Paedophile Lostprophets’ frontman Ian Watkins’ heinous crimes "did not justify his killing in any way", a jury has been told.
The disgraced singer was attacked in his cell at the high-security HMP Wakefield on 11 October last year.
Leeds Crown Court has heard Rico Gedel stabbed Watkins three times with a makeshift knife, which he then passed to Samuel Dodsworth, who threw it in a bin.
Serving prisoners Gedel, 25, and Dodsworth, 44, both deny murder and possessing a knife in prison.
Giving his closing speech to jurors, prosecutor Tom Storey KC said Watkins had "done nothing whatsoever to provoke this attack in the time leading up to it".
"However heinous his crimes were, that did not justify his killing in any way," he said.
Giving his legal directions to jurors earlier, the judge, Mr Justice Hilliard, said Watkins "had committed very serious offences, yet clearly should not have lost his life in prison while serving his sentence".
"Any sympathy you might have in those circumstances cannot play any part in your deliberations," he told the jury.
The judge said jurors should not decide the case based on "sympathy or disapproval in any direction", nor should they be "concerned with the consequences of any particular verdict".
He told them they should carry out a "cool, calm, careful and impartial examination of the evidence in the case".
Mr Justice Hilliard said they should not "embark on an inquiry" into Gedel’s evidence about his time in prison, which included claims that he hated being housed with sex offenders at HMP Wakefield and had threatened to assault "any number of paedophiles" if he was not transferred.
The judge told jurors they had only heard Gedel’s side of that story, adding: "You have not heard from those who run various prisons to explain how and why they are run with the resources they have and the issues they have to deal with."
He said there was no dispute that Gedel was guilty of at least manslaughter, and it was agreed that a "deliberate, unlawfully inflicted injury caused Ian Watkins’ death".
"The prosecution must next prove Rico Gedel either intended to kill Ian Watkins or cause him really serious harm when he did it," the judge said.
Watkins was jailed for 29 years in December 2013, with a further six years on licence, after admitting a string of sex offences, including the attempted rape of a fan’s baby.
The trial continues.
