Dr Jenny Maresh An agent-based simulation model of the Criminal Justice System of England and Wales

Dr Jenny Maresh

An agent-based simulation model of the Criminal Justice System of England and Wales

www.cjsonline.gov.uk

Talk Plan

•Introduction

•Criminal Justice System and the Office of Criminal Justice Reform

•Brief History of the CJS Model

•How the model works

•Recent projects completed using the model

•Challenges ahead

•Other modelling work carried out in OCJR


Introduction

• At the 2003 Justice Modelling Workshop Paul Henderson presented a simulation model of the Criminal Justice System of England and Wales.

• This model has now been in use for two years.

• In this talk I will give a progress report on how this model has been used, and where it stands now as a tool for policy planning and budget allocation in the Criminal Justice System of England and Wales.


Talk Plan

•Introduction





•Challenges ahead



Court of Appeal

Crown Court

Attorney General’s Office

Home Office

Crown Prosecution

Service

Legal Aid Cost of defence

lawyers in criminal

cases

Magistrates' courts

Police Services43 Local Forces

National Offender Management Service

Department of Constitutional

Affairs

Judiciary and

magistracy

Court Service

Legal Services

Commission

National police

functions

Local authorities

Local Criminal Justice Boards

Local Police Authorities

Youth Justice Board

Serious Fraud Office

Other prosecuting agencies

National Criminal Justice Board


Breakdown of CJS Expenditure 2005/6

Police57%

Correctional Services21%

Youth Justice Board2%

Home Office4%

Prosecutions3%

DCA1%

Criminal Courts4%

OCJR2%

Legal Aid6%

Total expenditure = £18.94 billion


What is the Office for Criminal Justice Reform?

The Office for Criminal Justice Reform is the cross-departmental team that supports all criminal justice agencies in working together to provide an improved service to the public.

It is a fully shared resource, reporting on an equal basis to the Home Office, Department for Constitutional Affairs and Law Officers’ Departments.


What does the OCJR do?

• Bring more offences to justice (cross-CJS PSA)

• Raise confidence in the criminal justice system (cross-CJS PSA)

• Support and co-ordination of performance management for Local Criminal Justice

Boards

• Support for the National Criminal Justice Board

• Management of the CJS Spending Reviews

• The CJS Information Technology programme

• Support for victims and witnesses

• A programme of work to improve cross-agency work on enforcement of court

orders

• Co-ordinating implementation of the Criminal Justice Act


Talk Plan

•Introduction





•Challenges ahead



History of modelling the Criminal Justice System

1980s Unsuccessful attempt to model the CJS – approach too complex for the available technology (Morgan 1985)

1993-2003 Flows & Costs Model• Shared data from three agencies, but issues over quality

and compatibility

• Costs not fully accepted by DCA & CPS, so used in SR02 to assess downstream impacts of policies only in terms of workload, not costs

• Further development of a CJS model was stipulated in the SR02 settlement letter


Birth of the CJS Model

• A survey of models across the CJS departments unearthed 22, with many being highly specific and localised, no broader coverage

• We required a model to assess the impact of policy generated in one CJS area on the other parts of the system

• ‘Agent-based’ approach. The process has been used successfully in a range of situations outside the CJS

• Resources and costs agreed by all the agencies involved

• The new model was commissioned and built during 2003


Benefits of the CJS Model

• Allows consideration of capacity constraints and bottlenecks in the system

• Outcomes become emergent properties of the system, allowing unforeseen consequences to be evidenced as well as those expected

• Improved information on the workings and attributes of the real CJS can be incorporated, and the impact evaluated


Who can use the CJS Model?

Criminal Justice System

Agencies:

• Police Forces

• Court Service (MC & CC)

• Crown Prosecution Service

• Legal Services Commission

• National Probation Service

• Prison Service

Criminal Justice System Departments:

• Office for Criminal Justice Reform

• Home Office

• Department of Constitutional Affairs

• Office of the Attorney General

Other Bodies:

• Prime Ministers Delivery Unit

• Local/National Criminal Justice Boards

• HM Treasury


Who can use the CJS Model?

• The CJS Model is a policy planning tool available for use throughout the CJS

• HM Treasury stipulate that any CJS legislation with financial implications must be run through the model. Spending reviews.

• We would like modelling and planning units in the CJS departments and agencies to use the model themselves

• This isn’t really happening at the moment though

• We run regular cross-CJS training courses

• We are the custodians of the model, maintaining it as ‘fit for purpose’ and Quality Assuring any analysis performed using the model by others


Talk Plan

•Introduction





•Challenges ahead



Data Inputs

CJS Model

Criminal Statistics

British Crime SurveyCJS agencies data on resources, activities and costs.


How does the model work?

