A SUMMER evening in July 2011 was "chosen" by a man the prosecution claims is Graham Dwyer to "go out and find someone to kill", the Central Criminal Court has heard.
ut, according to text messages read out at the trial of the Cork-born architect, the planned killing had to be cancelled because a man using an 083 number - which the prosecution says is Mr Dwyer - received a visit from his brother.
Mr Dwyer (42) is charged with murdering Ms O'Hara at Killakee, Rathfarnham, Dublin on August 22, 2012, hours after she was discharged from a mental hospital.
The father-of-three of Kerrymount Close, Foxrock, Dublin, has pleaded not guilty to murdering the 36-year-old childcare worker on that date.
Yesterday, the jury of seven men and five women heard that Ms O'Hara received a text message from the 083/"Sir" phone about the planned killing in July 2011 - a year before she went missing.
"We're going to have to do it next week. My brother has called over," said "Sir".
"Bad timing," Ms O'Hara replied.
"Really bad, but maybe he saved a girl's life," he said, to which Ms O'Hara replied: "Maybe".
The trial has heard that Ms O'Hara was last seen in Shanganagh, south Dublin on the evening of August 22, 2012. A cause of death could not be determined when her skeletal remains were discovered at Killakee on September 13 the following year.
It is the State's case that Mr Dwyer stabbed her for his own sexual gratification.
Among more than a thousand messages read to the Central Criminal Court yesterday were texts about how the sender would kill Ms O'Hara in woods without her consent.
The sender of the messages also asked Ms O'Hara to find him someone else to kill.
Yesterday prosecutor Sean Guerin SC read out texts from a chart of more than 2,600 text messages prepared by crime and policing analyst Sarah Skedd. The messages, the court has heard, were recovered from various devices in the investigation.
Ms Skedd spent yesterday confirming the contents of text messages between Ms O'Hara and the 083/"Sir" phone that the State said the accused purchased in the name of Goroon Caisholm on March 25, 2011.
They included messages from the 083/"Sir" phone to Ms O'Hara to help him get his "knife into some flesh soon".
"I'll do my best Sir. If you want you can kill my sister," she suggested, later clarifying that she was "only kidding".
The 083/"Sir" phone later texted Ms O'Hara: "Will have to find me a victim to stab. That's an order" and Ms O'Hara asks "Sir": "How do I do that?"
"We will go out for remote walks ... and strike if conditions are right," he replied.
"I will prepare hunting bag with things for the murder," he wrote later.
"Sir" warns Ms O'Hara that he could bring her out of her apartment in a suitcase, but not if she helps him stab someone.
In one exchange "Sir" ask Ms O'Hara, who repeatedly says she does not want to be stabbed, how many times he could stab her.
"I'm a sadist and enjoy others' pain. You should help me inflict pain on you and help me with my fantasies," he wrote. "Help me rape and stab a young girl ...You help me stab a girl and you won't get knifed."
Ms O'Hara texted "Sir" on April 26 to ask when they would be doing it (the murder).
"Will you be able to handle all the blood?" he asked. "I don't know, Sir," she replied.
The trial continues.