Data Driven Policing: Homicide Concentration and Distribution Patterns in London Detective Superintendent Mark Jackson & Barak Ariel, PhD

All Homicide Offences (1st Apr 00 to 31st Mar 10)

Is Homicide a random event in time? Is Homicide a random event in space? What are the possible links between homicide locations, offenders, victims and other factors, at the micro-place level? Research Questions?

The stability of crime trends at places over time suggests a “strong coupling” of crime to place David Weisburd, Cody W. Telep, Anthony A. Braga (2010). The Importance of Place in Policing: Empirical Evidence and Policy Recommendations. Bra Publications Place-Based Criminology

74% of serious gun crime assault was committed in 5% of street and intersections (Braga et al 2010) 5% of addresses/intersections produce 100% of the calls for predatory crimes, i.e. robbery (Sherman et al 1989) 3.5% of addresses account for 50% of crime calls (Sherman et al 1987) (some of the) Research Evidence:

London Metropolitan Police Data: 10 year period from ( ) within the Metropolitan Police area of London Homicide Locations = 1,664 (98.2% geo-coded) Victims Locations = 1,714 (87.3% geo-coded) Offenders Location = 2,382 (84.3% geo-coded) Socioeconomic Deprivation Measures for 4,760 LSOAs

Temporal Patterns

London Homicides ( ) by Year (n=1,714)

London Homicides ( ) by Month (n=1,664)

London Homicides ( ) by Day of Week (n=1,664)

London Homicides ( ) by Hour of Day (n=1,664)

Spatial Patterns

Homicide Offence locations by Borough

Homicide Offence locations by Ward

Homicide Offence locations by LSOA

Or put it another way

Zero Homicides (1st Apr 00 to 31st Mar 10)

Homicide Offence locations in Westminster Wards West End St James

All Domestic Violence Homicides ( to )

All Gun-Related Homicides ( to )

All Knife-Related Homicides ( to )

Connecting Homicide Places to People at LSOA level

LSOA Characteristics Greater Metropolitan City LSOA Homicide Locations LSOA Victim Locations LSOA Offender Locations N 4,7601,2401,2021,386 Population size M1,6341,4962,030 Mean N of persons 1,505-1,6261,6601,6451,585 Area (Hectares) Density rate per Hectare

72% of London's LSOAs (n=3,414) did not have a resident accused of homicide Homicide Offenders 75.5% (n=3,597) of LSOAs did not have a resident victim of homicide Homicide Victims

6% of LSOAs contributed 42% of homicides over 10 year period Concentrations of Homicide

9% of LSOAs contributed 53% of homicide offenders over 10 year period Concentrations of Offenders

5% of LSOAs contributed 35% of homicide victims over 10 year period Concentrations of Victims

Deprivation Levels at LSOA

There are predictable “hot times” of homicide The stability of homicide trends at places over time suggests a “strong coupling” of: 1.Homicides to place (6%  42%) 2.Homicide offenders to place (9%  53%) 3.Homicide victims to place (5%  35%) Summary 1

2% of homicide offenders kill within their LSOA 60% of victims are killed within their LSOA Medium-size relationship between overall crime patterns & deprivation levels with: 1.Homicide LSOA (ES = 0.5) 2.Homicide victims LSOA (ES = 0.5) Small but negative relationship between overall crime patterns & deprivation levels with: Homicide offenders (ES = -0.14) Summary 2

Data Driven Policing: Homicide Concentration and Distribution Patterns in London Detective Superintendent Mark Jackson & Barak Ariel, PhD