1. Recent Advances in Evidence-Based Policing Around the World: 2015
Lawrence W. Sherman
Heather Strang
Cambridge University

2. Research is not enough: pushing research into practice

3. Three Kinds of Advances in 2015
Advancing the evidence base
--Offenders
--Places
--Victims
Advancing Police Agency Uses of Evidence
Durham, W. Australia, Uruguay, Trinidad & Tobago,
Advancing Governmental Use of Evidence

4. Triple-T Against Crime & Harm L.W. Sherman Crime & Justice 42 (2015)
Evidence-Based
Policing
Targeting
Testing
Tracking

5. TED Map: Evidence-Based Policing
Targeting Testing Tracking
Power Few Sample Measure
Prediction Comparison Feed Back
Triage Integrity Correction

6. Tracking Patrol in Murder Spots 2014

7. Big Picture of Policing: West Mids

9. Feed Back
COMPSTAT (New York)
Cop-Stat (Trinidad)

10. Implementation
If Feed Back does not work, Apply corrections --Ride along at night --Change leaders --Incentives --Discipline
SSP David Abraham

11. How Much Patrol Dosage is Enough?
Most hot spots RCTs do not even measure it in Experimental areas.
Let alone in control areas
No check on integrity
Even bigger a problem for police ops than for research
Trinidad & Tobago now monitors dosage like a hospital

12. Trinidad & Tobago
TARGETING Pioneers use of GPS For geo-fencing 230 homicide hot spots for more patrol, stops TESTING Uses RCT to estimate effects on murder, guns TRACKING Pioneers weekly feedback to drive up patrols, drive down murder
Stephen Williams, MSt Commissioner of Police

13. Logic of RCT Before: 71 murder/shootings EXP
71 murder/shooting Control
During 56 murder/shootings EXP
95 murder/shooting Control
EXPECT 95; RESULT 56; = 39 prevented
41% Less than Control

14. Trinidad Randomized Trial

15. T-20 vs. Control

16. 20 Pairs of Stations—Hot Spots or Not

17. SEBP Special Issue Vol. 25, No. 1 March 2015
Evidence-Based Policing: From Academics to Professionals
Sherman & Murray,
guest editors

18. 1. Targeting Evidence for Policing What Works, What Doesn’t
Offenders Places Victims
Philadelphia Guns Suffolk DV
Visits (Dyads)
Turning Point HMOs Hants DV
(CARA)
E-Tag IOM CT & Trust

19. Inside Hot Spots—and Out
Policing Offenders
What’s New?
Inside Hot Spots—and Out

20. 3d Philadelphia Hot Spots RCT Temple University
81 Hot “Spots” (22 football fields) 3 groups, block RCT 20 Experimental, 7 control --POP (20+7) --Patrol (20 + 7) --Offender Focus (20 +7)
Elizabeth Groff Jerry Ratcliffe

21. What is “Offender Contact. ” E. Groff, J
What is “Offender Contact?” E. Groff, J. Ratcliffe et al CRIMINOLOGY 2015
Philadelphia officers made frequent contact with prolific offenders identified by INTELLIGENCE units, from
making small talk with a known offender to
serving arrest warrants for a recently committed offense. The most frequent tactic used was
surveillance followed by
“aggressive patrol” and the
formation of INTELLIGENCE partnerships with beat officers; some districts used flat-screen televisions in their roll-call rooms to display photos and convey other intelligence gathered on these prolific offenders to all district personnel.
(the future: I-Phone ICT app for facial-recognition?)

22. 50% Reduction in Serious Violence Rates in “Hot Spots”
20 Offender-Focus (O.F.) Hot Spots, 7 controls, 12 weeks
More Patrol, POP: NO REDUCTION
NOT NUMBERS of CONTACTS: equal frequency
MORE TARGETED: who was stopped?
More LEGITIMATE?
Only known bad guys
NOT indiscriminate stopping
NO Displacement surrounding areas

23. Transparency in Journals?
Complex statistical analyses
No raw numbers of crimes
Unfamiliar tests
No way to explain except “half as much”

24. Turning Point Project: Offender-Desistance Policing
Peter Neyroud
Jamie Hobday
Molly Slothower
Et al
Deferred Prosecution
Offer to have NO record
As carrot for compliance with immediate treatment
Prosecution a 6-month wait

25. Operation ‘Turning Point’
Sample: offenders whom the police have decided to prosecute, who are:
Low risk offenders
Who have no previous conviction (they may have previous cautions or other diversions)
or one prior conviction (more than 5 years ago if an adult and 2 years ago if juvenile).
And offence is not likely to result in instant prison sentence
Randomly assigning them to prosecution or police offender management
Developing and testing a standard protocol of tactics for police offender management

26. The Turning Point Experiment
Sample of 400 offenders whom the police have decided to prosecute
Random assignment=400
Prosecution = 200
Turning Point =200
Comparing like with like: Measure Which has less crime? Cost?, victim satisfaction

