4. Changes to counting rules for handling offensive weapons
Scotland’s recorded crime statistics are produced by Scottish Government statisticians, working to the Code of Practice for Official Statistics  . This process is supported by the Scottish Crime Recording Board ( SCRB), which exists to support the production of accurate and objective statistics on crime in Scotland. It does this primarily through its role as the guardian of, and ultimate decision maker on, issues related to the Scottish Crime Recording Standard  ( SCRS).
Position before the change
Prior to the 1 st April 2017, any crime or offence committed with a weapon against a person in a public setting was counted once with the weapon-possession treated as an aggravation of that crime or offence. For example, if a person reported to the police that they had been threatened in a public setting by an individual with a knife, the possession of the knife would have been considered an aggravation of the threatening behaviour. Given this, statistics on recorded crimes of handling offensive weapons up to and including 2016-17 only relate to where the weapon has not been used to commit a crime against a person in a public setting. An example of such a case could be where police officers search an individual under the Misuse of Drugs Act, and during this time uncover a weapon, or officers may receive witness reports of someone being in possession of a weapon whilst they are in a public setting.
Position after the change
The SCRB has changed the approach outlined above so that from the 1 st April 2017, any crime or offence committed with a weapon against a person in a public setting will be recorded with the weapon possession treated as a separate crime (i.e. the aggravation rule outlined above has been removed). Under this new position, if a person reported to the police that they had been threatened in a public setting by an individual with a knife – two crimes or offences would now be recorded – one for the threatening behaviour and a second for handling a bladed or pointed article in a public setting.
This change will lead to additional crimes of weapon possession being recorded by the police from 2017-18 onwards.
The SCRB made the change outlined above to better reflect criminal law in this area, so that a perpetrator committing a crime or offence with a weapon against a person in a public setting will now generally be proceeded against for both the crime or offence committed with the weapon and possession of the weapon. It should be noted this change only affects incidents that occur in a public setting (i.e. fulfills the condition of the Criminal Law (Consolidation) (Scotland) Act referred to in Section 1).
Statisticians provided users with further details on this change through a SCOTSTAT announcement on the 5 th May 2017. The National Statistics on Recorded Crime for the 2017-18 reporting year, due to be published in September 2018, will be the first bulletin to reflect this change.
Quality of recording practice for crimes of Handling Offensive Weapons
As outlined above, the new approach to recording crimes of handling offensive weapons was introduced from the 1 st April 2017. Given the impact this change is likely to have on the Recorded Crime National Statistics, Scottish Government statisticians undertook a subsequent review of crime records to test whether it had been implemented effectively. This exercise, carried out in collaborative with Police Scotland, had two outcomes. The first is a report into the quality of crime recording decisions for handling offensive weapons (presented below) and the second a summary of these crimes’ characteristics (providing additional information on this type of offending). This is presented in Section 3.
A random sample of 1,000 crimes of handling an offensive weapon was selected from April to September 2017 (i.e. the first 6 months following the change to recording practice). This represented around a quarter of all crimes of handling offensive weapons recorded during this time. The sample was split into 500 crimes of handling an offensive weapon which wasn’t used to commit a further crime or offence against a person (i.e. the existing measure and shortened to ‘weapon not used’) and 500 crimes of using an offensive weapon to commit a further crime or offence against a person (i.e. the additional cases recorded since the 1 st April 2017 and shortened to ‘weapon used’). For each crime selected, the record was reviewed to determine if the description of the incident was consistent with the crime-classification assigned to it.
Findings from the 2017 Sample
The findings of this review are shown in Table 16, which presents the percentage of crimes correctly classified for each of Police Scotland’s 13 divisions and Scotland as a whole. The results are generally discussed at the national level, unless otherwise stated, as most differences at the divisional level were not statistically significant.
Overall, 91% of the 1,000 crimes sampled were correctly classified (i.e. the description of the event provided in the crime record correctly corresponded to the crime-classification assigned to it). Two divisions were significantly higher than the Scottish average (Forth Valley and Tayside).
