A jury in the trial of a Norfolk man accused of a double murder has heard closing statements from the defence and prosecution at Norwich Crown Court.
John Moody, 45, of Norwich, denies murdering Kenneth Snell and Karen Brown but admits manslaughter on the grounds of diminished responsibility.
The prosecution claim their deaths were caused by "an angry and jealous man".
But the defence urged jurors to accept Moody was suffering from an abnormality of the mind.
Abnormality of mind
John Farmer, defending, there was no other explanation than that Mr Moody's abnormality substantially impaired his responsibility of his actions.
Prosecuting, Graham Parkins QC told the jury that there was a "dark side" to Mr Moody, that behind closed doors there was violence and intimidation against Karen Brown.
Miss Brown, 39, and Kenneth Snell, 65, were found dead at Mr Snell's home in Cringleford, near Norwich, in October.
They had suffered multiple stab wounds.
Mr Moody and Ms Brown, who had been in a 12-year relationship which ended in 2008, had run the sandwich shop Baguette Express near Norwich Market.
The prosecution claims Mr Moody murdered Ms Brown and her new partner, Mr Snell, after being told of their relationship earlier that day.
The trial continues.