Convicted murderer David Norbert Schembri may have flung the words "I'm still alive" in the direction of his former girlfriend's family to rub salt into their never-to-be-closed wounds, but the kind of life he has embarked upon behind bars is not likely to be one worth living.

There will no doubt be times, in fact, when he wishes that what he said as he exited court last Thursday turns out to be palpably untrue. Then he will realise he will have to face another day. And another after that. This reality has always been one of the strongest arguments against capital punishment.

The victim's father seemed to recognise this, rising above the jibes - despite the pain he must have felt since his daughter was brutally killed in front of her seven-year-old child almost five years ago - to say, simply but admirably, that justice had been done.

Mr Justice Joseph Galea Debono played a commendable part in the process, by condemning Mr Schembri to life imprisonment - just the ninth such sentence in the past 20 years. This was fully justified given that, as the prosecuting officer said, this was a case of "extreme cruelty" and "something rarely witnessed in these courts". Apart from that, the defendant had 12 previous convictions, three of which had carried jail terms. Reforming such a character is not even a remote possibility.

But beyond the facts of this particular case Mr Justice Galea Debono made a point which cannot be ignored: that this murder could have been avoided if, eight days before, the courts had converted Mr Schembri's probation, in relation to another serious offence, to a prison sentence.

In the more modern world of sentencing, there is a growing tendency to see the reason behind not sending criminals to, or not keeping them in, jail - such as fewer offenders returning to crime; saving taxpayers' money by not funding their stay in prison; giving them more chance of rehabilitation by thrusting them back into the community.

But, as Mr Justice Galea Debono noted, Mr Schembri's probation officer had testified at the time that the defendant was threatening his wife and - he was a drug user - still testing positive for cocaine. In addition to this, it was known that he had tried to flee Malta after committing an offence that eventually led to him being sentenced to 23 months in jail. In other words, there were clear signs that he was not the type of criminal that should be permitted to walk the streets.

It is rare for a judge to make a statement that is critical of the justice process that was administered by others, but Mr Justice Galea Debono said: "Had things not been done this way, this heinous crime, only eight days later, could have been avoided and Josette Scicluna would have continued to enjoy her life with her daughter."

We all know that this did not turn out to be the case. What we need to do next is establish why. How was a man with a string of convictions and a history of violence allowed to roam freely when he could have been put in jail? An inquiry should be held to find out, as well as to suggest how we can avoid this situation happening again. And if there were mistakes, the people who made them should be held accountable.