Judges remain independent individuals who have the power to use discretion, based on the differing circumstances of each case they hear when sentencing.
Maximum and minimum sentences for some offences in the UK are set down by legislation.
There are no upper or lower limits to guide the judge, although case law and previous appeal rulings on sentences will inform future cases.
Factors for the Judge to consider when assign sentence:
The crime
Intention and state of mind of offender
Consequences of the crime
Mitigation
Guilty plea
Remorse
Previous "good character"
Legislative and other guidelines
Legal precedents
In England and Wales it is the Attorney General who has the power, with the leave of the Court of Appeal, to try to increase "unduly lenient" sentences.
"The judge's task is to impose such punishment as is appropriate for the crime committed in all the circumstances."
“It is not the function of the sentencing judge to attempt to construct an equation between the value of a human life and a period of months or years in custody”
Lord Bingham of Cornhill
Three objectives of the Criminal Justice System
Punish
Deter
Rehabilitate

