Master and Slave:Graham Dwyer·Elaine O'Hara

Elaine O’Hara was a childcare worker from south Dublin, Ireland. On August 22, 2012, she was last seen near Shanganagh Park in Shankill, and she was never heard from again. With no clear evidence of a crime, her disappearance was treated at first as a probable suicide.

In September 2013, a dry summer had lowered the water in Vartry Reservoir in County Wicklow. On September 10, anglers found handcuffs, restraints and other items in the shallows, and gardaí later recovered two phones from the water. Three days after the anglers’ find, a dog walker came across human remains on Killakee Mountain in the Dublin hills, and dental records confirmed they were Elaine’s. The phones held messages between two users in a master-and-slave relationship. Details in those texts, backed by phone records and DNA, pointed to Graham Dwyer, a married architect. He was arrested on October 17, 2013.

In March 2015 a jury at the Central Criminal Court convicted Dwyer of murder, and he received the mandatory life sentence. He then challenged the use of his phone data under Irish retention law. The EU Court of Justice ruled in 2022 that the law breached EU rules, but in July 2024 Ireland’s Supreme Court unanimously upheld his conviction.