A County Durham man accused of killing his parents for a £230,000 inheritance has angrily denied that he considered killing his "disabled" nephew, a court has heard.
Stephen Seddon told a jury that he drove from his home in Seaham to Carrington, near Manchester, to deliver a holdall of drugs in return for cash.
He maintained he returned straight home and did not visit parents Bob and Patricia on 4 July last year, the court heard.
Seddon is accused of shooting his parents dead at close range with a sawn-off shotgun at their address in Sale, Greater Manchester, after he failed in an attempt to kill them four months earlier when he drove into a canal with them aboard.
Giving evidence, Seddon denied that as part of his plot he considered shooting his 17-year-old nephew Daniel.
Cross examining Seddon, Peter Wright QC, for the prosecution, said he had telephoned his parent's house beforehand to check whether he needed another shot-gun cartridge "for Daniel".
Seddon responded: "That's a sick thing to say about a disabled child. You are sick."
Mr Wright said his nephew was also in the BMW which went into the canal.
Seddon denies two counts of murder and two counts of attempted murder.
The court has heard that Mr and Mrs Seddon spent their retirement in a "normal suburban avenue in a quiet suburban part of south Manchester".
They enjoyed a "modest but comfortable" life, with Mr Seddon getting an occupational pension from British Airways and Mrs Seddon her state pension.
Tragedy struck the family in September 2008 when their daughter, Lesley, died at the age of 40, leaving her parents to look after her son, Daniel, who lived with them at the family property.
The couple made a will in October 2009, naming each other as beneficiary if one of them died, with their assets valued at #356,000 and, after liabilities, an estate worth #230,000.
But if they both died, Stephen Seddon "got the lot", the court heard.
"That's why they both had to die," Mr Wright said when he opened the prosecution's case.
Seddon has denied murdering or attempting to murder his parents and repeatedly said he would "never hurt them".
Today he denied making up a "cock and bull story" and attempting to leave a "false trail" for police to follow.
His barrister Toby Hedworth QC said he was "plainly given a great deal of financial assistance" by his parents.
Seddon was accused of laying a false trail by staging the murders to make it look as if his father had shot his mother before killing himself.
Mr Wright said that no assassin would need to stage a false suicide if they were carrying out a gangland execution.
The only reason would be to take attention away from the person responsible," he suggested.
The case for the defence ended today and summing up speeches are expected to begin on Wednesday morning.