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Statistics: Reporting Systems and Methods - Official Crime Statistics

police crimes data index

Contemporary official crime statistics, proliferating with the growth of crime-control bureaucracies and their need to keep records, are more comprehensive and varied than nineteenth-century judicial statistics and early twentieth-century police statistics. The purposes and functions of crime statistics have also changed. Whereas the early judicial statistics were utilized to measure a nation's moral health or the social and spatial distribution of crime, many of the more contemporary official statistics are the byproducts of criminal justice "administrative bookkeeping and accounting." For example, data are collected on such matters as agency manpower, resources, expenditures, and physical facilities, as well as on warrants filed and death-row populations. Consequently, in the United States there are hundreds of national—and thousands of state and local—sources of official statistics, most of which are best characterized as data on the characteristics and procedures of the administration of criminal justice and crime control.

Given the different histories of judicial and police statistics in Europe and the United States, it is not surprising that in the latter there are relatively good police data compiled on a nationwide annual basis and relatively poor judicial data. In fact, the United States is one of only a few developed countries that publishes no national court statistics. Reflecting the unique history of corrections in the United States, where the state prison and local jail are differentiated by jurisdiction, incapacitative functions, type of inmate, and record-keeping practices, there are relatively comprehensive annual national data on the number and characteristics of adults under correctional supervision in state and federal prisons, but no national statistics on jail populations are published. A review of sources of criminal justice statistics concluded, "the absence of regular annual data on jail inmates is, along with the absence of court statistics, the most glaring gap in American criminal justice statistics" (Doleschal, p. 123).

Official crime statistics measure crime and crime control. Clearly, the historically preferred source of official statistics on the extent and nature of crime is police data, particularly crimes known to the police. Other official data gathered at points in the criminal justice system that are procedurally more distant from the crime committed are less valid and less useful measures of crime. However, these data can serve as measures of the number and social characteristics of those who are arrested, prosecuted, convicted, or imprisoned; of the characteristics, administration, and procedures of criminal justice within and between component agencies; and of the socially produced and recognized amount and distribution of crime. Official statistics, except for data on crimes known to the police are more correctly regarded as measures of crime control because they record a social-control reaction, of the criminal justice system to a known offense or offender. For example, a crime known to the police typically reported to the police by a complainant, and the record of it is evidence of the detection of a crime. If the police clear the offense through arrest, the arrest record is evidence of the sanction of a criminal, a measure of crime control (Black). In other words, a crime known to the police registers acknowledgment of an offense; an arrest, of an offender; a prosecution and conviction of the offender. Arrest, prosecution, conviction, and disposition statistics as well as administrative bookkeeping and accounting data, are best thought of as information of the characteristics, procedures, and processes of crime control. The focus in this entry will be the official statistics of crime, specifically police statistics of offenses known.

A measure of crime: offenses known to the police. From the beginning, the primary objective of the Uniform Crime Reports was made clear in 1929 by the committee on Uniform Crime Records of the International Association of Chiefs of Police—to show the number and nature of criminal offenses committed. At the time it was argued that among the variety of official data, not only were "offenses known" closest to the crime itself, but a more constant relationship existed between offenses committed and offenses known to the police than between offenses committed and other official data—assumptions shown to be erroneous by victimization surveys many years later. Nevertheless the UCR have always been the most widely consulted source of statistics on crime in the United States.

The UCR are published annually by the F.B.I. and provide statistics on the amount and distribution of crimes known to the police and arrests, with other, less complete data on clearances by arrest, average value stolen in a variety of property offenses, dispositions of offenders charged, number of law enforcement personnel, and officers assaulted or killed. The statistics are based on data submitted monthly by the fifteen thousand municipal, county, and state law enforcement agencies, which have jurisdiction over approximately 98 percent of the U.S. population.