For those newly recorded crimes of using an offensive weapon to commit a further crime or offence against a person, the percentage of cases correctly classified was 93%. This suggests that the implementation of new codes to separately identify these cases within the statistics has gone well. For crimes of handling but not using an offensive weapon (i.e. the existing measure), the percentage of cases correctly classified was 89%.
The review found that one way of further improving these figures would be to ensure the correct application of the ‘weapon used’/‘weapon not used’ distinction when categorising a crime. Of the 1,000 crimes sampled – 25 involved an offensive weapon being used to commit a crime or offence against a person, but the case had been classified as a crime of ‘weapon not used’. There were a further 14 cases where the crime had been classified as ‘weapon used’ but the weapon had not been used to commit a crime or offence against a person. These discrepancies would make no difference when looking at the overall recorded crime for handling offensive weapons, however during the period being sampled this suggests the resulting statistics would slightly over-estimate the number of ‘weapons not used’ crimes and under-estimate the ‘weapons used’ measure. If the ‘weapon used’/‘weapon not used’ distinction was correctly applied in all cases, the percentage of crimes correctly classified overall would increase to 96% for the ‘weapon used’ measure and 94% for the ‘weapon not used’ measure.
The review also found several examples of a crime being recorded for handling an offensive weapon, but there was insufficient evidence to confirm this had occurred. This could be because the weapon had been seen or used in a private dwelling (the associated Act only applies to a public setting) or the level of corroboration required in the SCRS to record a crime of handling a weapon hadn’t been met (for example officers may only have had CCTV images suggesting someone was in possession of a weapon or lacked a second witness to a crime of weapon possession in cases where the weapon wasn’t used). Of the 1,000 crimes sampled, 27 involved this type of error. The effect of this is to somewhat over-estimate the number of weapons crimes, albeit the review did identify 12 examples where the crime selected was correctly classified, but the case notes revealed the presence of a second or third weapon that hadn’t been recorded as a separate crime(s).
We therefore conclude that the collective impact of these errors on the total volume of recorded crime for weapon possession in 2017 is likely to be limited. However, it should be noted that this review only looked at cases where a crime of handling an offensive weapon had been recorded. What cannot be measured by this approach is how frequently an incident involving the possession of a weapon is recorded by the police without an associated crime being added. Whilst there is no evidence to suggest this is likely to be a significant issue, a separate study by statisticians into the characteristics of non-sexual violence in Scotland (based on a random sample of crime records  ) will identify whether there are any examples of non-sexual violent crime where a crime of weapon possession should have been recorded but wasn’t.
Reviewing Weapons Crime from an earlier Period
Statisticians also reviewed a random sample of 500 crimes for the ‘weapons not used’ category, covering the six months from April to September 2013. This part of the review was undertaken to measure how effectively the ‘weapon not used’ category was functioning before the change to recording practice came into effect on the 1 st April 2017. Whilst a later period could have been chosen for this test, the selected timescale of April to September 2013 had two distinct advantages. The first was that it allowed an assessment to be made of the likely position inherited by Police Scotland from the legacy forces (with the national force formally established on the 1 st April 2013). The second is that by having four years between samples of the ‘weapon not used’ category (2013 and 2017), the research element of this exercise stood a better chance of detecting any significant changes in the characteristics of these crimes (as opposed to selecting a period immediately prior to the change in recording practice).
The findings of this additional sample are shown in Table 17, which presents the percentage of crimes correctly classified for each of the 13 Police Scotland divisions and Scotland as a whole. Overall, 84% of the 500 crimes sampled were correctly classified. One division (Highlands & Islands) was significantly lower than the national average, whilst three were significantly higher (Ayrshire, Dumfries & Galloway and Lanarkshire). The percentage of cases correctly classified during the first six months of Police Scotland’s existence (along with a degree of variation at the divisional level), suggests that the national force inherited a somewhat mixed position, where there was room for further improvement in the quality of recording practice.
