1

Crime Data Sources

Police reports, victimization, and self-report data

2

Sellin’s Dictum

“The value of a crime for index purposes decreases as the

distance from the crime itself in terms of procedure increases”

Thorsten Sellin, 1931

3

Sources of Crime Statistics

• Uniform Crime Reports (UCR)

• National Crime Victimization Surveys (NCVS)

• Self-Report Data (SRD)

4

Uniform Crime ReportsPart 1 Offenses

• “Serious illegal acts that occur with sufficient frequency to provide an adequate basis for comparison”

5

Crimes Not Included in the UCR Part 1 Crime Index

Reason: they do not come to the attention of police often enough.

6

Becoming a UCR Crime Statistic• Step 1:

• Step 2:

Police must decide…

• Step 3:

• Step 4:

7

Reporting Crimes to the Police

• People are MORE likely to report if…

• People are LESS likely to report if…

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Officer Discretion

• Officer discretion influenced by offense and offender characteristics

9

Recording of Crimes by Police

• Characteristics of the offense

• Characteristics of offender

• Characteristics of the victim

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Strengths of the UCR• National

• Permits comparisons

• Links to other sources

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Weaknesses of the UCR• Street crimes

• Reactive crime reporting by citizens

• Officer discretion

• Susceptible to political pressure to over or under-report

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The National Crime Victimization Survey (NCVS)

• Conducted by the U.S. Bureau of Census every 6 months, households remain up to 3 years

13

Self-Report Data

• Unofficial statistics

• Gets at the “dark figure” of crime

• Provides information on causes of crime from offender’s perspective

14

Ethical Issues in Self-Report Studies of Violent Crime

• Exchange confidentiality for honesty

• Ask subjects not to talk about planned violence