Of crimes known and arrests, data are collected in twenty-nine categories of offenses, using standardized classifications of offenses and reporting procedures. Crimes known and arrests are presented for the eight original "index crimes"–murder, rape, robbery, aggravated assault, burglary, larceny, motor-vehicle theft, and arson—and arrests only, for the remaining (non-index) crimes. Arson was added as an index crime in 1979. For each index crime, crimes known to the police are presented by number of crimes reported, rate per hundred thousand population, clearances, nature of offense, geographical distribution (by state, region, size, and degree of urbanization), and number of offenders arrested. Arrests are presented by total estimate for each index and nonindex crime, rate per hundred thousand population, age, sex, race, and decade trend.

The index crimes are intended to represent serious and high-volume offenses. The Total Crime Index is the sum of index crimes, and subtotals are provided on violent and property index crimes. The Total Crime Index, and to a lesser extent the violent- and property-crime indexes, are often used to report national trends in the extent and nature of crime.

The statistics presented in the UCR of crimes known to the police are records of "reported" crime, and since reporting and recording procedures and practices are major sources of methodological and utilization problems, they deserve further attention. Crimes known to the police are typically offenses reported to the police by a victim or other person and are recorded as such unless they are "unfounded," or false. For property crimes, one incident is counted as one crime, whereas for violent crimes one victim is counted as one crime. Except for arson, the most serious of more than one index crime committed during an incident is counted; arson is recorded even when other index crimes are committed during the same incident. For example, stealing three items from a store counts as one larceny, but beating up three people during an altercation counts as three assaults.

Larceny and motor-vehicle theft account for the largest proportion of index crimes, for reasons pointed to by critics. Both are the least serious of the index crimes, with larceny of any amount now eligible to be counted, and motor-vehicle theft having one of the highest rates of victim reports to the police because theft must be established to file for insurance claims. On the other hand, many crimes that could be considered more serious because they involve physical injury and bodily harm to a victim are not index crimes. Moreover, completed and attempted crimes are counted equally for more than half of the index crimes. Robbery is counted as a violent crime and accounts for almost one-half of all reported violent index crimes. Most other countries classify robbery as a major larceny, as did the United States before the inception of the UCR. Of course, this difference in classification explains in part the relatively higher rate of violence in the United States. A number of other serious offenses are not counted at all in the reporting program, including a variety of victimless, white-collar, and organizational crimes, as well as political corruption, violations of economic regulations, and the whole array of federal crimes. One might characterize the Total Crime Index as a measure of the extent, nature, and trends of relatively ordinary street crime in the United States.

There are also some problems in the presentation of these data. The Total Crime Index, as a simple sum of index offenses, cannot be sensitive to the differential seriousness of its constituent offense categories and to the relative contributions made by frequency and seriousness of offenses to any index of a community's crime problem (Sellin and Wolfgang). Rudimentary summations of data also mask potentially important variations among offenses and other factors. Comparisons of data from year to year, and even from table to table for the same year, may be hampered in some cases because data may be analyzed in various ways (for example, by aggregating data in different ways for different tables). Comparisons are also made difficult by the use of inappropriate bases (or denominators) in the computation of the rates that are presented both for crimes known to the police and for arrests.

The crime rates given in the UCR, as well as in most criminal justice statistical series, are computed as the number of crimes per year per hundred thousand population. This type of "crude" rate can lead to inappropriate inferences from the data. The use of crude rates can conceal variation in subgroups of the population, so it is desirable to standardize rates for subgroups whose experience is known to be different, for example, by sex, race, and age. These subgroup-specific rates also facilitate comparisons between groups: male-female rates, white-black rates, and juvenile-adult rates.

At times, inappropriate population bases are used in calculating rates. A crime rate represents the ratio of the number of crimes committed to the number of persons available and able to commit those crimes; this ratio is then standardized by one hundred thousand of whoever is included in the base. For some offenses, the total population is an inappropriate base. For example, a forcible-rape crime rate based on the total population is less appropriate than a rate based on the number of males available and able to commit rape. Similarly, the juvenile crime rate should reflect the number of crimes committed by the population of juveniles.

