I remind members of my entry in the register of members’ interests; my wife is a sergeant with Police Scotland.

November will mark 20 years since Alistair Wilson was murdered on the doorstep of his home in Nairn. In two decades, his killer has never been caught. Alistair’s family have spoken with The Press and Journal and raised serious concerns about Police Scotland and Chief Constable Jo Farrell.

Andrew Wilson was four when his father was murdered. This week, he said:

“we question why our family is still being kept in the dark while Jo Farrell is basking in the media spotlight as she talks of building bridges and providing confidence to our family.

We don’t know whether Jo Farrell has been confused or perhaps even caught in a lie, but she has certainly failed to reassure us that she has a grip on this worsening situation.”

Alistair Wilson’s family describe the conduct of the chief constable as “insulting” and “callous”. Does the First Minister agree with the family of Alistair Wilson?

Obviously, this is an incredibly sensitive case. First, I express my sympathy to the Wilson family for the tragedy that they suffered almost 20 years ago. I share their frustration that the case has not been resolved.

Douglas Ross will know that there has been extensive intervention and investigation to try to identify who was responsible for the murder of Alistair Wilson. I very much welcome the fact that the Lord Advocate—who, as Mr Ross will understand, is the independent head of the prosecution service—has instructed that a fresh investigation be undertaken of the case.

On Douglas Ross’s point about the actions of the chief constable, he will, again, appreciate that the police operate with absolute operational independence from the Government. It would be inappropriate of me to indicate any opinion on the stance that has been taken by the chief constable. The matter is for the chief constable to address. Certainly, the First Minister should not indicate to the chief constable what actions she should take in relation to a live investigation.

I know the situation very well. My question is not about the live police investigation but about the comments this week of a family who are still grieving their loss in horrific circumstances. The response from Police Scotland, following the decision by the Lord Advocate, clearly falls below any standard that we should expect—particularly from the chief constable of Police Scotland.

I hope that the First Minister will at least reflect on that language—“insulting” and “callous”. The chief constable is being described by a grieving family as “callous”. I hope that the First Minister will reflect on that and seek to address what could happen.

Alistair Wilson’s case has been unsolved for two decades. That period has spanned the tenures of several chief constables and several Government ministers. The Wilson family have raised concerns about the current chief constable’s handling of the case. However, the Scottish Government is not powerless in the situation; indeed, the First Minister has previously spoken about on-going police investigations in his own constituency. Has he or his justice secretary spoken to the family of Alistair Wilson about their significant concerns? If so, what is being done to address those?

I do not want, in any way, to create any sense that I am not sympathetic and empathetic to the situation in which the Wilson family find themselves. Alistair Wilson was murdered on his own doorstep, and his killer or killers have not been brought to justice. That deeply concerns me.

It is important that I place it on the record that Police Scotland has had formidable success in resolving cases of murder—some of them long in the past—because of improvements in investigative procedures and practices. Those have resulted in a number of people being brought to justice who had previously remained free, having committed some of the worst crimes imaginable in our society. Police Scotland focuses on resolving such matters. That is why I said in my first response to Mr Ross that I welcome the Lord Advocate’s instruction for a further investigation of the case.

Neither I nor the justice secretary have spoken to the Wilson family about their concerns. Mr Ross raises the fact that I have expressed points in relation to previous cases in my own constituency. I say to him, respectfully, that I did that when I was on the back benches; I was not First Minister. It is a very different matter when the First Minister starts commenting on live cases. I need to avoid doing that for the sake of protecting the constitutional separation of responsibility for operational matters that lies with Police Scotland.

I say to Mr Ross that I have every sympathy with the Wilson family. I hope that the actions that the Lord Advocate is taking, which have now been pursued by Police Scotland, will provide a resolution to their deep concerns.

In December last year, the Wilson family complained to the Police Investigations and Review Commissioner about the handling of the police investigation. If we consider the issue of police complaints more widely across the country, we should remember that the current system was set up by the Scottish National Party Government when it centralised Scotland’s police forces back in 2013. The Wilson family’s experience clearly shows that the current system is not fit for purpose.

