As the controversy about stop and searches rumbles on, it seems fair to suggest there is a lack of clarity around current police practice.

Comments in the media reveal it's not always clear what a "non-statutory" stop and search is. Sometimes described as "consensual" or "suspicionless", the rationale for the use of this tactic seems ambiguous.

It is difficult to reconcile such practice with the idea of intelligence-led policing, while detection rates for non-statutory searches are much lower than their statutory counterparts. True, non-statutory searches do detect alcohol; but then again, more than half of non-statutory searches in 2014 were for reasons other than alcohol.

This understandable confusion around stop and search is exacerbated by a lack of detail in recording practices. For example, it is not clear how many recorded stop searches for alcohol were in fact simple confiscations. Without clear guidelines for recording, it is difficult to make sense of stop search statistics on young children; whether or not, for example, a child is being used by an adult to conceal unlawful items.

Also, stop and search outcomes remain unclear. We don't know the proportion of stop searches which result in arrest or in prosecution, which makes it difficult to judge the effectiveness or otherwise of the tactic.

There are two related points here. First, recording procedures need to be greatly improved in order to make better sense of police practice and to avoid misunderstanding. Second, stop and search (along with other police powers) needs to be made transparent and accountable.

Without robust, detailed data we don't know what police practice looks like, or how to assess it. Police Scotland Chief Constable Stephen House has called for a non-partisan debate on stop and search; but this isn't possible without reliable figures to inform the discussion.

The arguments on abolishing non-statutory stop and search are well-rehearsed, and now appear to have the support of the Scottish Government, although the position of the Chief Constable now seems less clear. In brief, the case for abolition runs that stop and search is inherently intrusive and therefore needs to be carried out within the law. This doesn't mean shifting towards a more confrontational mode of searching people, as feared by some frontline officers.

Statutory stop searches have been used routinely in some parts of Scotland for many years without public disquiet. It's about legality, due process and the proportionate use of a tactic which is at once, valuable and intrusive.

But there's another story here - one that needs to be aired - which is about the way in which policing fits into the larger landscape of youth justice.

A performance-driven approach to stop and search has meant that far too many stop searches are directed towards young people in some parts of the country, particularly teenage boys.

Even taking into account the recording inconsistencies now acknowledged by Police Scotland, it seems evident that policing encounters, one way or another, impact disproportionately on young people in deprived communities.

Put another way, if Police Scotland had carried out - say, only half the number of recorded stop searches on 16-year-old boys in Glasgow in 2014 - the search rate would be over 1,250 stop searches per 1,000 boys. That's still more stop searches than 16 year old boys.

It's a stark assessment which sit awkwardly with Scotland's progressive approach to youth justice which aims to divert young people away from the formal criminal justice system. With this point in mind, we should proceed carefully around prospective stop and search powers for alcohol.

It has been suggested the abolition of non-statutory stop and search will leave a gap in the legislation. However it appears we don't have the robust evidence to ascertain the size of this gap. We should also be careful not to unnecessarily widen the net.

Stop and search was not the predominant model for policing young people in many communities across Scotland prior to the single service, nor is it the predominant model in many other countries.

At this critical juncture, we now need to look towards a policing approach which does not rely on the widespread use of intrusive measures, whether consent is given or not.

Rather we need to look towards policing which promotes constructive relationships with young people, and complements Scotland's distinctive and positive model of youth justice.

Kath Murray is a criminal justice researcher at the University of Edinburgh.