the visibility was zero, he said. He put his arms into the water and searched by touch.


Garda O’Donoghue pulled out a set of keys — which turned out to be another crucial discovery. On the key ring was a Dunnes loyalty card. He also found a bondage mask, a knife, an inhaler, and a long chain.

He contacted the store and discovered the loyalty card belonged to Elaine O’Hara of Belmarine Plaza, Stepaside. When he ran a name check, he learned she was registered as a missing person. She was last seen at Shanganagh Cemetery more than a year previously, on August 22, 2012.

Garda O’Donoghue rang his superiors and sealed off the bridge. The Garda Water Unit was called in. He then called Garda Wayne Farrell of Bray Garda Station to the scene on September 17.

Garda Farrell got a shovel and dug out other objects, including a Nokia mobile phone. The water unit found other sex toys and, thanks to a metal detector, located another Nokia mobile phone with a sim card.

The discovery of these Nokia phones was to prove crucial in the investigation.

The water unit also located a pair of glasses. Using an eight-digit code on the side of the frame, the retail manager of Specsavers in Dun Laoghaire identified the owner of the glasses as Ms O’Hara.

Back at the Killakee investigation, an examination on the jawbone provided another key link. Mary Clarke, a specialist oral surgeon at the Dublin Dental University Hospital, examined the jawbone on September 16 and 17.

Killakee forest, where Magali Vergnet found the body of Elaine O’Hara while walking her dogs in September 2013.

The find matched records they had for Ms O’Hara, who, it transpired, had attended the hospital 47 times in the six years before she disappeared.

This was a major development, as the autopsy had been unable to provide anything that might identify the remains. Some 65% of the remains were recovered, including the skull, forearms, and hands. The autopsy wasn’t able to determine the cause of death.

By this stage, the investigations dovetailed. The two crime scenes related to one and the same person.


The next phase of the investigation threw up a suspect. Detective Sergeant Kevin Duggan said his team examined CCTV camera footage at Belmarine between January 18, 2012 and August 26 of that year.

It logged eight occasions when Graham Dwyer was at Belmarine Plaza.

On one visit, on July 11, Dwyer appeared to have one phone in his hand. He then appeared to put it away and take out a second phone. On the same date, Ms O’Hara was caught on camera taking from her letterbox something which appeared to be a mobile phone.

On August 13, the CCTV captured Dwyer with a backpack, similar to the one found at Vartry. Again, on August 15, he was seen carrying a backpack from the complex and did not return with it.

Senan McShea, Dwyer’s son from a first relationship, identified his dad to gardaí from the CCTV cameras.

A forensic examination of the mattress at Ms O’Hara’s apartment uncovered five stab cuts and three small holes. DNA of semen on the mattress was that of Dwyer. No other third-party DNA was recovered.


Dwyer’s girlfriend from college days, Emer McShea, provided strong information to gardaí. Senan McShea was the son she had with Dwyer in 1992.

She said that Dwyer brought a kitchen knife into their bedroom and would pretend to stab her during sex.

Dwyer’s trial would later hear that he wrote to Senan while awaiting his case.

He wrote: “Everything going well here. All forensics clear and we are sure of an acquittal now we have a mountain of evidence that it was suicide.”

Dwyer’s wife, Emma Dwyer, told gardaí that she recognised a spade found near Ms O’Hara’s remains as one that was missing from her garden. She said the stickers were familiar on the spade, as were splatters of orangy-red paint on it, although forensics did not support the connection.

In a gruesome coincidence, Ms Dwyer said that September 13, the day Ms O’Hara’s remains were discovered, was both her and Dwyer’s birthday and that they were out for dinner that night.

The trial heard that, in a letter he wrote to her while on remand in custody, Dwyer said: “Do not believe the gardaí. They actually have no evidence.”

Dwyer’s sister, Mary Wroblewski, told gardaí that the address used by the person who bought an 083 phone found on Ms O’Hara’s computer was very similar to hers in Co Tipperary, though she said she didn’t notice the first line on the address.

In a crucial piece of evidence, an American woman, called Darci Day, emerged. She later told the trial that Dwyer had mentioned Ms O’Hara to her. She said he had told her that he used to cut Ms O’Hara and that she had asked him to kill her in the past. She said his fantasy was to stab a woman to death during sex.