The Police (Ethics, Conduct and Scrutiny) (Scotland) Bill, which is currently before Parliament, aims to address those failings, but there are still areas where the system falls short. Just yesterday, His Majesty’s Inspectorate of Constabulary in Scotland called for an amendment to the bill that would allow officers to face criminal charges if they abused their positions. I agree with that proposal. I confirm that Scottish Conservatives have lodged an amendment that would add such a provision to the bill, which the Criminal Justice Committee will consider next week. Will the First Minister back the inspectorate’s calls and support the Scottish Conservatives’ amendment, to ensure that any police officers who abuse their positions are held to account?

I have a great deal of sympathy with the point that Mr Ross has raised with me. Ministers will look carefully at the amendment that comes forward at stage 2. The purposes of the Police (Ethics, Conduct and Scrutiny) (Scotland) Bill, which I began scrutinising when I was on the back benches and sat on the Criminal Justice Committee, are coming to stage 2 proceedings in committee; Parliament supported the bill at stage 1.

The issues that His Majesty’s Inspectorate of Constabulary raised in its proposal have not been the subject of consultation as part of the preparation of the bill, so we have to be mindful of that when considering any amendments that are lodged. Parliament prefers to ensure that issues are the subject of consultation.

Having said that, I am sympathetic to the point that Douglas Ross raises. I want to ensure that the Police Investigations and Review Commissioner is able to undertake the types of functions that both Mr Ross and I would want them to undertake. That has to be effective, it has to be transparent and it has to be challenging. As the bill takes its passage through Parliament, I give Mr Ross the assurance that ministers will look carefully at and consider carefully any proposals that will work to strengthen the test that I have put to Parliament.

We would welcome that, because our amendment would strengthen the bill and fill a void that even HMIC has recognised.

The truth is that, although Police Scotland may have let down the Wilson family, the Government has been letting down police officers and the communities that they serve across Scotland. Officer numbers are now at their lowest level for 17 years. The SNP used to promise that it would put 1,000 additional officers on Scotland’s streets, but numbers are down by 1,200 compared with when the SNP created Police Scotland a decade ago.

The number of major investigation team detective inspectors—who investigate the most serious crimes, including murders such as that of Alistair Wilson—is down by a third. Police Scotland is so stretched that it is no longer able to investigate every crime.

Quite frankly, the SNP has left our police to fight crime with one hand tied behind their back, and the results are clear. Violent crime is at its highest level in a decade, and our prisons are so overwhelmed that SNP ministers have been forced to release prisoners en masse. Does the First Minister agree with his deputy, Kate Forbes, who said that, under the SNP, policing has been “stretched to breaking point”?

I have to put on the record the fact that levels of crime in Scotland are currently at 40-year lows. That is a tribute to the work of police officers who are focusing on tackling crime in localities.

I accept that police numbers have fallen. The last census was at the end of June, when police numbers were sitting at 16,207. That is lower than the Government expected, given that we had provided the police with record funding of £1.55 billion, and I expect those numbers to increase in the next census. It should be of some reassurance to Mr Ross that police numbers are strengthening as a consequence of the significant levels of recruitment that the chief constable and Police Scotland are undertaking at the moment.

There is an inherent contradiction in Mr Ross’s question. His accusation is that crime is not being pursued but that the prisons are full. If the prisons are full, that suggests to me that crime is being pursued and that more individuals are being convicted and imprisoned. [ Interruption .]

Let us hear the First Minister.

I respectfully say to Mr Ross that there are challenges in relation to the work of Police Scotland. Police Scotland will take the necessary steps to investigate crimes where there is evidence to do so, and people will be prosecuted where there is a case to do so. That is what we would expect, and that is what we would expect in a system in which we have a 40-year low of crime as a consequence of the Government’s stewardship of police resources in Scotland.