Crime data is never perfect. By its very nature, crime is usually secret and consequently under-reported. All crime data has three components; about the crime, the perpetrator and the victim. We carry only data about reported crime. Every crime or ASB incident is semi-anonymised to protect the victim and ongoing legal proceedings and then matched to a close geographical location and put into broad crime categories and finally date-stamped by month and year. From this we build the database that you are looking at now. If you spot something, please let us know – we can't pay you but we will gladly credit you with your observation, should you want that.
Here is a running list of broad points to be aware of, in no particular order:
1. Population data is based on last census in 2011 and revised annual estimates from 2013 onwards
The UK does not have a very precise idea of how many people are in the country at any one time. People come and go, are born and pass away but by and large the population is growing and more mobile than the last census of 2011. Where possible, we have added revised estimates for mid-2013 onwards. We will update with more annual estimates as and when they become available. We are confident that there are no newer population datasets available for all our data.
It's by no means a perfect measure. One of the early findings of this website is that a lot of crime tends to happen where people are not resident. What really counts is the total throughput of population in a given area as to put it crudely, this creates more opportunities for crime. So the answer is to always adjust for daytime population as well as residential populations to give a clearer picture. This is a unique capability of UKCrimeStats - daytime population adjusted crime rates.
3. Police Ranks
We had to work hard cleaning up the Police Rank data. A bit like the different branches of the Armed Forces, for reasons of evolution and history, the 43 Police Forces do not have an identical rank system.
Different Police Forces can refer to the same rank differently. For example, Special Constable ('SC') is known as 'MSC' in the London Metropolitan. These have been accounted for where known. There is still confusion around the data where the Police Forces have used the acronym of the rank/role e.g. 'PS'. We don't know if this refers to Police Sergeant, or, judging by the large number of these, more likely 'Police Staff' which we've seen used, which probably equates to a Police Constable.
How does this affect www.ukcrimestats.com?
We have narrowed down the ranks to the following; Chief Inspector, Inspector, Sergeant, Police Constable, and PCSO. This is what you will see on our Officers page when you click on the By Rank section. However, we have kept some of the others (e.g. where role is described rather than rank) and kept all of them on as registered officers.
4. When crimes merge
There are only 12 types of crime stratified by the data; anti-social behaviour, burglary, other crime (consisting of shoplifting, drugs, criminal damage and arson, public disorder and weapons, other theft), robbery, vehicle crime, and violent crime. But what happens when there is a violent burglary, is this one crime or two? We now have it on good authority that there is an order of hierarchy according to the length of sentence per crime committed. So in this example, if the burglary involved homicide, then this would be registered as a violent crime, not a burglary. But if there was a relatively small and ineffectual violent blow landed by the perpetrator on the victim but a great deal of valuable items were burgled, then it is registered as a burglary. So a combination of different offences are recorded as one crime according to the hierarchy of potential sentencing length.