A Dublin architect with a sexual desire to stab women has been jailed for life for the murder of Elaine O'Hara, who suffered from mental illness.
Graham Dwyer was characterised as a "sadistic and brutal pervert" who killed O'Hara who was mentally ill, and left her body in mountains near Dublin in September 2013.
Explicit videos shown at the Irishman's trial revealed he had filmed himself stabbing several women while having sex, including O'Hara.
Dwyer lured O'Hara to the Dublin mountains and killed her in August 2012 - just hours after she was discharged from a mental health hospital, according to a Belfast Telegraph report.
A final, chilling text message was sent by Dwyer to Hara was read out to the jury: "Go down to shore and wait."
The architect's crime was only discovered because evidence he had thrown into a reservoir was exposed during very hot summer which lowered the water level.
Judge Tony Hunt said Dwyer showed no remorse for his crime, carrying out an "almost execution" of the vulnerable childcare worker.
Hunt told the court that he "110% agreed" with the jury's decision based on the evidence - which on three occasions was too gruesome for the public to be hear in the court.
Obsessed with BDSM
Because of the horrific nature of some videos, photos and documents, the judge cleared the public galleries.
O'Hara's body was found, along with a gimp mask, restraints, ropes, keys and mobile phones in the Vartry Reservoir, 13 miles from the murder spot.
On the mobile phones were text messages revealing details of the affair between Dwyer and O'Hara whom he had met online.
The 42-year-old from Foxrock was described by the prosecution as "a sadistic and brutal pervert with nothing on his mind other than murder".
Dwyer, who was obsessed with BDSM, said in one text message: "I want to stick my knife in flesh while sexually aroused. Seeing blood turns me on and I'd like to stab a girl to death sometime."
O'Hara's father told the court how he had been haunted by the loss of his daughter, who had been killed in the "most brutal, traumatic and horrifying manner."