Graham Dwyer's trial has heard he told Gardaí 'I did not murder Elaine O'Hara' following his arrest in October 2013.
The architect of Kerrymount Close, Foxrock is alleged to have stabbed the childcare worker to death at Killakee Mountain in Dublin.
Det Sgt Peter Woods has told the jury he arrested Graham Dwyer on suspicion of murdering Elaine O'Hara at his Foxrock home just after 7am.
He cautioned the architect who replied 'I don't know what you're talking about'.
He was then brought to Blackrock Garda station in a patrol car.
In his first interview detectives asked Graham Dwyer if he knew Elaine O’Hara his reply – the first of many denials – was 'I didn't kill anybody'.
He said he followed the case in the newspapers and online but didn't retain the details.
The accused repeatedly asked why he was being questioned and expressed concern he'd lose his wife and that his name and picture would be all over the media.
In his second interview he asked why is his life being ruined and told detectives 'I did not murder Elaine O'Hara'.
