A Homicide Hot Spots Patrol Test in Trinidad and Tobago
Commissioner of Police (Ag) Stephen Williams Trinidad & Tobago
6th International Conference on Evidence-Based Policing
Tuesday 9th July 2013
Background
• A sharp increase in the number of homicide cases in T&T during the last decade
• Over 60% attributed to gang-related activity
• Yet even within high-crime areas, violence in T&T tends to be concentrated in smaller, micro-level crime places – a strong justification for hotspot policing
• Cambridge University <> TTPS partnership
Spatial and Temporal Concentrations of Homicides in T&T
n=1,6621 Jan 2009 – 21 Jan 2013
January
February
March
AprilMay
JuneJuly
August
September
October
November
December
0
20
40
60
80
100
120
140
160
180
200
156
115
129
Homicide – Month
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 0 1 2 3 4 50%
1%
2%
3%
4%
5%
6%
7%
8%
9%
10%
Time of Day (n=1,354) – All Divisions
hour of day
perc
ent
48% in 7 hours
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 0 1 2 3 4 50%
2%
4%
6%
8%
10%
12%
14%
Top 4 Divisions (81% of all Homicides)Port of Spain Northern North Eastern Western
hour of day
Monday Tuesday Wednesday Thursday Friday Saturday Sunday0%
2%
4%
6%
8%
10%
12%
14%
16%
18%
15.5%
12.9%11.9%
14.0% 14.3%
16.4%15.0%
Homicide - Day of Week
Spatial Concentrations – Port of Spain as a case study
Aerial view of the hotspot with the highest homicide rate (n=138 in 4 years)
MOSTLY HANDGUNS!!Robbery Shoot/wound Grand Total
Hand gun 87.52% 84.95% 87.14%
Other firearm 3.32% 3.13% 3.30%
Other weapon 2.64% 4.12% 2.86%
Sawed off shot gun 0.80% 0.49% 0.76%
Shot gun 5.72% 7.30% 5.95%
N 12,818 2,233 15,051
The Trinidad and Tobago Homicide Hotspots Experiment
Targets and Aims
• Reduce Serious Crime by 50% compared to control conditions
• Use all 3 “Triple Ts” of Evidence Based Policing
– Targeting the power few – Testing the Intervention through rigorous science and – Tracking with GPS tracking and effective management
(station-level Compstat)
Selection of Targets• All Police Station Districts that have eligible hotspots within their
geographic boundaries
• Top percentile that is responsible for most of crime and disorder in Trinidad and Tobago
• Excluding Laventille
• Focus heavily on violent crimes (shootings, woundings and homicides) and overall crime harm index
• Focus indirectly on all other serious street crimes
• Increase legitimacy of T&T Police through effective but fair procedures
Proposed Program
• Station-Level Compstat Every 14 days --hearts and minds, targeting predicted crime
• Hot Spot Patrols Hot Times—primarily in vehicles
• Patrol Tracking Maps for Compstat Discussion
• Searches for Guns
• Roadblocks Stop & Search
Process of Random Assignment1. Rank-Order all T&T Stations according to resources available
(n of vehicles, manpower, etc.) and n of serious incidents in 12 months (shootings, homicides, woundings)
2. Exclude Besson Street Police Station--all treatment *
3. Exclude stations with fewer than 5 incidents in 12 months
4. Random assignment of stations across districts
creating 24 pairs______* Extreme outlier with 188 incidents; next in rank is Morvant Police Station with 49 incidents
A B C D E F G H I J0
5
10
15
20
25
30
35
4038
25
16
12 1311
7 6 7 6
Random Assignment - mid range stations
Stations
shoo
tings
+wou
ndin
gs+h
omic
ides
+att
empt
ed h
omic
ides
Grade A Grade BGrade B
Grade C
Grade A
Tracking Patrols
GPS Tracking
1. AVL GPS-based trackers
2. Hand held GPS trackers
3. Crucial: It will help us measure the link between police presence and crime
4. As crucial: Officers’ safety!
Test driving the system:
Bi-Weekly Station-Level Compstat• Common practice in T&T at Division level, but not yet at
station level
• Ongoing feed of data from CAPA
• Winning the hearts and minds of officers with:1. Positive and negative reinforcements 2. Quick response to issues: Discussing challenges and obstacles
at the tactical level3. Accountability: ownership of problems at hotspots by
designated officers
Outcomes
1. N of all crimes2. N of homicides3. Tankebe’s legitimacy surveys4. Crime harm index
2008-Q1
2008-Q2
2008-Q3
2008-Q4
2009-Q1
2009-Q2
2009-Q3
2009-Q4
2010-Q1
2010-Q2
2010-Q3
2010-Q4
2011-Q1
2011-Q2
2011-Q3
2011-Q4
2012-Q1
2012-Q2
2012-Q3
2012-Q4
2013-Q1
0
5000000
10000000
15000000
20000000
25000000
Crime Harm Index - Quarterly Totals
Cameras?
• ….
A Homicide Hot Spots Patrol Test in Trinidad and Tobago
Commissioner of Police (Ag) Stephen Williams Trinidad & Tobago
6th International Conference on Evidence-Based Policing