A man released from prison by mistake is to be detained indefinitely in the secure mental health unit at Broadmoor for stabbing a man to death on a bus.
Paranoid schizophrenic Anthony Joseph, 23, admitted the manslaughter of Richard Whelan, 28, who tried to stop him throwing chips at his girlfriend.
Mr Whelan was stabbed seven times in Holloway, north London, in July 2005.
The government has launched an inquiry after it emerged Joseph should have been in custody at the time.
Sentencing him Mr Justice Gross said: "The circumstances of this case are tragic indeed.
"They form the nightmare of all those who use public transport."
In a statement, Mr Whelan's family said they were still trying come to terms with the "manner of his death" which felt like a "physical blow".
They said his death had left his 73-year-old father "devastated", as the pair had lived together since Richard's mother died when he was 12.
"It is beyond belief to us that the defendant killed Richard without a moment's hesitation or second thought," the statement said.
"We miss Richard every day, our lives have changed forever and we know that nothing will ever be the same again, he will always be missing."
'Angry and vindictive'
Joseph, from Islington, had been released from prison in Manchester after a sex allegation was dropped but should have been detained to face charges relating to a burglary offence.
After a second jury failed to reach a verdict the prosecution accepted Joseph's manslaughter plea on the grounds of diminished responsibility.
The judge praised Mr Whelan for standing up to Joseph saying: "Mr Whelan was not content to stand for this behaviour. His reaction was entirely understandable and, for that matter, praiseworthy."
Speaking to Joseph, Mr Justice Gross said his behaviour was "angry and vindictive" and said he took his anger out on Mr Whelan.
Stressing that Joseph should be held under maximum security the judge said: "You should not have been released at all.
"You bear considerable responsibility for your actions which were fuelled by alcohol and crack cocaine," he said.
Prosecution said the re-trial in November centred on Joseph's mental health at the time of the attack.
The defence said their client was suffering from the onset of schizophrenia.
He was retried after a previous jury failed to reach a verdict in May.
Following the verdict last month Mr Whelan's family said they were "very disappointed" and would have liked to see Joseph convicted of murder.
Mr Whelan was with his girlfriend, Kerry Barker, 38, on the top deck of the number 43 bus when the incident occurred in July 2005.
CCTV footage showed him struggling with Joseph shortly after he threw chips at Ms Barker and another woman.
Mr Whelan was stabbed through the heart and had six other stab wounds.