Elaine O'Hara, a childcare worker from Ireland, was last seen alive in August 2012 before she vanished nearby to a public park in Dublin.
A shocking discovery over a year later resulted in a high-profile court case and a unanimous conviction against an architect called Graham Dwyer, who had seemingly led a normal life while concealing a sinister secret.
In what has emerged as one of Ireland’s most notorious murder cases, it was revealed that the apparently devoted family man had been living a double life and concealed a lust for sadomasochism that led to him taking O’Hara’s life.
Now a decade on from the conviction, the shocking case is being revisited in a new Prime documentary that aims to shed light on how the case unfolded and the story of Elaine’s brutal murder.
So, what is the new Prime documentary, Murderer Behind The Mask, actually about? Here’s everything you need to know about the case.
What happened to Elaine O’Hara?
Elaine O’Hara was a 36-year-old childcare worker from Ireland who disappeared in the summer of 2012 from Dublin. At the time, she was working extra shifts at a newsagents and considered a popular employee, according to police reports at the time.
But she was also struggling with depression and other mental health issues when she disappeared, and found it hard to cope with the death of her mother. She had received treatment at a psychiatric hospital the morning she went missing.
On the day of her disappearance, O’Hara was meant to work at the Tall Ships Festival in Dublin city centre but instead drove to Shanganagh Cemetery where she parked her car and visited her mother’s grave, with eyewitnesses claiming they heard a woman crying that day near the cemetary.
She then disappeared, and her father later sounded the alarm with Ireland’s Gardaí police force. Due to her background and proximity to some nearby cliffs, her disappearance was initially treated as a suicide until suspicious clues began to emerge a year later.
In September 2013, more than a year after her disappearance, her skeletal remains were found near Killakee Mountain, 15km from where she was last seen alive. It prompted a renewed investigation which eventually led police officers to Dwyer, and the unraveling of a shocking double life.
Who is Graham Dwyer?
Dwyer is a convicted murderer who is currently serving a life sentence for killing Elaine. But how did police eventually make a conneciton between the two?
According to the Irish Times, Dwyer’s friends described him as a man with a short temper who was obsessed with what people thought of him. But he also led a seemingly normal life, working as a partner at A&D Wejchert Architects. He didn’t have a criminal record, was married to a fellow architect and was a father to three children.
However behind the scenes, he had a shocking secret. Behind his wife’s back, he’d started to log onto fetish websites where he spoke about a stabbing fetish he wanted to share with women. He joined the website with the hope of developing a BDSM relationship and it was where he would eventually meet O’Hara.
During the time that Elaine disappeared, Graham is understood to have been in a consensual sexual relationship with her.
In 2013, fishermen on Roundwood reservoir made a creepy discovery of a bag containing bondage gear which included rusted chains and a ball gag. When they alerted police they also found a set of keys that were attached to a Dunnes Stores loyalty card. Investigators were later able to connect the loyalty card to O’Hara.
Subsequent searches uncovered two Nokia mobile phones and a pair of glasses that were traced back to Dwyer due to a number registered on their frame.
Around the same time, a dog walker’s pet had picked up some bones near Killakee Mountain which later led to the grisly discovery of O’Hara’s remains, and blew the case wide open. Subsequent searches of Dwyer’s house resulted in his arrest and charge of her murder.
Graham Dwyer’s trial
Dwyer’s case attracted considerable attention in Ireland and beyond due to the shocking nature of the crime.
A court heard how Elaine was "almost the perfect victim" and was suffering from illnesses that could have led to the conclusion she had taken her own life.
However, as the trial progressed, further sordid details emerged about his fetishes and obsession to use a knife on his partners. The court was also shown several videos of the accused, including ones in which he appeared to stab O’Hara.
Texts read out in court, which proved integral to the case, showed the pair had been in communication for more than a year before her death alongside graphic details of his fantasies.
Throughout the 43-day trial, the court reportedly heard from almost 200 witnesses in a case that seeemingly gripped the nation. Dwyer maintained his innocence throughout, claiming that he did not kill O’Hara but the court decided by unanimous vote that he was guilty.
In 2015, Dwyer was handed a life sentence for the murder of Elaine, with the judge concluding that Dwyer had preyed on her to achieve his own "perverse and debauched desires".
In 2024 Dwyer lost his final appeal when Ireland’s Supreme Court refused to overturn his conviction.
Murderer Behind the Mask is streaming on Prime Video from June 21
