ONE of the early concerns raised when the new single Scottish police force was first mooted was what would happen when there was a need to investigate the police themselves.

The existing system, whereby serious complaints about a Scottish force were looked into by a team from one of the country's other forces could no longer operate unless, some suggested, police investigators were recruited from south of the Border.

The investigating of one force by another was never without its problems, of course. The history of police misconduct investigations across the UK is a sorry one, replete with examples of clear wrongdoing where no officer is ever disciplined, or senior officers who are accused of misconduct are allowed to retire before an investigation has run its course.

A different solution was found and a new body, the Police Investigations and Review Commission (PIRC) has been set up to handle such issues.

An independent watchdog should be able to rid itself of the suggestion that investigations are compromised when police investigate themselves. But will it?

The news that eight of the most senior 11 posts are to go to former police officers, and that people with a police background will make up 13 out of 20 staff overall, raises inevitable questions.

Can an organisation so dominated by police "insiders" investigate complaints and alleged misconduct, and convince those who raise concerns that they have been addressed with an independent eye?

The English example of the Independent Police Complaints Commission (IPCC) is instructive. The IPCC has been criticised over its response to a number of cases in England, including the deaths of both newspaper vendor Ian Tomlinson and that of Mark Duggan, which helped provoke the 2011 summer riots. The body has been heavily criticised for too readily accepting the police account of the events leading up to the "plebgate" row involving former Government Chief Whip Andrew Mitchell.

Among a number of recommendations for change, a parliamentary committee recently called for the body to better funded. But it also demanded the number of police officers on the commission be cut to no more than 20%. It is currently 33% – so former police officers already make up a much lower proportion of its staff than they will at its Scottish counterpart.

Westminster's Home Affairs Committee concluded the body had too often contributed to public mistrust, rather than reduced it, saying: "Without faith in the commission, the damaged public opinion of the police cannot be restored." The same surely applies in Scotland.

The new body argues that the former officers chosen are the best people for the job and have specialised skills. It needs people who are skilled in issues such as liaising with families, intelligence techniques and crime scene management, a spokeswoman said, and the successful candidates were those judged most able.

It is unquestionably true that some police expertise and skills of inquiry are necessary for such a body. A panel with no former police officers would also lack credibility. But the balance could surely be improved – there are plenty of other people in Scotland with backgrounds in investigative and regulatory roles.

Leading human rights lawyer John Scott QC is right to say this is an area where perceptions are important. He is particularly concerned about the prevalence of former officers taking senior PIRC posts, pointing out that organisational ethos generally comes from the top.

He also points out that bias can be subconscious, comparing the way a police officer may sympathise with a force to the warm feelings a departed pupil may have towards their old school, or a former resident to their home town.

The PIRC suggests that over time as its staff become more skilled, the dependence on former officers may reduce.

It must prioritise ensuring that this happens, so the public can be convinced that – in matters of police wrongdoing – justice will be done, and be seen to be done.