Inspector Paul Sheridan, in charge of operation Lorimer. Credit:Sebastian Costanzo While she remains a passionate advocate for victims' rights, she believes we should explore non-jail options as well. Usually those who don't automatically call for longer jail terms are categorised as latte-sipping lefties who should get into the real world, but no one can doubt her tragic pedigree. It was 19 years ago when a trap door opened on Carmel's life, plunging her into the criminal justice system. On August 15, 1998, her husband, Senior Constable Rod Miller, and Sergeant Gary Silk were shot dead in Cochranes Road, Moorabbin, while on a stakeout trying to identify two bandits who had raided a series of suburban restaurants. It would take two years before the killers, Bandali Debs and Jason Roberts, were charged and another two before they were convicted. Carmel saw the flaws in the system first hand and a few years later decided to use her experience to improve it after re-reading her victim impact statement that said, "I don't want anyone to have to live through what I have." In 2004 she was appointed a founding member of the Sentencing Advisory Council and in 2008 to the Adult Parole Board. "I believed in locking them up and throwing away the key and mandatory sentences for top-end violent crimes such as rape and murder."

Carmel Arthur and Rodney Miller. In fact she is the only surviving member of the "old" Parole Board, a body wickedly under-resourced that was pilloried after it was revealed that Adrian Ernest Bayley – the man who in 2012 murdered Jill Meagher – should have been in jail at the time with his parole cancelled when he was convicted of another violent assault. Since then parole has been turned on its ear. Consider this: in 2013-14 a total of 60 parolees were convicted of serious violent offences, the following year it was 22 and the next 13. This year it will be single figures. While the number of prisoners has gone up the number of parolees has reduced from 1700 to 900. Carmel Arthur, wife of slain policeman Rodney Miller. Credit:Mario Borg According to Parole Board chairman Judge Peter Couzens, one of the major changes has been that prisoners must apply for parole rather than receive automatic hearings. This means, he says, the inmate has to prepare for release by completing appropriate prison courses that lower the risk of reoffending.

He says more stringent supervision, better communication between police, prisons and the board, GPS and alcohol-detecting electronic bracelets, immediate intervention on parole breaches and a rule that puts community safety first have improved the system markedly. Carmel Arthur and her son James Miller. Credit:Jerry Galea I once saw parole as a sentence discount now I see it as an insurance policy for the community. It is a much safer option than to be released without support - some people need to be constantly monitored. Carmel Arthur But it will always remain an inexact science. According to Carmel, "Parole is predicting human behaviour and you can't." Or as one former board member admitted, every time he read of a violent crime, "I would pray it wasn't one of mine" – an offender he had released on parole.

Carmel Arthur outside the Supreme Court after the sentencing of police killers Bandali Debs and Jason Roberts. While there is always a risk, parole is a vital part of the system. Of Victoria's 7121 prisoners, all but a handful will one day be released. And those who are supervised are less likely to reoffend. "I once saw parole as a sentence discount. Now I see it as an insurance policy for the community. It is a much safer option than to be released without support – some people need to be constantly monitored," Carmel says. Ian Silk with Carmel Arthur and Val and Peter Silk behind. No wonder Shawshank Redemption remains one of her favourite movies – "Who didn't want Morgan Freeman to be released?"

When she started to try to change the system, she saw how victims were left to watch helplessly as the court process swirled around them without explanation. The family of one murder victim was threatened with expulsion when they asked questions about the evidence presented to the jury. Convicted police killer Jason Roberts is led into court by security. Credit:Vince Caligiuri "For too long victims were the forgotten parties. The system is getting better but there is a way to go." And remarkably she includes as victims the families of some offenders who are left devastated by their relatives committing repulsive crimes. One of her ideas that makes too much sense to ignore is for judges in serious crimes to call victims into their chambers to privately explain the sentence they are about to publicly deliver.

Bandali Debs is led into the court by security. Credit:Vince Caligiuri "You may not like it, but if it is explained to you then it is easier to accept." In the Silk-Miller murder trial she was initially floored when a key piece of evidence was withheld from the jury. Debs, who knew the police taskforce was concentrating on the theory that the killers were the eastern suburban restaurant bandits, hatched several plans to send investigators in another direction. Bandali Debs arriving at the Supreme Court in February 2003. Credit:Joe Armao In the most cold-blooded plan he was recorded contemplating killing Carmel and baby James, saying, "Seriously. Do you think I should get rid of the kid and the mother? ... So they try and get the investigation to think that it's drug related or anything like that."

Carmel recalls, "I was shocked when evidence of the threat to Jimmy and me was thrown out" until prosecutor Jeremy Rapke, QC, and the head of the Lorimer taskforce, Paul Sheridan, explained they had sufficient evidence to convict and the Debs tape could provide grounds for appeal. Sergeant Gary Silk. If she thought the 2002 conviction of Debs and Roberts would finalise the court process she was wrong. There were appeals and then three years ago Roberts started to agitate for a new trial claiming he was not with Debs that night, who he declared acted alone. This was despite the dying Rod Miller telling police there were two offenders and forensic evidence that there were two murder weapons. At the trial the prosecution called nearly 200 witnesses and the defence only four with Roberts choosing to stay silent. Roberts' team put a submission to Attorney-General Martin Pakula that there had been a miscarriage of justice and their client deserved a retrial because of new and compelling evidence (when really it was a case of trying to have a second bite of the cherry). Earlier this year the Attorney-General rejected the submission.

For the relatives of the murdered police the three years it took to reject Roberts' bid for a retrial have been hell and Carmel felt it was a direct attack on the honesty of the Lorimer taskforce and officer in charge Sheridan. "You couldn't find a man with greater integrity than Paul." Debs was sentenced to life in prison (he has since been convicted of a further two murders) and Roberts life with a 35-year minimum. But Roberts will now serve life as the government last year passed retrospective legislation banning parole for police killers. Here Roberts has an unlikely ally – Carmel Arthur, who while she won't speak of the specific case, says, "I'm not a fan of retrospective legislation. We should be able to trust the system so that what you see is what you get. We need to know the sentence with clarity." Which means she would have been happy for Roberts to be paroled if he showed real remorse and was properly supervised. Crime makes us angry and frightened. We want offenders punished, victims helped and the rest of us protected. And it is true there are some hard-core offenders that will never change and should remain in custody.

But people like Carmel Arthur say we also have to deal with the drivers of crime, such as drug abuse, mental illness and homelessness – none of which are vote winners. When governments announce expensive drug rehabilitation programs, newspapers delegate the stories to sit near the gardening column. When they announce tough sentencing laws they are on page one. "Most people are not directly impacted by crime but most people know someone impacted by drugs. There are great families whose kids become involved in drugs and they don't know what to do," Carmel says. Away from the justice system, Carmel works as an asset planning manager for the police and went on to marry Gary Silk's brother, Peter – a cracking bloke who along with third brother Ian is a slightly demented Hawthorn supporter. And James? He is almost 19 and making his way in the building trade with one eye on becoming a policeman like his old man.

Bandali Debs and Jason Roberts may have robbed Carmel of the life she planned but they could not destroy her sense of decency. While they will forever be defined by their act of bastardry she will not. And if she is brave enough to question the lock 'em up at all cost mentality, shouldn't we all?