27. Crime Types—Turning Point

28. Control: court results

29. Control v Treatment initial failures rates
Court non-appearance
25%
Turning Point breach rates
25% v

30. Evaluating Turning Point?
If TPP can achieve same results or better
At lower cost
With no risk of increased harm
Police have evidence for deciding not to prosecute
Manage volume with legitimacy
But only if Victims Believe in It

31. Birmingham Turning Point Hypotheses:
Drawing on past research:
Victims will be happy with out of court disposals as long as they feel the police respect them, care about them, and are doing something in their interest
How police explain the outcome will matter: reducing reoffending as a legitimate police goal
Molly Slothower

32. Sample
142 Victims of cases randomly assigned to proesecution or Turning Point over a 6-month period
70% response rate in both TPP and prosecution
Both conditions explained
TPP description emphasized prevention, rehabilitation

33. “Satisfied” or “Very Satisfied” 46% increase for TPP

34. The Big Difference?
Turning Point sample was more likely to think what happened in their case is going to stop the offender from doing it again.
…effect was not likely without attention to communication

35. Percent Victims Satisfied With Decision

36. Electronic Tagging in Hants.
Paul Bartolomeo
Successful experiment
Voluntary Tagging
Offenders after short prison
Would not use
Could not use
Falsified Proof of Concept
Useful Knowledge!

37. Places: Targeting & Testing
Harm Spots: Cristobal Weinborn
Illegitimacy Hot Spots: Alex Murray

38. Targeting Hot Spots: Crime, Harm, Demand
Counts of crime
At same units of analysis
Whether addresses, intersections, street segments
Regardless of crime types selected
All crimes are created equal?
Showing probability of encountering any crime of that type (or types)

39. Why Crime COUNTS? Are all crimes created equal?
Aren’t some more serious than others?
Does the prescribed sentence length indicate it?
Canada—Crime Severity Index (2009)
Cambridge Crime Harm Index (2007)

40. Defining “Harm” Spots Prescribed penalties for crimes
Common currency of days in prison
Sentencing Guidelines,
Any state; or a national average
Each AND ALL crime types
In each unit of analysis
In the following graphics,
Unit of analysis = street segments
One street from one intersection to the next

41. Hot Spots of Birmingham--counts

42. CHI “Harm Spots”—same scale

43. What’s The Difference?
Hot Spots are less concentrated than harm spots—they cover more area of land
Harm spots are taller than hot spots
More of the harm in Birmingham is concentrated into less land than the same percentage of crime counts
Police can target fewer places, less space, with for more harm reduction using harm spots than by using hot spots.

44. Hot vs. Harm Spots

45. Inside Hot Spots: Special SEBP Issue of ICJR article
Slough
Non-domestic indoor violence
Houses of Multiple Occupation
Simon Bowden, Thames Valley
Violent crime 137 times higher in HMOs
Than in non-HMO dwellings
Most HMOs illegal

46. Hot Spots of Illegitimacy: CT Humint and Survey Data

47. How can police target with information already collected on DV ?
Best evidence to date: Suffolk UK (pop.730k).
Matthew Bland, Crime Analyst
Cambridge Mst thesis—brilliant job!
Analysis of 36,000 DV police callouts between 2009 and 2014.
Matthew Bland

50. Many and few callout cases
Most dyads (76%) had only 1 report in 5 years
BUT they had 54% of all harm, i.e. police have no priors recorded for over half of cases involving harm—and no subsequents

52. Crime Harm Index (CHI) Number of days imprisonment by offence type
Multiply Number of offences X days in jail
Not actual, but sentencing guideline
Social judgement of seriousness of crime

53. ‘Power few’ findings
Half of all repeat offenders offended against multiple victims
30% of all repeat victims were victimised by more than one offender
80% of all CHI harm occurred in < 2% of all dyads (412 of 24K cases)
Over half (53%) of the cases contributing to this 80% had just one reported event.

54. Volume of Domestic Violence Couples by Serious Harm (Sentencing Guideline Prison Days if Convicted)
Highest Harm 2% of Dyads
Medium Harm 18% Of dyads
Low Harm 80% of dyads

55. Does offence seriousness escalate over time?
Most dyads show no escalation in CHI harm
The tiny fraction who reach four callouts do show a sharp escalation in seriousness.

59. What we can learn about Targeting Domestic Violence:
Differentiate levels of harm
Look for a “power few” that drive the total harm levels
Target police resource allocation to do the most good with limited tools and time

60. Broader lessons: Stop treating DV as a ‘unitary’ phenomenon
Recognise that:
it covers a wide range of seriousness;
some victims are repeatedly victimised;
some offenders offend against multiple victims.
Remembering that police can only act on reported incidents, we cannot assume these are the only incidents: multi-agency approaches needed to identify “hidden” cases before first, high-harm events?
Think about ‘segmenting’ DV so that different policies and interventions can be applied for different kinds of case

61. Evidence-Based Policing of Domestic Abuse 2015
Heather Strang
Cambridge University

62. Targeting Domestic Abuse
A story about segmenting complex behaviour -
Differentiating levels of harm
What works for whom?

