However, there were two degrees of murder between 19, one carrying the death penalty and one life imprisonment, and there have recently been plans to introduce such a definition.Life imprisonment is only applicable to defendants aged 21 or over.
In some exceptionally grave cases, however, a judge may order that a life sentence should mean life by making a "whole life order." Murder has carried a mandatory life sentence in England and Wales since capital punishment was suspended in 1965.
There is currently no "first degree" or "second degree" murder definition.
Many other life prisoners have received minimum terms which, due to their great length or the fact that the killer was middle aged or elderly when convicted, make it almost certain that they will never be released.
A prisoner who has served their minimum term becomes eligible for parole.
Formerly, the Home Secretary reserved the right to set the "tariff" or minimum length of term for prisoners sentenced to life imprisonment.
However, in November 2000 politicians were stripped of this power in relation to defendants aged under 18, following an appeal to the European Court of Human Rights by the murderers of James Bulger.Inevitably, there have been numerous departures from these guidelines since they were first put into practice.For example, the judge who sentenced American fugitive David Bieber for the murder of a police officer said that he should never be released from prison, whereas statutory guidelines recommended a 30-year minimum for this type of murder - this was a decade before the act was amended to include the murder of a police officer in the course of duty as one of the offenders whose life sentences should mean life.Angus Sinclair, who had been imprisoned since 1982 for child abuse, was jailed for a minimum of 37 years in 2015.This means he will almost certainly die in prison as he was 69 by the time of his conviction for murdering two teenage girls in 1977.These were for defendants whose crimes were not serious enough to merit a normal life sentence, but who were considered a danger to the public and so should not be released until the Parole Board had decided that they no longer represented a risk.