Crime rates can be interpreted as victimization rates, depending on who (or what) are included in the base. If the total population base can be considered potential criminals, they can also be considered potential victims. For crimes where the victim is a person, the calculation of surrogate victimization rates using crime data is relatively straightforward—the number of available victims becomes the base. Again, in the case of forcible rape, the total population and the male population would be inappropriate bases—here the population of available victims is essentially female. Therefore, the surrogate victimization rate would be calculated as the number of forcible rapes known to the police per hundred thousand female population.

For property crimes it is more difficult, but not impossible, to calculate surrogate victimization rates. Here the denominator may have to be reconceptualized not as a population base but as a property base. For example, Boggs, and later Cohen and Felson, included "opportunities" for property theft in the bases of their analyses, including, for example, the number of cars available to steal. They reported that the subsequent opportunity-standardized rates were very different from the traditional population-standardized crime (or victimization) rates. Opportunitystandardized rates may sometimes differ even in direction. For example, rather than showing the rate of motor vehicle—related theft increasing, a corrected rate showed it to be decreasing (Wilkins; Sparks). Ultimately, of course, much more precise victimization rates are available from victimization survey data.

Finally, the total population base may be used incorrectly if the decennial Bureau of the Census counts of the population are not adjusted for projected population estimates on a yearly basis. For example, if the 1990 census data are used in the base to calculate 1999 crime rates, the rates will be artificially inflated simply as a consequence of using too small a population base. Obviously, 1999 population estimates are more appropriate in the calculation of 1999 crime rates.

Overall, the data presented in the UCR are "representative." However, the greatest threat to the validity of these statistics is differential reporting to the F.B.I. by local police, within participating departments, and to local authorities by citizen victims or other complainants. There is underreporting both by and to the police.

The reports of participating law enforcement agencies to the F.B.I. can be affected in a variety of ways, leading to variations in the uniformity, accuracy, and completeness of reporting. In spite of efforts to standardize definitions of eligible offenses, police in different states with different statutory and operational definitions of offense categories may classify crimes differently. There may be internal and external pressures on police agencies to demonstrate reductions in community crime or specific targeted offenses, and these pressures may induce police to alter classification, recording, and reporting procedures. Such changes can have a dramatic impact on the amount and rate of crime. A classic example was the reorganization of the Chicago police department. As part of the reorganization, more efficient reporting and recording procedures were introduced, and reported crime increased dramatically from 57,000 offenses in one year to 130,000 in the next (Rae).

To make the problems with the UCR even more complicated, the reported statistics can vary across time and place as policies change, police technology becomes more sophisticated, laws and statutes are modified, commitment to the program wavers, demands for information change, available resources fluctuate, and so on (Hindelang). Unfortunately, even if all the difficulties of validity, reliability, and comparability were eliminated and the statistics became completely and uniformly accurate, there would remain the more serious problem of differential reporting to the police by victims and other citizens. There is evidence of substantial underreporting and nonreporting to the police by victims of crime; in fact, the majority of crimes committed are not reported to the police.

The assumption of the originators of the UCR that there is a constant ratio between crimes known to the police and crimes committed has been shown to be fallacious by studies using unofficial crime statistics. One may never know the actual volume of crimes committed, and therefore the true base remains indeterminate. But more importantly, underreporting or nonreporting to the police varies by offense type, victim and offender characteristics, perceptions of police efficiency, and the like. In short, the dark figure of undetected and unreported crime limits the adequacy of even the historically preferred crimes-known-to-the-police index of the amount and distribution of crime.

NIBRS. During the 1980s, law enforcement agencies sought to improve official reporting methods, particularly the UCR. In 1985 the Bureau of Justice Statistics (BJS) and the F.B.I. released Blueprint for the Future of the Uniform Crime Reporting Program (Reaves, p. 1). This blueprint outlined the next generation of official reporting methods, specifically the National Incidence-Based Reporting System (NIBRS). Starting with 1991 data, the UCR program began to move to this more comprehensive reporting system. While the UCR is essentially offender-based, focusing on summary accounts of case and offender characteristics, the NIBRS is incident-based, seeking to link more expansive data elements to the crime, included in six primary categories: administrative, offense, property, victim, offender, and arrestee (Reaves, p. 2).

