© 2001 Vito & Blankenship. Learning Objectives In this chapter you will learn role of statistical...


Learning ObjectivesIn this chapter you will learn

role of statistical analysis in criminal justice

how crime in measured in the U.S.strengths & weaknesses of crime

measuresapplication of statistical analysis in a

criminal justice agency


Introduction

Studying statistics can be important to yourunderstanding of the disciplineprofessional developmentcareerrole as a consumer and a citizen


Validity of Crime StatsValidity is synonymous with

accuracyAre the ways we measure crime

valid?What are the implications for the

use of crime statistics in planning?


Ways of Measuring Crime

Two major ways of measuring the amount and types of crimesUniform Crime Report (official data)

changing to National Incident-Based Reporting System

National Crime Victimization Survey


Uniform Crime Report Crime in the United States

collected and reported by the police to Federal Bureau of Investigation since 1930

highlights Part I or Index OffensesThe Crime Index

Murder, Rape, Robbery, Assault, Burglary, Larceny-Theft, Motor Vehicle Theft, Arson


Reported Crimes, 1996

7.4 36.1 202.4388.2

943

2975.9

525.9

0

500

1000

1500

2000

2500

3000

MurderRape

RobberyAssaultBurglaryLarcenyVehicleTheft

Part I Crimes per 100,000


Limitations of the UCROnly reflects the volume of crime

reported to the policeAffected by the recording practices

of the policeEmphasizes street crime. No

statistics on white-collar crimeFigures reflect the style of of police

work


Strengths of the UCRThe major source of crime

statistics in the USPolice and citizens agree on

what constitute a serious crime“Unfounding”: how the UCR

verifies the data


National Crime Victimization Survey

Conducted by the Bureau of Justice Statistics since 1972, the NCVSattempts to uncover unreported

crime; surveys 60,000 households.takes information directly from victimscollects background information on

victims


UCR & NCVS CrimeType of Crime UCR NCVS

Rape 95,770 98,000

Robbery 537,050 1,134,000

Assault 1,029,810 1,910,000

Burglary 2,501,500 4,845,000

Larceny-Theft 7,894,600 21,120,000

Motor Vehicle Theft

1,395,200 1,387,000

TOTALS 13,453,930 30,494,000


NCVS Rates, 1996

0.45.2

35.4

47.2

205.7

7.7

0

50

100

150

200

250

Rape Robbery Assault Burglary Larceny-Theft Motor Vehicle Theft


Limitations of the NCVSAccuracy: Forgetting and “telescoping”

are potential problemsLying: Concealing victimizations due to

embarrassment or overreporting to please the interviewer

Asks questions about rape in an indirect manner


Limitations of the NCVSProblems in administration and codingSurvey represents nation as a whole,

does not contain specific information on one area

Tends to overrepresent non-serious crime


Why Crime Not ReportedReasons for not reporting crime

Violent crimespersonal or private matter and the offender was not successful

Theftproperty recovered, offender not successful, reported to some other official, lack of proof.household crimes: same as theft, plus police would not want to be bothered.


Why Report Crime?

Violent Crimesto prevent future crimes by the

offenderto stop or prevent the crimebecause it is serious


Why Report Crime?

Theftto recover stolen propertybecause it was a crimeto collect insuranceto stop or prevent the incident


Advantages of CFS DataGatekeeping procedures of the police

are bypassed. Computers record every call

Interviewer, sampling and memory bias are not a problem

Police arrest statistics are often biased by place and status of the offender


Weaknesses of CFS DataA complaint must be made

before it can be recorded by the system

Overreporting can occurOffense location not always

included


Routine Activities TheoryElements of Routine Activities Theory: A motivated offender; A suitable target; The absence of a capable guardian to

prevent crime Crime control

prevent convergence of offenders and targets without guardians


The Compstat Process

Accurate and timely informationWhat type of crime is it?Where is crime occurring?When is crime happening?Why is crime happening?


Rapid deployment of resourcesEffective tacticsRelentless follow-up and

assessment

The Compstat Process


Results

The Compstat Process leads to:enforcement strategies to target

specific crimes or conditionsRefocusing the strategy of community

policing giving Precinct Commanders

authority and responsibility


Crime Reported to NYPDType of Crime

1996 1997 % Change

Murder 984 767 - 22.1%

Rape 2888 2788 - 3.6%

Robbery 49324 44339 - 10.1%

Assault 30615 30259 - 1.2%

Burglary 61986 54860 - 11.5%

Grand Larceny

58690 55670 - 5.2%

Auto Theft 59465 51330 - 13.7%

TOTAL 263,952 240,013 - 9.1%


Misuse of Data

Steps to prevent misuse of crime statisticsobtain data over as many data

points and years as is feasibleincrease the number of indicatorsuse current data


SummaryImportant to understand

limitations of researchStatistics can provide basis for

rational decision making ifvalidrelaible

© 2001 Vito & Blankenship. Learning Objectives In this chapter you will learn role of statistical...

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