“Prediction is very difficult, especially if it’s about the future.” Nils Bohr, Nobel laureate in Physics
Predictive Mapping First advanced in 2004 (Johnson et al) Increased risk within 400m for 6/7 weeks Local view in 2005/6 = not useful – 400m from any Burglary in Leigh covers all of Leigh Utilised in Trafford & linked to 25% reduction in Burglary Dwelling Let’s have another look… But… “the implementation of a strategy for which every burgled household and neighbours within 400m received crime reduction attention would require substantial resources…” (Johnson et al, 2006, Home Office)
The Changing Face of Near Repeats… Initial research based on 2003/4 data Wigan BD in 2003/4 = 2,813 Wigan BD in 2010/1 = 1,266 55% reduction Repeats and Near Repeats also likely to have reduced
Not Everything Repeats… 43% of Wigan’s Burglaries do not have a near repeat within 12 weeks Much more likely in Atherton and Leigh Ecological fallacy… Neighbourhood Area Burglary Offences 2010 Burglary Offences with no Near Repeat within 12 weeks % of Offences with no Near Repeats Pemberton (L1) % Wigan (L2) % Hindley (L3) % Leigh (L4) % Atherton (L5) %
GI* Technique GI* provides focus allied to statistical significance Some overlap with strategic clusters Highlights some new areas too But… Are any of these techniques predictive?
Predictive Abilities High volumes vs manageable intervention points
More supporting analysis… Near Repeats identified and hotspotted Still a large area to cover Can we focus in any further?
‘Gaps In The Clouds’ Near repeat hotspot Overlaid with all 2010 Burglaries that DIDN’T see a near repeat Reveals 4 areas where a Burglary ALWAYS sees a near repeat Clear focus…
Near Repeat hotspots + Analyse2Advance Clusters + GI* grids All 4 Near Repeat hotspots contain Analyse2Advance Clusters Significant grids on top of Analyse2Advance Clusters on top of Near Repeat hotspots = top priority Refresh GI* weekly to keep live – tactical analysis underpinned by Strategic analysis Stacking up the Evidence
Local picture in Leigh Stacking up the Evidence
A Combined Approach Hierarchy of risk based on crimes falling into GI* grids Strategic clusters Near repeat hotspots Identify offenders living/operating within area and target (linked to IOM work) Offences outside these areas should be prioritised after this but based on local knowledge of Near Repeats: –Pemberton - <300m <7days emphasis on day 1 –Wigan - <300m <7 days –Hindley – no near repeat evidence –Leigh – <300m <1 day –Atherton - <200m <7 days emphasis on day 3
Current Picture Initial pilot exercise running since 24/10/ % strike rate – importantly, in a manageable area Number of arrests in identified areas Monitoring patrol locations via dip sampling Offender element to be added in soon Partnership approach to be developed Works with other thematic areas – TFMV, FDR3s
Predictive Mapping GMAC - Wigan 2011 Ian Bullen – Strategic Analytical Partnership Co-ordinator9 th November 2011 Wigan Strategic Assessment