By Danny Shaw
Home affairs correspondent, BBC News
Some of the laws on murder have been in place since the 17th Century
Four years ago, the Law Commission, which advises the government on legal reforms, reported its conclusions on the law on homicide in England and Wales.
"It's a mess," the commission said.
Its findings were based on discussions with people involved in the criminal justice system, that had demonstrated the "breadth and depth of discontent" with the current arrangements.
A year later, another Law Commission review said the homicide law was a "rickety structure set upon shaky foundations".
Some of the rules had been in place since the 17th Century, the commission said, other rules were uncertain or constantly changing, creating a situation where the law could not be stated with "clarity or certainty".
It recommended a new Homicide Act, to replace the 1957 version, which would bring together all the relevant case law.
In a further review, published in 2006, the commission suggested a three-tier system for homicide cases, depending on their seriousness.
These were first-degree murder, carrying a mandatory life sentence; second-degree murder, with a life term at the discretion of the judge plus sentence guidelines; and manslaughter, also with a maximum penalty of life.
So what had prompted the Law Commission to look into the troubled question of murder legislation and come up with such a radical blueprint for reform?
The answer may have some relevance for those considering whether or not the latest government proposals will work.
What had prompted the commission's extensive review was turning the spotlight on the partial legal defence of "provocation" - just the issue the government is now tackling.
The commission said, in 2004, that changes to the "provocation" rules were unlikely to work without fundamental reform to the murder laws.
And so it ploughed on with a wholesale review of homicide legislation.
The government, on the other hand, after reading the Law Commission's reports carefully, has decided to do it differently.
No grand shake-up, no bonfire of legislation, no radical restructuring.
Instead, it's taking the murder reforms step by complex step, with new rules on provocation and some technical, and relatively uncontroversial, adjustments to the law on diminished responsibility, complicity and infanticide.
The thinking behind it is that ministers will have more support for these measures, than they would for a shake-up involving a graded system of murders, which could see an end to the mandatory life sentence in some cases.
That may prove to be true. But the danger that the Law Commission and other experts have identified remains.
That is that the offence of "murder", under current law, encompasses such a wide variety of scenarios, from mercy killings to serial murders, from crimes of passion to contract killings, that it is a recipe for confusion and injustice in the courts.