A New South Wales Government plan to make life sentences compulsory for people who murder police officers has worried the state's former director of public prosecutions and civil liberties advocates.
The Government will this week introduce legislation that says anyone convicted of murdering a police officer would automatically be sentenced to life in jail. At the moment there are mandatory 25-year sentences for people convicted of murdering police officers or other public officials.
Australian police unions have welcomed the move, saying officers in other states should get the same protection.
But the former NSW director of public prosecutions, Nicholas Cowdery QC, says there is no evidence this will deter criminals and that it takes away courts' independence.
"This kind of offence [is] going to be committed in the heat of the moment in an atmosphere of great drama and tension," he said.
"People aren't going to stop and think, 'oh dear, if I do this and if I'm caught and if these circumstances are satisfied I will end up with a life sentence, I'd better not to do it'."
Brett Collins, spokesman for civil rights group Justice Action, agrees the move will not work.
"You wouldn't save a single policeman," he said.
"To suggest that people wouldn't be killing policemen because they would think carefully beforehand and think 'oh I've got a mandatory life sentence' is not what happens."
Mr Collins says judges should be free to sentence as they see fit. He says the murder of officers does not happen often, but when it does it tends to be harshly dealt with by the judiciary.
"This is putting wrong values on the values of life. The values of life, of course every person's life, is a sacred thing," he said.
"And to suggest a policeman's life is of more value than another public servant's or someone else who is very vulnerable is wrong."
The Australian Lawyers Alliance says mandatory life sentencing has not acted as a deterrent to police killings overseas. Its director Greg Barns says he will be writing to NSW Attorney-General Greg Smith over the lack of discretion for the courts.
"Mr O'Farrell has said that this will act a deterrence. It has proved to be no deterrence in the United States where mandatory life sentences for police killers has been in place since the 1970s," he said.
The legislation will be introduced into NSW Parliament this week. The move has been a long-time promise by new Police Minister Mike Gallagher. Mr Gallagher was once a police officer himself and had made a pledge to the families of several police officers who have been murdered that the existing sentence would in future cases become life.
"I was first introduced to the pain and trauma of a police officer being murdered when I was in fact a trainee at the police academy back in 1980," he said.
"At that one moment in time we were all drawn together in terms of the impact that this had on the police family and the wider community."
If passed, a mandatory life sentence will not apply to cases of manslaughter. Mr Gallagher says it is only for those found guilty of murder where the victim is an officer performing his duty and where the murderer knew or ought to have known the victim was a member of the force.
The plan has been welcomed by the state's Police Association, whose president is Scott Weber.
"When everyone else is running away, police officers are running in," he said.
"This puts us in harm way all the time and that's why this legislation is so necessary for police as a start."
Mr Weber says a law of this kind would be a huge morale boost for police officers.
"If it actually just stops one police officer being seriously injured or killed, well then the legislation's worth its weight in gold," he said.
Ian Leavers, the president of Queensland's Police Union, says if the law is passed in NSW, police in other states should be entitled to the same protection.
"When it comes to serious assaults against police, and now murder, other states are leading the way and their tough sentencing regimes are leaving Queensland well and truly behind," he said.
"I think time has come where governments have not only got to protect emergency services workers but ensure that sentences meet community expectations."