1. Criminal Violence Riedel and Welsh, Ch. 2 “Measures of Violence”

2. OUTLINE I. Why Are Measures Of Crime Important?
II. Crime Rates v. Amounts
III. Three Types of Crime Data
Uniform Crime Reports (UCR)
National Incident Based Reporting System (NIBRS)
National Crime Victimization Survey (NCVS)

3. I. Why Are Measures Of Crime Important?
We need reliable data about violent crime in order to inform:
(a) Public policy (e.g., responses to crime)
(b) Research about violence (e.g., patterns, causes, and interventions).
Translational Criminology: A Message from the Director of NIJ
Each source of data has its strengths and weaknesses. None is perfect.
To be able to use and understand crime measures, it is necessary to be aware of major strengths and weaknesses.
Translational Criminology: A Message from the Director [Published on Mar 6, 2012]
This is the third in a series of conversations with John Laub, Ph.D., Director of the National Institute of Justice. Dr. Laub discusses "Fusing NIJ's Dual Mission Through Translational Criminology," "Questions That Guide NIJ's Approach to Translational Criminology" and "The Role of 'Trust' in Translational Criminology."

4. Q: is violent crime going up or down? A: Answer depends on:
We need to be able to distinguish “opinions” from “evidence” (review Ch.1 -- “social construction”)
Q: is violent crime going up or down?
A: Answer depends on:
1) The type of measure used,
2) The type of crime,
3) The time period,
4) Use of rates v. raw numbers.

5. II. Crime Rates v. Amounts
The amount of violent crime refers to the total number of incidents within a specific location and time span.
Crime rates are ratios of crime incidents to the total population.
Crime rates have five components:
amount of the crime;
population at risk for that crime;
a constant multiplier such as 100,000;
location; and
time span.
Crime Rate = (Amount / Population at Risk) X 100,000

6. Crime Rates v. Amounts (cont.)
Example:
There were 510 murders in Chicago and 523 murders in New York in Which city had the greatest risk of murder victimization?
If we “plug in” the numbers, we have the following 2008 murder victimization rates:
(New York) = (523/ 8,345,075) * 100,000
(Chicago) = (510/ 2,829,304) * 100,000
Persons living in Chicago have a risk of being murdered that is 3 times higher than the risk for people living in NY.
While the amount of murders for the two cities is similar, the rate of victimization is dramatically different.

7. III. Three Types of Crime Measures 1. Uniform Crime Reports (UCR)
There are over 17,000 city, county, and state law enforcement agencies reporting to the UCR program directly or through state agencies.
Part I offenses (“Index” offenses) are divided into crimes against the person (criminal homicide, forcible rape, robbery, aggravated assault and arson) and crimes against property (burglary, larceny-theft, motor vehicle theft.
Part II offenses include 21 other offenses such as fraud, embezzlement, weapons offenses, and simple assault.

8. Uniform Crime Reports (cont.)
While a number of forms are required by the UCR program, three are most relevant to violent crime:
Return A: Crimes Known to Police
Age, Sex, Race, and Ethnic Origin of Arrested Offenders; and
The Supplementary Homicide Report.
The process of collecting information about violent crime begins with a complaint to law enforcement officials who investigate and determine whether a criminal offense has occurred (see Fig. 2.1).

9. 2. National Incident Based Reporting System (NIBRS)
The UCR has been subject to criticism from the 1950s onward.
NIBRS was created to address several limitations of the UCR.
Q: What are some of the limitations of the UCR?
The National Incident-Based Reporting System (NIBRS) goes beyond the simple summary counts of eight offenses presently collected under the Federal Bureau of Investigation's (FBI) Uniform Crime Reports (UCR) and represents a more sophisticated system of incident-based data collection that enables state and local jurisdictions to capture detailed offense, offender, victim, property, and arrest data concerning each crime incident. The broader scope of offense and offender characteristics permit the development of policy-relevant findings describing the nature and characteristics of crimes, such as gun assaults, domestic violence, hate crimes, and crimes against children.
In addition to changing the fundamental reporting structure underlying crime and arrest information, NIBRS expands the range of offenses for which data is identified to include 22 crime categories, spanning 46 offenses. This contrasts with the current summary UCR, which captures only general offense and arrest information on the 8 UCR Index offenses (murder, rape, robbery, aggravated assault, burglary, larceny, motor vehicle theft and the recently added arson) and only general characteristics of persons arrested for a limited range of other offenses.
Because NIBRS provides more comprehensive data on a wider range of offenses, it will permit law enforcement executives, analysts, and the public to better understand trends in different types of crime and the harm to victims. Jurisdictions that have implemented incident-level reporting systems are more capable of utilizing crime data for strategic planning, tactical crime analysis, and manpower deployment. This potentially results in more effective utilization of limited resources and implementation of crime control strategies.

10. UCR v. NIBRS

11. 3. National Crime Victimization Survey
The National Crime Survey began in In 1991, the National Crime Survey was redesigned and retitled the National Crime Victimization Survey (NCVS).
Crime surveys, unlike information collected from police, rely on interviews with victims.
One purpose of crime surveys is to get an idea of how much crime occurs that is not reported to or by the police.
Crime rates estimated by the UCR are only about one-half to one-third of those based on victim reports.

12. How are Incidents Collected?
NCVS (cont.)
How are Incidents Collected?
The NCVS collects victimization data from a nationally representative sample of about 100,000 individuals age 12 or older living in about 50,000 U.S. households.
Interviews are translated for non-English speaking respondents.
The interview takes about ½ hour.
What is Collected?
There are two steps in interviewing victims:
Screening questions: determine whether the respondent has been the victim of a crime in the past four months;
If the respondent indicates that someone in the household has been a victim, then an individual victimization report is completed for each incident mentioned.

13. NCVS (cont.)
In addition to estimating the number of incidents, the NCVS gathers details about each incident:
Characteristics of the victim (age, sex, race, ethnicity, marital status, income, and educational level),
Characteristics of the offender (sex, race, and approximate age),
Relationship between victim and offender,
Month, time, and location of the crime,
Self-protective actions taken by the victim during an incident and results of those actions,
Consequences of the victimization, including any injury or property loss,
Whether the crime was reported to police; reasons for reporting/not reporting, and
Offender use of weapons, drugs, and alcohol.

14. NCVS (cont.) - Limitations
Cost of Large Samples. To get reliable estimates, a very large number of people must be sampled.
Poor Memory and Telescoping. The longer the time between the actual victimization and the interview, the greater the likelihood of memory failure. There is a danger of telescoping: a victimization that occurred outside the requested time span is mistakenly recalled as occurring within the last six months.
Errors in Reporting:
Mistaken reporting: respondent believes he or she was the victim of a crime but they were not.
Sampling Bias. Potential undercounting of young people, males, and members of minority groups.

15. COMPARISONS BETWEEN THE NCVS AND THE UCR
The two reporting systems are complementary: the strengths of one partially compensate for the weakness of the other.