Jeremy Bamber, serving life for killing five members of his family in 1985, must never be released from prison, a judge decided today.
"These murders were exceptionally serious," said Mr Justice Tugendhat after reviewing Bamber's whole-life tariff.
In a written decision to be communicated to Bamber, who had asked for a specific minimum term to be set to give him some hope of parole, the judge said: "In my judgment, you ought to spend the whole of the rest of your life in prison, and I so order."
Bamber, now 47, who continues to maintain his innocence, was found guilty of shooting his wealthy adoptive parents, June and Nevill, his sister Sheila Caffell, and her six-year-old twin sons Daniel and Nicholas at their farmhouse in Tolleshunt D'Arcy, Essex, in August 1985.
The prosecution alleged he had murdered them out of greed, hoping to inherit a £500,000 fortune.
But Bamber consistently argued that his sister, a model known as Bambi, who had a history of mental illness, killed her family before turning the gun, a .22 semi-automatic rifle, on herself.
In October 1986 Bamber was convicted by a majority of 10 to two of the murders.
He was sentenced to life with a recommendation by the trial judge that he should serve a minimum of 25 years.
But he was later told by the Home Secretary and the Lord Chief Justice that in his case life must mean life.
Bamber has twice lost appeals against conviction.
Today the judge said he had read submissions from Bamber's solicitors pointing out that he was not suffering from mental illness and was behaving and progressing well in prison.
He had also read victim impact statements from the next of kin of the deceased.