An Oxford student has admitted killing a promising young fashion designer.
Jaggs developed a serious drug habit while at university
William Jaggs, 23, stabbed Lucy Braham, 25, to death at her family home near Harrow School in north-west London in September 2006.
An Old Bailey judge accepted Jaggs' plea of guilty to manslaughter on the grounds of diminished responsibility.
Jaggs, of Harrow-on-the-Hill, was sent to Broadmoor secure hospital and was told by Mr Justice Bean "it may never be safe to release you".
Jaggs, whose father was head of design and technology at Harrow, admitted having sexual and violent hallucinations which he blamed on an LSD and cocaine habit.
Judge Bean said doctors had described Jaggs as dangerous and a grave and immediate risk to others.
"The facts you gave to them show a chilling insight into a sick mind," said the judge.
English student Jaggs had sent a girlfriend a text message saying: "I am going to see a shrink today. As you know, I am a psychopath".
Jaggs once emailed a teacher to say he was hearing voices and having hallucinations, including thinking he could hear his friends having sex.
"These are paranoid delusional nightmares brought on by drugs," he said.
He told a psychiatrist that four days before killing Miss Braham he took a chainsaw to kill a friend, but the friend was not at home.
Jaggs was initially charged with Miss Braham's murder, but he denied this charge in court on Thursday.
'Innocent and blameless'
The court heard Miss Braham was an "entirely innocent and blameless" young woman.
The property is yards from the school entrance
She was a promising fashion graduate working on her own clothing range. Her father is art director at Harrow School.
When police responded to reports of screaming at her house, officers found Jaggs naked and yelling wildly.
He began stabbing himself in the chest as Miss Braham lay in a pool of blood at his feet.
Jaggs injured himself so badly that he fell into a coma and it was several days before police could interview him.
Miss Braham had won a scholarship to Millfield School in Somerset.
Her teachers remembered her as an exemplary art scholar with a promising career ahead of her.
She later graduated from the London College of Fashion.
In a statement read out in court, the Braham family compared the way she and Jaggs had used their privileged upbringings.
She was nicknamed "the ray of sunshine" and one of her school friends referred to her "amazing smile which said everything's going to be OK".
Lucy Braham was a talented fashion student
By contrast, Jaggs "spat in the face of everyone who had given him his advantages - his parents, his teachers... and everyone who put him in a position of trust".
The statement added: "What happened to her is unspeakable.
"Through our tears of rage and distress at her ordeal we look for something to hold onto for solace and strength.
"What we find is the knowledge that we could not have loved her more and she knew this, and we know she could not have loved us more."
Mr Braham also said his daughter was "badly let down" by Harrow School which, he said, failed to tackle Jaggs' drug-taking when he was a pupil there.
In a statement, Harrow School said: "The school has been devastated by the death of Lucy and by the appalling consequences of her death for two families who contributed so much to our community over many years."