 Although murder carries a mandatory life sentence, it rarely means that the offender will spend the rest of their natural life in prison.A "minimum term" is usually set by the judge to indicate the period the offender must serve in custody before being released on licence.The relevant provisions are contained in the Criminal Justice Act 2003 It gives judges a clear starting point for the minimum period to be considered, ranging from a "whole-life" term down to 12 years.