The discovery of Ms Day was part of a major investigation conducted into computers found at the homes of Dwyer and Ms O’Hara. Her Apple laptop, which was synced with her iPhone, had an 083 number for a person called ‘Graham’. Computer software managed to recover hundreds of texts from the hard drive, where someone who had texted her during 2011 and 2012 made references to a pay cut and his flying.

A later search on Dwyer’s home in Foxrock found two letters relating to pay cuts.

Two female investigators were central to the case against Dwyer.

Detective Garda Brid Wallace in the Computer Crime Unit found a document called ‘Killing Darci’ on Dwyer’s computer. “Having been responsible for creating three lives, wasn’t I entitled to take just one?” he wrote. The document recounted how a woman called Cassie had travelled from the US. He said he had raped and stabbed her, that he slit her throat, and had sex with her corpse.

Ms Day said that she used the name Cassie.

Garda Wallace found an animated video of a female having her throat cut. She also found a folder entitled ‘EH’, which included a document called ‘Diet.doc’ which was authored by Ms O’Hara.

She found a five-second video clip under ‘A&D Wejchert Architects’, where Dwyer worked. Dwyer was the author of the document and last modified it. The document talked about a trip to Newcastle and forcing a woman from a bookshop at knifepoint to his hotel room and described raping and almost strangling her, using chloroform to render her unconscious. He referenced another attack in St Stephen’s Green.

Garda Wallace found 38 videos on his computer, with females in 35 of them and two of them involving himself.

In one, Dwyer stabbed himself and in another he reviewed the use of choloform on himself.

One clip appeared to show a man swinging what appeared to be a knife at a bound woman while having sex with her. At the trial, Dwyer’s defence accepted the video was of Dwyer and Ms O’Hara. Another video showed a naked woman with her mouth covered over, and screaming while a man pushed what appeared to be a knife into her.


A second key investigator in the case was Sarah Skedd, a civilian employee of the force, working as a crime and policing analyst.

Sarah Skedd carried out extensive examinations of phone and toll booth records. 

She carried out mammoth work on two sets of relevant phones, one set involving Ms O’Hara’s phone and an 083 number which was registered to Garoon Caisholm with an address similar to Dwyer’s sister; and a second set of two Nokias found at Vartry Reservoir. The latter were not registered to anyone and were prepaid.

There was a total of 2,600 texts from the various devices. One text from the 083 phone (in the name of Garoon Caisholm) to Ms O’Hara on March 21, 2011 read: “My urge to rape, stab, kill is huge. You have to help me control or satisfy it.”

In the exchange, she asked the man about his wife’s pregnancy. “Promise I can kill you by stabbing,” was the reply.

On April 2, 2011, the man told her he was “stuck here with people visiting baby”. On April 8, he texted: “Killing is my new goal.”

On April 14, in an unknowingly prescient remark, Ms O’Hara said: “You really have to be careful with your phone,” referring to Garda use of satellite tracking. He replied: “Help me rape and stab a young girl... It will be all worth it when I kill you.”

On May 24, he said he was “lucky with last victim” and said he needed the perfect plan. Ms O’Hara responded: “Yes sir, don’t you know, there’s no such thing as a perfect plan.” He described four ways he could kill her.

The trial later heard that the name Garoon Caisholm was a variation of the name Gordon Chisholm, an acquaintance of Dwyer’s. The address for the phone was similar to Dwyer’s sister’s, but with the same inaccuracy he had given his wife and gardaí. In addition, the phone number used when registering this phone was practically the same as Dwyer’s work phone, apart from the prefix.

There were discussions between this phone and Ms O’Hara’s iPhone about getting other phones. These Nokias were purchased in November 2011 and the other two phones ceased contact.

Ms Skedd used motorway toll booth information s to track the user of one of the Nokias. On July 4, 2012, this phone was used in Galway that morning and in the afternoon in Dublin 2. She examined toll booths for cars passing through between 12.30pm and 2.15pm for a vehicle owned by a south Co Dublin owner. She identified a 99G car which, it turned out, was owned by Dwyer.

When she examined the Nokias she found that there was only one number in each. The number in one phone was named as MSTR. In the second phone was a number named as SLV. In court these were referred to as Master and Slave. Ms Skedd said there were 1,369 texts and 11 calls involving them between December 1 2011, and August 22, 2012.

