Alexander Bamford, 34, of Reading, Berkshire, denies attempting to murder his wife Diane; murdering her father, Ronald Brown; wounding Irene Brown; attempted grievous bodily harm on Michael Gibbons; and aggravated burglary.
Yesterday, at Reading Crown Court, Jeffrey Burke, for the prosecution, took the unusual step of outlining part of the defence case during his opening speeches.
Mr Bamford is to say that he had none of the usual warning signs that would have allowed him to prevent the condition, which left him unaware of his actions, because he had been switched from animal to genetically engineered insulin in 1987.
But Mr Burke said that tests taken immediately after he was arrested in the early hours of 7 July 1991 showed he could not have been suffering from hypoglycaemia.
Mr Burke told the court that in March 1991, Mrs Bamford had gone with their three children to a women's refuge after Mr Bamford had threatened her with a knife, following years of violence which had often happened after he had been drinking.
Mr Burke said that Mr Bamford, an unemployed bricklayer, spent Saturday, 6 July with friends at a pub and then telephoned his wife at her parents' house where she was staying. He became abusive and threatening.
The court was told that he set off for the house in the Whitley Wood area of Reading, but first went to his flat to pick up the 6-inch boning knife. Mrs Brown saw him arriving from an upstairs window and refused to answer the door, but he broke a kitchen window and climbed through.
Mr Burke said that after attacking Mrs Brown, Mr Bamford stabbed Mr Brown, who died almost immediately. He then turned on Mrs Bamford. He was finally confronted by Mr Gibbons, the husband of the Brown's eldest daughter, who fought him off with an iron bar.
When police arrested Mr Bamford 15 minutes later he had injected himself with eight syringes of insulin.
Mr Burke said that hospital tests taken on Mr Bamford's blood sugar levels showed that he could not have been suffering hypoglycaemia during the attack. But, he said, Mr Bamford would still seek to say the condition had been brought on by switching from animal insulin to human or genetically engineered insulin. Mr Burke said: 'He says that after that he could not control his swings of mood and became violent. It will be said that he had a severe hypoglycaemic episode and was not capable of controlling his body as a result of the rapidity and lack of warning with the human insulin.'
Mr Burke rejected this. He said this was a case of a man with a history of violence who was angry, had been drinking and who armed himself with a knife and went to the house with the intention of using it.