The guidelines recommended that multiple murderers (who murder two or more people) whose crimes involved sexual abuse, pre-planning, abduction or terrorism should never be released from prison. Such a sentence is known as a "whole life order". The murder of a single child following abduction, sexual or sadistic conduct also qualifies, as does the murder of a police or prison officer during the course of their duty (since 2015) and murder committed to advance a political, religious or ideological cause - along with any murder which was committed by someone who had previously been convicted of murder. Other multiple murders (two or more) should carry a recommended minimum of 30 years as a starting point sentence prior to consideration of additional aggravating factors and of any mitigating factors.