She found that, any time both Dwyer’s work phone and the Master phone were active in the same time period, they used cell sites in the same area. She said there was nothing to contradict the suggestion that the same person was using Dwyer’s work phone as was using the Master phone.

On December 21, 2011, Dwyer’s work phone used a cell site at the ESB HQ on Fitzwilliam Square, near where he worked. The Master phone used a cell site known as Fitzwilliam that same morning. She found the Master phone used a cell site at Howth Harbour at 12.50pm that day and that Dwyer’s work phone used a cell at Howth Yacht Club five minutes later.

On August 21, 2012, the day before Ms O’Hara vanished, Ms Skedd found that the Master phone used a cell called Fitzwilliam, close to Dwyer’s work, to send a message. She said that, up to 4.52pm on August 22, the Master phone had been using a cell close to a phone mast being used by Dwyer’s phone at 4.54pm.

Detective Sergeant Peter Woods, who led the investigation, gave evidence in the trial about the interviews they had with Dwyer on his arrest in October 2013.

He told Dwyer that the Master phone was at Carron, Co Tipperary, when he was there in July 2012. Dwyer said it wasn’t his phone.

Sgt Woods read Dwyer a text sent to Ms O’Hara from the 083 phone concerning the birth of a baby girl. He told him the name was the same as his daughter. He further told Dwyer the 083 phone was registered to his sister’s address. Dwyer said he couldn’t explain that. Dwyer admitted to watching “erotic horror” or gore movies and accepted it was “sick”.

Sgt Woods put it to him he was on CCTV at Belmarine and that his DNA was in her apartment. Dwyer replied: “I can understand how it would be there. I’m not an innocent person, but I’m innocent of murder.”

The detective pointed out to him that his work mobile had not been in any contact with Ms O’Hara in 2011 and 2012, to which Dwyer said: “I can’t explain it.”

He showed Dwyer one of the mobile phones found at Vartry and said to him: “You thought you’d done the perfect crime.” Dwyer replied that it wasn’t his phone.

Sgt Woods said CCTV had captured him carrying a backpack out of Ms O’Hara’s apartment block on August 15, 2012. He said it wasn’t returned and ended up in the reservoir, next to Ms O’Hara’s keys and glasses. “It was a bit sloppy of you,” to which Dwyer replied: “I can’t explain that.”

In the prosecution summing-up, Seán Guerin SC said: “Remarkably, when Graham Dwyer moves, these phones move with him. Whether he’s going to Ballyshannon, Galway, Carron, north of the Liffey... wherever he goes, the phones go. They are stuck to him like a shadow.”

He said the record of the texts held up “a mirror to the life of Graham Dwyer” and that it was “utterly impossible” for it to be anyone else.


At the end, the evidence piled high against Dwyer.

Gardaí and the prosecution linked him to two mobile phones — the 083 phone and the Master phone — and, in turn, to the contents of those texts. They did this through a detailed tracking of the movement of the phones and Dwyer’s work phone, as well as indications as to his identity in certain texts, such as the name and gender of his newborn baby.

Once the link was established, the texts clearly showed a desire to murder Ms O’Hara. This desire was again repeated in the testimony of Ms Day.

Separately, the prosecution established a relationship — a violent sexual relationship — between Dwyer and Ms O’Hara, through computer contact, Dwyer’s own admissions, CCTV footage of Dwyer at Belmarine, and videos of them engaged in violent sex.

The prosecution also clearly established a history of violence by Dwyer against women generally, including against a former partner, and used the testimony of Ms Day, his extensive video collection of gore and his descriptions of him raping and stabbing women, including a woman in Newcastle.

In his closing address, Mr Guerin said Dwyer had stabbed Ms O’Hara for his own sexual gratification in what was an abusive, manipulative and “predatory” relationship.

He said the architect was “a sadistic and brutal pervert with nothing on his mind other than murder” and that the stabbing of Ms O’Hara was the implementation of a plan he had set out in the texts.

Mr Guerin said Dwyer wanted people to think it was suicide in the circumstances of Ms O’Hara’s disappearance, just out from mental hospital.

“It very nearly worked out for him,” he said.

Dwyer thought it was the perfect murder. But, as Ms O’Hara told him, although tragically for her, there’s no such thing.

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