The trial of Graham Dwyer for the murder of Elaine O'Hara has heard the details of almost 420 text messages exchanged between Ms O'Hara, and a number the prosecution alleges was being used by Mr Dwyer.
Mr Dwyer denies murdering Ms O'Hara on 22 August 2012.
Warning: This report contains graphic details
Among the texts sent are messages from the number allegedly being used by Mr Dwyer are texts in which the sender discusses his urge to stab, rape and kill.
They discuss how the man would end Ms O'Hara's life.
And the man asks her to help him find someone to stab and says he knows she would prefer if he stabbed someone else instead of her.
The court heard the contact between the two phone numbers began on 25 March 2011, when the 083 number the prosecution says was being used by Mr Dwyer, texted Ms O'Hara.
He says he is an old friend.
"We used to play together and I miss it terribly," the 083 texter says.
Ms O'Hara tells him "I'm not into blood any more".
The 083 number says he would love to start over. He tells her a girl in the USA asked him to do what she asked him to do. He says he is thinking about it and wants to meet Ms O'Hara for a chat.
She agrees to meet him in a cafe near her home in Belarmine in Stepaside.
The texts make it clear that they resume a relationship.
The 083 texter tells her he got this new phone just so he cannot be traced.
Ms O'Hara tells the texter that she has changed and that he can use her but she is going to use him.
The 083 number tells her that he wants a key and the code for her apartment building as he likes the idea of lying in wait.
In other discussions, the man says he will try to keep her cuts and bruises under her clothes.
Ms O'Hara asks if the man minds if she plays with someone else. The man says he does not mind.
"The more male DNA and fingerprints in your flat, the better", he says, "get his prints on your kitchen knife."
On 28 March 2011, the 083 number sends a text telling her: "My urge to rape, stab and kill is huge. You have to help me control or satisfy it."
She replies: "Control sir. Not satisfy".
On 31 March 2011, she texts him to ask if he is a daddy again.
He replies with the name of his "beautiful baby girl". And continues, "glad you enjoyed the other night. Many more sessions like it to come. See you over the weekend."
When she complains about bruises he tells her to use sudocrem and arnica.
On 1 April 2011 he sends a text saying "still dying to knife someone. Worried I might do it."
He says he will find someone out walking to knife and ask her if she will help.
She says no.
He asks her: "If you ever want to die, promise me I can do it."
"Yes I promise."
Ms O'Hara says it might not ever happen.
Another text sent by the 083 number says "stab stab stab, rape kill".
The 083 number discusses taking Ms O'Hara out of her apartment in a suitcase, off to the woods, for fun and burial.
Ms O'Hara tells the texter she has marks from where he cut her with a blade.
The 083 texter tells her in April that a woman was stabbed in Dublin. And the man got away with it.
He says he would have liked to have been the one knifing her.
"It must have been the most fantastic feeling for him. Lucky guy."
"I am going to do it. You have to help me , or it will be you."
On another occasion he asks Ms O'Hara to help him. She says she will as she would feel guilty if he had to do it on his own.
"Good girl", he replies. "I know you would prefer if I stabbed someone else instead of you."
Another message discussing Ms O'Hara ending her life reads:
"I can't see you as an old lady. If you do decide one day, you have promised me I will send you off."
She says she wanted to do it before but he did not make it easy.
He says "I wasn't ready at short notice. But am now with this untraceable phone".
They discuss how he would end her life.
Jury shown video of Dwyer appearing to stab O'Hara
Earlier, the jury was shown a number of video files found on a hard drive at Mr Dwyer's home, including three clips of him appearing to stab Ms O'Hara.
The videos were not displayed on large screens in the courtroom and screens on the lawyers' benches were turned almost fully away from the back of the court and were not fully visible to members of the media.
The videos showed Mr Dwyer either on his own or with one of three women, one of whom was Ms O'Hara.
The first video showed Mr Dwyer on his own stabbing himself in the leg.
The second video was Mr Dwyer on his own speaking to the camera.
He said he had just woken up having knocked himself out with chloroform and he described how he was feeling disorientated and could hear a loud pounding noise in his head.
The other nine clips showed Graham Dwyer with Ms O'Hara or one of two other women.
The other women's faces were pixelated by gardaí to conceal their identities.
Three of the clips showed Mr Dwyer stabbing Ms O'Hara.
In one of the clips he says "Now that wasn't bad?"
In one, her muffled voice can be heard crying, screaming and shouting.
Detective Garda Brid Wallace agreed that this file had last been written to in October 2008.
There are two clips of a second woman, whose face is pixelated.
Det Gda Wallace said she did not have the dates that those clips were last accessed.
The last four clips refer to a fourth woman.
In one of these clips, Mr Dwyer appears to stab the woman nine times. The woman can be heard screaming and crying.
The last clip is called "fake stabbing" and appears to show Mr Dwyer pretending to stab this third woman.
Three of the last clips were last accessed in 2007 and the last was last accessed in 2009.
Det Gda Wallace also gave evidence of traces of documents found on a hard drive from a computer from Mr Dwyer's workplace.
One document gave an account of a man pretending to be a building inspector for a landlord at a rented premises occupied by a woman.
The man describes checking his equipment which includes rope, chloroform, a plastic bag and a flick knife as well as his fake clipboard.
He introduces himself to the woman as Graham Dwyer and says he is there to check leaks on the roof.
Later he says he realises that he gave his real name and says "that changes things slightly".
Det Gda Wallace also said there was another story about a woman being dragged into a cave and later stabbed to death.
Det Gda Wallace also gave evidence of examining a HP laptop found at Mr Dwyer's house.
Under the username gdwyer/downloads/horror, she said she found images of mutilation and violence against woman.
These images were last accessed on the night of 16 October 2013, the court heard, the night before Mr Dwyer's house was searched and he was arrested.
Det Gda Wallace agreed that a large number of documents had been accessed on that date and she agreed that this could be consistent with some kind of automated scan run by the computer.
Public ordered to leave court for third day
Before the videos were shown to the jury, Mr Justice Tony Hunt ordered members of the public to leave the court for a third day, using a rarely invoked power under the 1951 Criminal Justice Act.
The judge said this was a difficult case but he said cases had to be tried by a jury and the Constitution did not make exceptions for difficult cases.
He said the jurors had to rise above the material to a certain extent.
He told them they had to be judges of the facts of the case and they must put aside the feelings and emotions that might understandably arise by virtue of the issues and contents.
He said this was a warning that was given to jurors in all cases but it was particularly acute in this case.
Judge Hunt said the video material was not being shown to blacken anyone or to make anyone look bad.
He said the jurors were required to be objective and this was evidence they had to weigh up in determining the issues.
He said they must adopt an "antiseptic" approach, difficult and all as it is. He asked them to really bear that in mind.
"You are required to put feelings and emotions to one side, and look at it as information pertaining to the decision you have to make," he said.
In her evidence about material found on external hard drives recovered from Mr Dwyer's home, Det Gda Wallace said she found 38 movie files in unallocated space on a hard drive.
This meant they had been deleted from the drive but could still be recovered.
She said two of these files were self made videos of Mr Dwyer.
There were 35 in which women were present.
