The 1st of April 2013 is a date that looms large in the diary of John McNeill, the Police Complaints Commissioner of Scotland (PCCS).

On that day he will take control of a new service with an expanded remit and greater powers in holding Scotland’s forthcoming single police force to account.

McNeill’s new job title – as Police Investigations and Review Commissioner (PIRC) – may not sound radically different to the old one.

But the gentle Northern Irishman is under no illusions that the change in focus will be seismic.

To illustrate the sea change, Professor McNeill’s current role confines him to reviewing the way in which the police in Scotland handle non-criminal complaints from the public.

As the PCCS’s latest annual report of complaints about the police shows – an advanced copy of which was seen by Holyrood – most of those cases, while not trivial, look at allegations of ‘irregular procedure’ or ‘incivility’ by police officers.

With the change in focus, McNeill’s role will take him into uncharted territory, with the ability to investigate matters of serious criminality.

He tells Holyrood: “On the 1st April next year, we will have an enlarged role with enhanced powers. We will continue to review the cases that we receive that are of a non-criminal nature but we will then move into other areas. For example, I will investigate allegations of serious criminality that the Crown Office refers to me. I will look at death or serious injury in police custody or death and serious injury following contact with the police.

“I will look at complaints against senior police officers that the chairman, Vic Emery, or the Scottish Police Authority refer to me. I’ll look at referrals from the Chief Constable. And significantly, I have a public interest opportunity where it’s the commissioner’s call, it will be my call, whether or not I want to investigate something in the public interest.” As to what the ‘public interest’ might constitute, McNeill concedes it will be a power used infrequently but gives some examples.

“It’s quite likely if it is used, if I choose to use it, it will be something that’s already exercised and excited the public, politicians and the media and, indeed, the Crown Office itself.

“For example, it might be policing of large-scale demonstrations, it may be something like the tragic events at Hillsborough, it may be some type of endemic concern, institutional malpractice or something. It’s very difficult to visualise it because we’re very fortunate in Scotland that we live in a society where, for example, police only use firearms about once a year, tasers are not used very frequently, very few people die in police custody and very few people die following contact with the police. And I think that’s great.” Among the complaints levelled most often against the police is that they wield too much power and have a poor track record in investigating themselves.

The perception can often be that police bodies investigating fellow police bodies are a closed shop and forces strive to look after their own.

McNeill is aware of those pitfalls and is keen to point out the independence of his role and of outside bodies to hold him to account for his decisions.

He says: “I’m very confident that in Scotland there will be an additional layer of assurance provided by the establishment of PIRC. We’ve got the assurance of the independence of the Lord Advocate and the independence of the Crown Office prosecution service.” He adds: “I’m held to account because if you’re not satisfied, you can seek a judicial review, you can go to the Scottish Public Service Ombudsman, you could go to the Scottish ministers who have appointed me.” At this stage, McNeill concedes the demands for the new service are unlikely to be fully known until PIRC is up and running.

But he is in the process of appointing a top-class director of investigations, with a likely police background and on a salary of £60,000-plus, as well as an experienced team of investigators.

He says: “I’ll have a budget of just over £2.6 million; the projected staff numbers are about 41. There will be 23 or so investigators, seven conducting reviews into non-criminal complaints and we’ll have 11 in the corporate services, which cuts right across the review and investigative bodies.” In terms of workload, McNeill, based on current best-guess estimates, believes the actual number of cases will be quite low, although it is the complex nature of the cases that could determine how much resourcing is required.

He says: “If you look at the projected demand from referrals from the Crown into allegations of serious criminality, I expect that to be in the single figures. Deaths following contact, deaths in custody, discharge of firearms, including tasers, again, I expect that to be in single figures.

“Referrals from the Scottish Police Authority are unknown but unlikely to be very high given that there is the one command team. Again, I would expect, if at all, that would be in single figures.” He adds: “I am constantly reminded that it’s not just about the scale but the complexity of the cases.

The complexity of any one investigation has the potential to suck in a lot of resources, which is why I have agreed with other members of the project board that at the end of the first year of operation we will review the capability and capacity of PIRC.” This year’s annual report has seen a 4.1 per cent rise in the number of complaint cases received by Scotland’s eight police forces.

In 2010/11 there were 4,206 complaints versus 4,379 in 2011/12 on matters ranging from irregular procedure to neglect of duty and excessive force.

At the same time, the number of allegations contained within each case file rose by 13.1 per cent but McNeill does not believe this is indicative of a problem in policing.

He explains: “If you look at the overall trend it is downward [since 2008/09]; complaints against policing bodies are decreasing. There’s been a bit of a blip this year; it’s up about four per cent on previous years. But the really good news is if you look, for example, at Strathclyde, which is about 40 per cent or more of Scotland and has the largest number of police officers, they’ve recorded the lowest rates. They’ve got just about six complaints per 10,000 head of population. That’s pretty remarkable.” McNeill points out in fact that one of the benefits of a single police force, under new Chief Constable Stephen House, is that the complaints process can be harmonised.

He says: “There have been inconsistencies in approach across the eight areas of Scotland. As we go forward, I would expect to see one common culture and one common ethical code, one common operating standard.

“I think it will be to the benefit of the people of Scotland; the exercise of the powers will be much more uniform and effective. I’m confident in Stephen House [that he] is a very professional police officer leading it; I’m confident that he will appoint an equally competent command team.

And I’m confident that Vic Emery and the Scottish Police Authority will hold the command team and the police to account.” McNeill says also that he wants the police to be better at reporting the outcomes of investigations so the key stakeholders, most often families, are kept in the loop.

And he says he would like to see complaints resolved as “effectively and as soon as possible” at the “lowest possible level”.

He explains: “They [police forces] tend to over-investigate and under-report. What tends to happen all too often is the police put a lot of resources into exploring why something went wrong and then they let themselves down in the letter they write to the person explaining all the work they’ve carried out.” But he insists: “The new policing landscape in Scotland will be more effective and will be subject to enhanced independence, accountability and greater transparency. The work we are doing now will ensure that the Scottish Government, the Police Service of Scotland, the Scottish Police Authority, the Crown Office and ourselves will be aligned and that the public can be confident that there will be independent oversight and investigations of the single force.”