A man from Norwich accused of a double murder has told a jury he feels "very guilty" and "mortified".
John Moody, 45, admits killing his ex-girlfriend Karen Brown, 39, and her new boyfriend Kenneth Snell, 65.
Their bodies were found at Mr Snell's home at Cringleford, near Norwich, in October. Both had been stabbed.
Mr Moody denies murder, claiming diminished responsibility. He told Norwich Crown Court he found some of the evidence "very upsetting".
He gave this as his reason when asked by his barrister John Farmer why he had not been in the dock throughout the trial.
He said he could not remember the killings and added: "I feel ashamed of myself and very regretful.
"I miss Karen deeply and Ken. I feel I've let a lot of people down."
Asked by Mr Farmer if he considers the victim's families, he replied: "I think about it all the time.
"I feel very remorseful, very guilty and mortified."
Mr Moody, of Kerrison Avenue, had been in a 12-year relationship with Ms Brown and ran a sandwich shop with her in the city centre.
Describing Ms Brown as the love of his life, he said he could not remember hitting her at the end of their relationship in 2008.
Ms Brown's father, Peter, told the jury last week that his daughter claimed Mr Moody had hit her and tried to strangle her, prompting her to move in with her parents.
The prosecution claim he murdered her and Mr Snell on 31 October within hours of learning that they were together.
On Monday the jury heard from psychiatrist Dr Simon Wood, called by the prosecution, who concluded that Mr Moody did not have a psychiatric condition.
In evidence given last week by Dr Alan Smith, a psychiatrist for the defence, the doctor said the defendant was suffering from an abnormality of the mind and was in a depressive state.
The court has heard recordings of Mr Snell's and Ms Brown's 999 calls as they were attacked at his Brettingham Avenue home.
Post-mortem examinations showed Ms Brown sustained 13 stab wounds and 31 other injuries.
Mr Snell sustained seven stab wounds and 38 other injuries.
The case continues.