The most common error for a ‘weapon not used’ crime in 2013 was where the previously discussed aggravation rule, whereby a crime of weapon possession shouldn’t be recorded when the weapon has been used in a crime or offence against a person, hadn’t been correctly applied. Of the 500 crimes sampled, 53 involved cases where the weapon had been used in a public setting to commit a crime or offence against a person. In all these cases, the possession of a weapon should have been treated as an aggravation of that crime or offence, rather than been recorded as a separate crime of weapon possession. On their own, these errors will lead to an over-estimate in the volume of recorded crime for weapon possession, relative to the SCRS guidance that applied at the time.
This issue affected some divisions more than others, with six areas having at least 15% of their ‘weapon not used’ sample contain an error in the application of the aggravation rule (i.e. the weapon had been used). Those areas were Argyll & West Dunbartonshire, Forth Valley, Fife, Edinburgh, Highlands & Islands and Lothian & Borders. The prevalence of this error type was much lower in the other seven divisions, suggesting that a degree of caution is needed if comparing statistics on weapons possession between divisions during this time.
The other types of discrepancy found in the sample were similar to those described above for the 2017 exercise – mostly cases where an incorrect code had been used to classify the crime (for example where a knife or other sharp object had been classified as an ‘offensive weapon’ rather than the specific code for a ‘bladed weapon’) or there was insufficient evidence in the record to confirm that a crime of weapon possession should have been recorded.
Comparing findings from 2013 and 2017
As noted above, from the 1 st April 2017 the aggravation rule no longer applied – with police officers now expected to record a separate crime of handling an offensive weapon, where such a weapon is used to commit another crime or offence against a person in a public setting. Given this, the error found in the earlier sample from 2013 (whereby 53 separate crimes of weapon possession were recorded instead of being treated as an aggravation) can no longer occur. It is likely this change has contributed to a significant improvement in the quality of crime recording practice for those six divisions referred to above that had the most errors in the application of the aggravation rule. Collectively, 75% of ‘weapons not used’ crimes were classified correctly for those six divisions in 2013, rising to 88% by 2017. This increase in turn contributed to a higher percentage of correctly classified crimes for the ‘weapon not used’ category in 2017 (at 89% across Scotland, compared to 84% in 2013).
Summary of findings, their impact on the National Statistics and next steps
- The clear majority of crimes recorded for possessing an offensive weapon in 2017 were classified and counted correctly by Police Scotland.
- The review suggests that the additional codes introduced to identify those new cases of using an offensive weapon to commit a crime or offence against a person in a public setting, have been effectively implemented during this initial period.
- The position could be further improved, in particular for the existing measure of possessing (but not using) an offensive weapon in a public setting. Scottish Government Statisticians and Police Scotland will work together in the coming months to support this, through meeting to discuss the findings of this review and what associated actions may help – including possible enhancements to the guidance on recording these crimes or training for officers. This process will be overseen by the Scottish Crime Recording Board.
- The review identifies two areas that users of the National Statistics on police recorded crime should note going forward.
- The first is that statistical comparisons between Police Scotland divisions in the volume of weapons crime recorded prior to 1 st April 2017 should be undertaken with some caution - where such a comparison includes an area that didn’t consistently apply the aggravation rule for counting crimes of weapon possession.
- The second is that the review identified an over-count in crimes of handling offensive weapons (not used) in 2013, which had improved by 2017 (this may have been due, at least in part, to the introduction of the change to recording guidance for crimes of weapon possession). The review also suggests some over-estimate in crimes of handling (but not using) offensive weapons remained in 2017. This suggests that short-term changes in the volume of crime recorded for possessing an offensive weapon (not used) should be regarded with some caution.
- Time series comparisons in the volume of crime recorded for possessing an offensive weapon are likely to be reliable and reflective of real change over the medium to longer term, as the significant reduction in recorded crimes of weapon possession has been replicated in other sources (see Section 2).
- This advice will be incorporated into the upcoming 2017-18 National Statistics on recorded crime, which will be published in September 2018. Going forward (and as noted above) statisticians will also work with Police Scotland and the Scottish Crime Recording Board to promote further improvement in recording practice for crimes of handling offensive weapons.