A Sheffield man who strangled his grandmother and drowned his aunt in her bath has been jailed for life.
Christopher Whelan, aged 21, of Dransfield Road, Crosspool, was ordered to serve a minimum of 15 years behind bars after arming himself with an axe and a penknife to kill his 75-year-old grandmother, Rose Hill and aunt Julie Hill, 51, after allegedly struggling against an 'irresistible impulse' to kill others.
Whelan claimed Satan directed him to kill his victims at his aunt's home in Station Road, Shirebrook, Derbyshire, on February 25 this year.
He admitted manslaughter on the grounds of diminished responsibility.
Nottingham Crown Court heard his mental health had deteriorated because of regular cannabis use.
Whelan attacked and then drowned his aunt, Julie, in her bath and strangled his grandmother, Rose, who was from St Francis Close, Crosspool.
He told a psychiatrist he had travelled to his aunt's house intending to rob her for money.
Judge, Mrs Justice Carr, said Whelans' victims endured an 'absolutely terrifying experience before they were actually killed'.
Jailing him she told Whelan his victims died in the 'most horrific circumstances'.
"I have no hesitation in concluding that you pose a significant risk to members of the public of serious harm occasioned by you of further specified offences," she said.
"Both consultant forensic psychiatrists confirm that you remain an unpredictable and dangerous person, continuing to suffer from violent urges".
A Derbyshire Police spokesman said: "Christopher Whelan admitted manslaughter on the grounds of diminished responsibility at an earlier hearing.
"He was told at Nottingham Crown Court this morning that he would serve a life sentence with a minimum tariff of 15 years.
"The 21-year-old, of Dransfield Road, Sheffield, went to the home of his 51-year-old aunt, Julie Hill, in Station Road, Shirebrook, on February 25.
"He killed Julie and then his grandmother, Rose Hill, 75, who was visiting the house. He then fled to London, where he called police."
Whelan's cousin, Liam Parker, 22, of Charnock Crescent, Charnock, Sheffield, killed himself after discovering the bodies of his mum and grandmother.
He was struck by a train at Shirebrook station in April.