Robbie McIntosh may never be released from jail after he was handed a lifelong restriction order for battering Linda McDonald in Dundee. McIntosh was on unsupervised “home leave” at the time - before any parole board had assessed his case.
Ms Sturgeon pledged that “lessons will be learned” from the case and expressed her sympathy for Mrs McDonald and her family.
At First Minister’s Questions today, Ms Davidson said: “I don’t think it’s unreasonable for the public to expect prisoners to serve their time.
“When a case like this emerges the question from the public is why again? Why is a killer let loose to try and kill again?
“Why are the dice loaded against victims and in favour of criminals again? Why do we only act when another family is left to pick up the pieces of their lives again?”
McIntosh, 32, who was jailed for life in 2002 for stabbing a dog walker to death on Dundee Law when he was 15, was granted home leave before having appeared before the parole board to assess whether he was suitable for release.
Ms Davidson said that last year there were some 4,000 prisoners granted temporary leave from prison before their case had been considered by the Parole Board.
“This appalling case raises further questions about our justice system, and why killers who should be in jail are instead allowed to walk free before a parole board has even ruled that they are safe to do so,” she added.
A review of the case has already been carried out by the Scottish Prison Service and this will form part of a wider investigation by the Multi Agency Public Protection Arrangements (MAPPA) which manages the release of serious offenders in Scotland.
The First Minister said a review of the facts surrounding the case has been undertaken by the authorities and told MSPs “lessons must be learned”.
She added that the case was “extremely distressing” and that she could “entirely understand and sympathise with the views of the family”.
Ms Sturgeon said: “A rigorous risk assessment is undertaken by the Scottish Prison Service before any offender is granted any form of unescorted leave, that involves psychological assessments, social work reports, and reports on the time they have spend in prison.
“Home leave is also always granted with very strict conditions applied.”
However she added that home leave is an important part of Scotland’s penal system to ensure prisoners being released after long sentences can be successfully re-integrated into society.
Ms Sturgeon added: “I think at the heart of Ruth Davidson’s question, as is often the case with the Conservatives - although often their actions in government don’t quite match their rhetoric in opposition - is this notion that somehow Scotland’s justice system is soft touch.
“Frankly the facts do not bear that out. We have one of the highest prison populations in the whole of Europe and one of the big challenges for our criminal justice system - of course serious criminals should be locked up that’s not in doubt - but the bigger challenge is how we rehabilitate these prisoners so there’s less chance of reoffending.”
She said lessons that could be learned from the case could include changes to “tighten the way in which risk assessments are carried out in future”.
The Scottish Prison Service has already conducted a review into the McIntosh case.
An SPS spokesman said: “All of us take very seriously the responsibilities that we’ve got. There isn’t anything that I or anyone in SPS can say that takes away the trauma of the absolute horror that that poor woman has had to experience because of the despicable actions of an individual.
“If there’s anything we can learn from it we will learn from it.”
He insisted that Scotland has a “rigorous” criteria in place to determine whether prisoners can be granted home leave.
“There are probably about a third as many people in open conditions as was the case 20 years ago,” the spokesman went on.
“The criteria that people have to go through to make that progress means that they’re almost entirely long-term prisoners that we’ve had with us for a while and who have been subject to a series of assessments going on over a number of years before they get to that stage.”
But he said the “testing” of offenders in the community through home leave happens before parole because it is a “fundamental part” of the consideration for any board.
“The parole board would have an expectation that we would test them,” he said
A critical incident review has been conducted by the prison service and this will now feed into the serious incident review which is being carried out by MAPPA.
But prison chiefs say that during the 2016/17 financial year there were 19,000 days of home leave for Scottish prisoners while there were only 27 occasions when there was a revocation of an offender’s licence for “breach of conditions.”