1. Peter Neyroud CBE QPM University of Cambridge
Offender Desistance Policing? Presentation for the 4th International Evidence Based Policing Conference
                                                                                                                                                                                  
Peter Neyroud CBE QPM
University of Cambridge

2. Overview An outline of the theory
Turning theory into practice: a programme of experiments
The implications for practice

3. Context Pressure on criminal justice budgets
Renewed emphasis on prevention and rehabilitation

4. Life course criminology
Growing understanding from key work such as the prizewinners, Sampson and Laub
Desistance as a process with turning points
Opportunities to focus on encouraging desistance amongst the known offenders
Particularly the “power few” who are persistent
But also to prevent others joining them

5. Crime Harm Forecasting
Since Meehl 1954 Clinical Versus Statistical Prediction
Statistical Prediction beats Clinical
Most contests before statistical learning
Cheap supercomputers
“Data mining” that assays every possible pattern of precursors
Identifies best prediction combinations

6. New Generation of Risk Forecasting
Based only on Prior Charges, Residence, Age, Sex—no PSR
Nothing qualitative
More like a short-term weather forecast
Based on huge samples
E.g., 30,000 in Philadelphia
Journal Royal Statistical Society, Series A, 2009
Richard Berk

7. Neither High nor Low Risk (38%)
Geoffrey Barnes (2007) 2-Year Berk Forecast Test, Philadelphia APPD Cases
High Risk (2%)
Neither High nor Low Risk (38%)
Low Risk (60%)

8. Effects of Prosecution and Prison on recidivism
“almost all of the results are negative in direction, as measured by prevalence, incidence, severity, and self-report outcomes.” Petrosino et al. (2010)
“Growing research evidence suggests that for many if not most people put in prison for the first time, the net effect of prison may be to cause more crime than if the sentence had not been custodial” Sherman and Neyroud (forthcoming)
The deterrent effects of Prosecution and Incarceration are balanced by potentially negative treatment effects, particularly for first time entrants

9. Certainty and Celerity not Severity: a cause for HOPE?
Operation HOPE focused on recidivist drug offenders
Emphasis on certainty of punishment if treatment conditions breached
Trial showed a near halving of overall incarceration rate
HOPE is being replicated in 2 mainland sites and results appear consistent
HOPE appears to be effective with lower risk offenders

10. Offender Focused policing
Police can replicate many of the preventive effects of HOPE but before prosecution
For example, Restorative Justice experiments (Sherman and Strang) demonstrated positive effects in reducing violent reoffending (less effective with property offenders

11. The Sword of Damocles
2 Experiments in Omaha, Nebraska testing different approaches to domestic violence (Dunford et al. 1990).
“These experiments found that the mere issuance of a warrant for an offender’s arrest had a greater deterrent effect than actually arresting the offender”
The more general form of this proposition is that by communicating more certainty that some action will be taken, police may able to prevent many offences from occurring

12. A Programme of experiments
Stage One: constructing a Crime Harm Index
Stage Two: First Time Offender diversion to offender desistance policing
Stage Three: applying the CHI as a triage tool in police custody suites
Stage Four: testing which tactics produce the best

13. The Crime Harm Index
A random sample of 100,000 records from the UK Police National Computer’s Phoenix criminal records database
Produces over 3,000,000 data items about the 100,000 offenders
Replicating Berk’s model with the larger database
Using statistical analysis to model the factors predicting serious harm

14. First Time Offender trial
Taking a sample of offenders whom the police have decided to prosecute
Who have no previous conviction (they may have previous cautions or other diversions)
Randomly assigning them to prosecution or police offender management
Developing a standard protocol of tactics for police offender management linked to “sword of Damocles” approach

15. A Triage tool for custody officers
From the CHI work with the Police National Computer, developing a triage tool to guide custody decisions about investigation, prosecution and diversion
Applying that tool in a further trial linking police offender management to CHI triage
Measuring the outcome against an index of crime harm

16. Testing the tactics
In the later trials, testing the relative benefits of different elements of the protocol of tactics against each other
Matching interventions more effectively to offenders
Experimenting with Community, volunteer and other agency support for the tactics

17. Conclusions
“It is entirely possible that all of these tactics could fail to foster desistance from crime, even though the strategy of diversion or harm-forecasting could work nonetheless. There may be more general validity finding by Petrosino and his colleagues (2010) that doing nothing with juveniles was better than doing something, at least in terms of repeat offending. Yet it is very difficult to reconcile doing nothing with deeply held moral values for holding offenders accountable. Whatever works in terms of helping offenders desist should also be seen as a form of justice, one by which offenders must pay a price.” Sherman and Neyroud, forthcoming