A man who killed his parents in an attack described by a detective as "the most brutal, unprovoked" killing he had ever seen has been jailed for life.
Kamil Dantes, 29, stabbed his disabled father Leszek Dantes and mother Malgorzata in Worksop, Nottinghamshire.
His parents, both aged 54, were found dead in their bedroom on 21 April 2014.
Dantes, originally from Poland, admitted manslaughter on the grounds of diminished responsibility and was jailed for 19 years.
He was sectioned under the Mental Health Act and was ordered to serve his sentence in a high security hospital after pleading guilty at Nottingham Crown Court.
His father, who walked with a frame following brain surgery in 2010, had more than 20 stab wounds and his mother between 25 and 30, the court heard.
The attack was so severe the tip of one of the knives became lodged in Mrs Dantes's head.
Det Ch Insp Leigh Sanders said it was one of the "most brutal, unprovoked" attacks that he had ever come across in his career.
"The severity of the attacks is something I have not experienced before, nor have many others in the criminal justice system," he said.
Mr Justice Haddon-Cave said Dantes had an "abnormality of mental functioning".
He added: "Your deteriorating mental health had much to do with your history of drug use and in particular your cannabis habit.
"This is another example of the danger of cannabis use and its ability to induce psychotic behaviour in young men."
Dantes was a regular user of cannabis and had smoked the drug for 12 years as well as taking amphetamines, the court heard.
He said the attack was "the biggest mistake of my life".
Mr Justice Haddon-Cave said: "You will remain an ever present serious threat to others, in particular members of your family."