There are a number of fundamental principles by which the police complaints procedure in Scotland should abide:

it should be independent, it should investigate complaints as promptly as it can, and it should have the confidence of the public. Policing in the UK is, after all, by consent of the people.

However, in all of these areas, the relatively new complaints system does not appear to be working as well as it should, with new figures on allegations of racism adding to the doubts. The figures, obtained by a Freedom of Information request, show that, of the hundreds of allegations made against the police since 2009, only a handful have been upheld. In total over the last five years, the number of cases upheld was three per cent, although the figure for the new single force, Police Scotland, is lower at one per cent.

The figures can partly be explained by a number of cases being vexatious, but a rate of upheld cases as low as three per cent should still sound the sirens of alarm. The 4 per cent conviction rate for rape in Scotland is a national scandal and yet, in an important are such as racism, the figure is even lower.

The fact that only one complaint has been upheld during the first months of Police Scotland seems particularly worrying and adds to concerns raised from the start that a reform of the complaints procedure would be required as regards the single force. Before the creation of the force, when a complaint was lodged against one force, it was investigated by another, but clearly this is not possible when there is one single force.When a non-criminal complaint is lodged, it is handled by the Professional Standards Department of Police Scotland and then, if that proves unsatisfactory, the new Police Investigations and Review Commissioner, or Pirc, takes over. But concerns about independence have persisted. Police experience will always be required on such a body but it does not help to dispel concerns about impartiality that it is staffed mostly by people with a police background.

The risk is that, on a subject such as racism, Pirc will not be sufficiently questioning of police evidence. The Police Complaints Commission in England is a different body but, in the case of Mark Duggan, it was criticised for too readily accepting the police account of events and the same danger could exist at Pirc. Officers who do not see themselves as racist may struggle to see racism in others.

On the question of complaints being investigated as promptly as possible, the figures show there are still some unresolved cases going back as far as 2010, something else that could undermine Pirc's ability to abide by the third principle: that it should have the confidence of the public.

Confidence will be won only if public believes complaints are investigated fairly, thoroughly and impartially. In the light of the figures on racism claims, the best way forward might be for Pirc to look again at the balance of its staff. As an organisation, the case against it has not been proven but, equally, it still has some way to go before it can say that it has the confidence of the public it serves.