63. Domestic Violence Couples by Crime Harm Index (Sentencing Guideline Prison Days ) Bland, 2015
80%
Total
CHI
Days
Highest Harm 2% of Dyads
Medium Harm 18% Of dyads
Low Harm 80% of dyads

64. Testing Police Responses to DA
Southampton CARA Project (Hants) –
Low harm, high volume
Bracknell Forest (Thames Valley) –
Medium harm, repeat offending
Merseyside –
High harm, repeat offending

65. Southampton, Hampshire: ‘CARA’ conditional cautioning program
Target is
low-serious incidents (and strict CPS evidence test)
Adult male offenders
who admit the offence
No violence preceding 2 years
Spousal incidents only
Victim indicates no safety risk through this disposal

66. Random Assignment: Two Types of Caution
Good Behaviour Only
4 months
No more Domestic Abuse
Then no prosecution
Criminal Record shows caution
Conditional Caution/ Workshops
Held in a hotel by Hampton Trust
Two Sessions
3 weeks apart
Saturday mornings
3 hours each
All-male group
Discuss domestic abuse issues
‘Motivational’ techniques
e.g. What would your kids say?
Not directive
Encourage understanding DA
Final session: set a goal for DA

67. Partnership Effort
Cambridge Heather Strang Lawrence Sherman Barak Ariel
HAMPSHIRE POLICE Alex Marshall Robin Jarman Scott Chilton Jo Rowland Nicky Cornelius Rob Braddock Tony Rowlinson

68. Data So Far UK’s Longest-Running Police Experiment?
137 weeks and still randomizing cases
256 cases randomised to date via Cambridge ‘Randomiser
185 cases have at least 12 months reoffending data
96 Controls (Conditional Caution alone)
89 CARA cases (CC + Hampton Trust Workshop)

69. X2=3.131; p=.077
54% Reduction
(20/96)
(10/89)

70. X2=4.342; p= % reduction
(16/96)
(6/89)

71. X2=1.789; p=.181
(6/96)
(2/89)

72. X2=0.646; p=.421
(7/96)
(4/89)

73. 54% Fewer charges in DV Workshop Group (P = .028; Poisson distribution)

74. 72% Fewer Non DV charges in DV Workshop Group (P =
72% Fewer Non DV charges in DV Workshop Group (P = .006; Poisson distribution)

75. 29% Fewer DV arrests in DV Workshop Group (P =
29% Fewer DV arrests in DV Workshop Group (P = .294; Poisson distribution)

76. 64% Fewer Non_DV arrests in DV Workshop Group (P =
64% Fewer Non_DV arrests in DV Workshop Group (P = .091; Poisson distribution)

77. Promising but for Whom?
To get the 256 cases so far randomly assigned, 5562 cases assessed for eligibility so far.
In catchment area between 25 and 40 DA cases each week
About 50% are charged and about 50% NFA.
Caseflow averaging 1.86 cases per week.
What needs to happen to get more non-charged cases? – and not just in Hampshire.

78. Bracknell TVP DA Experiment
Multi-agency services for both victims and offenders, but separately.
Eligibility based on risk and frequency of calls – the most persistent cases.
At least 6 months post-RA reoffending data now available.

79. Bracknell Results so far:
Raw count of repeats similar for E and C
but
Major reduction in serious harm in E group after treatment but
More harm in E group during treatment - mainly more RO breaches – treatment effect?
Results so far ambiguous but promising –
Need more cases and more follow-up time.

80. Merseyside Police Experiment: Chronic Offenders
Police rank-ordered persistent DV offenders by frequency in callouts
Selected ‘top 200’ offenders
Randomly assigned 100 to experimental treatment:
Police contact them, preferably face to face
Inform them they are under close surveillance: any offence will be charged
Close contact and monitoring of victims by DV women’s support group
Outcome measure will be comparative DV reoffending

81. What Works For Whom? Different Effects on Different People
Different N of priors
Different Harm Levels

82. Totally-Evidenced Policing
British Transport Police EBP, Analysts Trained
Western Australia Police—EBPU, 100 trained
Durham Police—EBPU
Trinidad & Tobago—500 trained out of 6,000
Uruguay Police—300 trained

83. Governmental Use of EBP 2015
Professor Laurie Robinson, George Mason U.

84. Legitimacy, Procedural Justice, and Police Body-Cams
Dr. Barak Ariel

85. Lawrence W. Sherman Heather Strang Cambridge University
THANK YOU!
Lawrence W. Sherman
Heather Strang
Cambridge University