COURTS

POLICE

Recorded Crime

Arrest

Summons

TICCharge Cautions

No further action

CPS proceedingsLegal Aid proceedings

Discontinued

AcquittalDiscontinued

ProbationPrison

Actual Crime

LEGAL AID CPS

Magistrates Court

Crown Court

CustodialOther

DisposalFineCommunity

Remanded incustody

CORRECTIONS

Unsolved

Unreported

People/cases flow through the model according to assigned probabilities

Resources are consumed (e.g. policemen, judges, probation officers) while carrying out activities

Activities take time

If no resources are available, queues develop

The model allows us to look at populations, durations for processes, costs of cases etc.


COURTS

POLICE

Recorded Crime

Arrest

Summons

TICCharge Cautions

No further action


Discontinued


ProbationPrison

Actual Crime

LEGAL AID CPS

Magistrates Court

Crown Court

CustodialOther


Remanded incustody

CORRECTIONS

Unsolved

Unreported


COURTS

POLICE

Recorded Crime

Arrest

Summons

TICCharge Cautions

No further action


Discontinued


ProbationPrison

Actual Crime

LEGAL AID CPS

Magistrates Court

Crown Court

CustodialOther


Remanded incustody

CORRECTIONS

Unsolved

Unreported


COURTS

POLICE

Recorded Crime

Arrest

Summons

TICCharge Cautions

No further action


Discontinued


ProbationPrison

Actual Crime

LEGAL AID CPS

Magistrates Court

Crown Court

CustodialOther


Remanded incustody

CORRECTIONS

Unsolved

Unreported


COURTS

POLICE

Recorded Crime

Arrest

Summons

TICCharge Cautions

No further action


Discontinued


ProbationPrison

Actual Crime

LEGAL AID CPS

Magistrates Court

Crown Court

CustodialOther


Remanded incustody

CORRECTIONS

Unsolved

Unreported


COURTS

POLICE

Recorded Crime

Arrest

Summons

TICCharge Cautions

No further action


Discontinued


ProbationPrison

Actual Crime

LEGAL AID CPS

Magistrates Court

Crown Court

CustodialOther


Remanded incustody

CORRECTIONS

Unsolved

Unreported


COURTS

POLICE

Recorded Crime

Arrest

Summons

TICCharge Cautions

No further action


Discontinued


ProbationPrison

Actual Crime

LEGAL AID CPS

Magistrates Court

Crown Court

CustodialOther


Remanded incustody

CORRECTIONS

Unsolved

Unreported


CJS Costs

• So far we have discussed the flow of people through the model and interaction with resources, but not costs.

• We input hourly costs of resources into the model (and overheads).

• The model calculates resource utilisation due to capacity of the CJS and hence the productivity costs which can be used for planning.

• We are planning to add functionality to the model to output figures such as fully loaded cost of a trial, cost to the CJS of a case thrown out due to lack of evidence.


Talk Plan

•Introduction





•Challenges ahead



Recent Projects

Long Term Strategic projects

• Forecasting prison projections including the effects of the Criminal Justice Act 2003 for National Offender Management Service

• Examining the impacts of falling crime and increasing police detections on capacity within all areas of the Criminal Justice System

Short Term Tactical projects

• The impact of industrial action of lawyers on Offences Brought to Justice (a PSA target), remand prison population and length of justice process.


Talk Plan

•Introduction





•Challenges ahead



Model Flexibility

Therefore the model requires long term investment in maintenance, development and publicity.

We can investigate the costs of processes and flows through any part of the CJS. Durations of processes by any grouping of offence types/gender/age.

The model is modular allowing it to be updated as the CJS changes.

However this means that …

The model has not been designed for any one project, so it is not perfect for any individual piece of work.

Its greatest strength is also its Achilles heal


Maintaining confidence amongst Policy Makers

•Quality Assuring the model

•Producing timely and targeted outputs

•Publicising the model within the CJS

•Making the model easy to use so that Policy people can understand how it works

•Continually developing model to keep up with changes in the CJS


The way forward – development priorities

•Maintaining the model as representative of the real world CJS• Adding new sentences available through the Criminal Justice Act 2003

•Improve the modelled processes• Link up rehabilitation to reoffending rates and hence annual crimes.

• Add prioritisation for resources carrying out activities

•Increase flexibility of outputs and make more user friendly• Customised output files• Interactive running of the model• Combined data & model installation


Talk Plan

•Introduction





•Challenges ahead



Other Modelling work carried out in OCJR

Smaller static models which fit into the broad framework of the CJS Model

• OBTJ Model – producing trajectories for the Offences Brought to Justice Target


OBTJ Model producing trajectories


Other Modelling work carried out in OCJR

Smaller static models which fit into the broad framework of the CJS Model

• OBTJ Model – producing trajectories for the Offences Brought to Justice Target

• London Model• No plans to regionalise CJS Model at the moment• London Model – OBTJ & Courts Demand

Dr Jenny Maresh

An agent-based simulation model of the Criminal Justice System of England and Wales

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Dr Jenny Maresh An agent-based simulation model of the Criminal Justice System of England and Wales