Ministers have set out details of a review of the murder laws in England and Wales - which could see changes in the legal definition of offences.
Lord Woolf backs the Home Office review of murder sentencing
The Home Office announced the review last October. It is the first major reassessment of the laws in 50 years.
Stating its terms, Home Office minister Fiona MacTaggart said: "It is vital that the law on murder makes sense."
Currently all those convicted of murder must receive a life sentence but judges recommend a minimum term or "tariff".
Ms MacTaggart said the government remained committed to retaining mandatory life sentences.
"Murder is the most serious crime and it is essential that the law reflects this."
But she added: "The review will look at the overall framework of murder to ensure that the government provides coherent and clear offences which protect the public and enable those convicted to be appropriately punished."
"It is vital that the law on murder makes sense and people clearly understand it."
Other elements of murder, including the issue of provocation, will also be considered in the Home Office-led review. Raising the defence of provocation, for example due to infidelity, can allow defendants to plead manslaughter instead of murder.
It will also look at the level of force allowed to defend property.
Law Commission review
The decision to hold a review followed research from the independent Law Commission, which advises ministers on changes to the law, in August.
The research said that legislation governing murder was "a mess".
It revealed that 64 respondents out of 146 - including 21 judges - believed a mandatory life sentence for every case of murder was "indefensible and should cease".
Ken Macdonald QC, the Director of Public Prosecutions, has backed the introduction of a system that recognises degrees of homicide.
Under the current tariff system, people convicted of "mercy killings" tend to receive lower recommended terms than those who have killed a random stranger, for example.
In May, the most senior judge in England and Wales, Lord Woolf, said he opposed Parliament passing laws that forced judges to impose particular sentences.
He supported the Home Office's decision to launch a review, saying: "I'm not in favour of mandatory sentences full stop."
The Criminal Justice Act 2003, which applies to offences committed from 4 April this year, requires courts to impose mandatory sentences on any of 155 offences under certain circumstances.
The review is also expected to look at the level of force householders can use to defend their property.
It is the first major reassessment of the murder laws since the Royal Commission on Capital Punishment from 1949 to 1953, which led to the Homicide Act in 1957.
The review will be independent of ministers and is expected to last 18 months.