The jury in the Graham Dwyer murder trial has been hearing details of text messages he is alleged to have sent to Elaine O'Hara from a secret phone.

In one exchange from April 2011, the man texts the childcare worker ''I preferred it when you let me put my knife in you'', ''killing is my new goal'' and ''I can and will have it all''.

The jury heard details of hundreds of text messages sent between Elaine O'Hara's iphone and a pre-paid phone the prosecution claims was owned by Graham Dwyer.

Contact began on March 25th 2011 from the man who describes himself as an old friend she used to play together with called David.

In the weeks that followed the pair would send each other numerous texts about bondage and stabbing including one where he says his urge to rape, kill and stab is huge.

In early April he sends messages about putting her in a suitcase and driving her to the woods for fun and burial.

At one point she tells him he is 'sick very sick'. Later he says he 'can and will have it all'.

Graham Dwyer of Kerrymount Close, Foxrock denies murdering the childcare worker at Killakee Mountain in Dublin in August 2012.

Earlier today, the jury was shown video clips of what appears to be the architect stabbing women during sex.

For the third time in this trial, Mr Justice Tony Hunt warned the jury that upcoming evidence - this time video clips - would not be easy.

Some 11 short videos found on a hard drive at the architect's house were played.

They had names like 'bloodletting', 'first stabbing', 'after third stabbing', with most appearing to show Mr Dwyer cutting and stabbing tied up women in the stomach and chest during sex.

Sean Guerin, prosecuting, explained that in some of the videos the women's faces have been pixilated.

The second video shows the architect talking to the camera about having just knocked himself out with chloroform. He says to camera "I'm very disorientated, I'm dizzy and have very little recollection of what happened."

The jury also heard from Detective Garda Brid Wallace of the contents of a hard drive of a desktop seized by gardaí from Mr Dwyer's office, A&D Wejchert - including a written account of a woman being raped in a cave.