Less Crime

More Twitter maps

I’ve made available three more live-ish Twitter maps, to add to the Met Police map that I published last year.

The NPAS Twitter Map is for the National Police Air Service. This shows the most recent tweet by each police helicopter in England and Wales (the Police Scotland helicopter doesn’t have a Twitter feed). Police air-support Twitter feeds are really useful for finding out why a helicopter is keeping you awake, and they’re also a good source of aerial pictures (particularly @NPASLondon and @NPAS_Redhill).

The British Transport Police Twitter Map shows the latest tweets by all of the local police teams for that force, and some of their senior officers. I chose them as the second force to create a map for because most of their accounts specify the station that the account is based at, so its easy to post them on a map.

The London Police Twitter Map shows all the police Twitter accounts in London, including those run by the Metropolitan Police, City of London Police, British Transport Police, National Crime Agency and NPAS. There are loads of them so it might take a minute to load all the tweets.

All the maps update every five minutes and tweets from the past hour are marked with a larger icon.

UK open source crime data: accuracy and possibilities for research

I’m one of several authors led by Lisa Tompson (@Lisa_Tompson) on a new paper in Cartography and Geographic Information Science called “UK open source crime data: accuracy and possibilities for research”. The paper looks at the extent to which open crime data published on police.uk can be used for criminological research. The research was conducted using funding from the National Institute for Health Research and the paper is available free online as an open-access publication.

The abstract of the article is:

In the United Kingdom, since 2011 data regarding individual police recorded crimes have been made openly available to the public via the police.uk website. To protect the location privacy of victims these data are obfuscated using geomasking techniques to reduce their spatial accuracy. This paper examines the spatial accuracy of the police.uk data to determine at what level(s) of spatial resolution - if any - it is suitable for analysis in the context of theory testing and falsification, evaluation research, or crime analysis. Police.uk data are compared to police recorded data for one large metropolitan Police Force and spatial accuracy is quantified for four different levels of geography across five crime types. Hypotheses regarding systematic errors are tested using appropriate statistical approaches, including methods of maximum likelihood. Finally, a “best-fit” statistical model is presented to explain the error as well as to develop a model that can correct it. The implications of the findings for researchers using the police.uk data for spatial analysis are discussed.

The when and where of an emerging crime type: The example of metal theft from the railway network of Great Britain

I have a new open-access paper with my PhD supervisors out in the Security Journal titled “The when and where of an emerging crime type: The example of metal theft from the railway network of Great Britain”. The article tests a number of findings from previous work on spatial and temporal patterns of crime to see if those findings hold for the new problem of metal theft from the railway network. Many common patterns in time and space were found to apply to metal theft, but some were not.

The abstract of the article is:

Metal theft has become an increasingly common crime in recent years, but lack of data has limited research into it. The present study used police-recorded crime data to study the spatial and temporal concentration of metal theft from the railway network of Great Britain. Metal theft was found to exhibit only weak seasonality, to be concentrated at night and to cluster in a few locations close to - but not in - major cities. Repeat-victimisation risk continued for longer than has been found for other crime types. These and other features appear to point to metal theft being a planned, rather than opportunistic, offence and to the role of scrap-metal dealers as facilitators.

Thanks to the UCL Library open-access team, this article is free to view online.

Met Police Twitter map

As part of my interest in how UK police use Twitter, I’ve added a live-ish map showing all the Metropolitan Police Service (MPS) Twitter accounts and the most recent tweet from each account. The map updates every five minutes and automatically highlights the most-recent tweet and all accounts that have sent a tweet in the past hour.

Although the map is live-ish, to keep down calls to the Twitter API tweets are cached on a local server and then put on the map. This means that, depending on when you load the map you might not get the very latest tweets immediately.

At present I’ve only done this for the MPS because I have to geocode all the accounts manually and that takes time. I’ve geocoded borough and neighbourhood accounts to the geographic centre of the area that they serve, which may occasionally suggest an officer is based in the middle of a park (although I seem to have avoided any locations being in lakes). The main MPS account (@metpoliceuk) is geocoded to New Scotland Yard, @MPSinthesky to their base at Lippitts Hill, @MPSonthewater to their base at Wapping, @MPSSTC to their headquarters at Palestra in Blackfriars and @MetPoliceEvents to the Special Operations Room (or, in Daily-Mail speak, “secret bunker”) on Lambeth Road.

I couldn’t geocode some accounts such as @MPSOntheStreet, @MPSFootballUnit, @MPSSpecials, @CdrRodhouseMPS, @CdrLetchfordMPS and @BJH251 because they either don’t have a single base or I don’t know where they’re based. If you have locations for any of these accounts, please let me know on Twitter.

I haven’t tested the map on anything older than Internet Explorer 8, so if you’re using an old browser then browse happy (or ask your IT department to upgrade their software).