The first segment, the administrative, is a linking segment that provides an identifier for each incident. Further, this segment provides the date and time of the original incident as well as any required special clearance for the case. The second segment, the offense, details the nature of the offense(s) reported. Unlike the UCR, which is limited to a relatively small number of F.B.I. index crimes, NIBRS provides details on forty-six offenses. This specificity allows for more accurate reporting of the offense, as well as improved ability to analyze other characteristics of the crime. The offense category also examines conditions surrounding the event, such as drug or alcohol involvement at the time of the incident, what type of weapon, if any, was used, and whether or not the crime was completed. Segment three deals with the property aspects of the incident, such as the nature of the property loss (i.e., burned, seized, stolen), the type of property involved (i.e., cash, car, jewelry), the value of the property, and if the property was recovered and when. The fourth segment, victim, lists the characteristics of the individual victimized in the incident. The victim's sex, age, race, ethnicity, and resident status are presented and, in cases where the victim is not an individual, additional codes for business, government, and religious organizations are provided. Each of the victims is linked to the offender, by the offender number and by the relationship between the victim and the offender. Segment five focuses on the individual attributes of the offender rather than the victim. The final segment, arrestee, gives information on those arrested for the incident—the date/time of the arrest, how the arrest was accomplished, whether or not the arrestee was armed, and age, gender, race, ethnicity, and residence status of the arrestee (Reaves).

Data collection for NIBRS follows a process similar to that of the UCR, with local agencies reporting to the state program, which passes the information along to the F.B.I. However, one major change exists for those states desiring to participate in the NIBRS program—to begin regular submission of NIBRS data a state must be certified by the F.B.I. (Roberts, p. 7). The state must meet the following four criteria before becoming certified: First, the state must have an error-reporting rate of no greater than 4 percent for three consecutive months. Second, the data must be statistically reasonable based on trends, volumes, and monthly fluctuations. Third, the state must show the ability to update and respond to changes within the system. And finally, the state NIBRS program must be systematically compatible with the national program.

Calls for service. Another method by which crime may be monitored utilizes emergency calls to the police. Some of the criticisms that have been leveled at arrest records (e.g., that they measure reactions to crimes rather than criminal involvement) and at victimization surveys (e.g., there may be systematic bias in the willingness of victims to report certain crimes to interviewers) may be addressed by this method of crime measurement.

It is suggested that the primary advantage of measuring crime through calls-for-service (CFS) is that it places the data closer to the actual incident. This removes additional layers in which bias or data loss can occur. For example, in order for a crime to be recorded as an arrest, the police must respond to the call, investigate the crime, find and arrest a suspect. At any one of these steps the process can be halted and nothing recorded, hiding the occurrence of the crime and contributing to the "dark figure." Similarly, within victimization surveys the respondent may forget events in the past, or the victim may choose not to give accurate information due to the sensitive nature of the crime. By placing the data gathering at the point of actually reporting the event to authorities means that the reports are "virtually unscreened and therefore not susceptible to police biases"(Warner and Pierce, p. 496).

As potentially valuable as these calls for service are, several weaknesses exist that create difficulty in utilizing them as crime measures. The first relates to the coding of a call to the police. Not all calls for police service focus on crime or legal issues—many are calls for medical or physical assistance, general emergencies, information requests, or "crank" calls. Clearly, they do not measure crime. At first glance, these appear easy to filter out of the data. But there are ambiguities; for example, how are medical conditions brought on by illegal activity (an individual consumes an illegal substance and has a negative reaction) coded? The call to 911 requests medical assistance but fails to mention the origin of the medical distress. The code for this event appears to be medical but in fact also represents a crime. Another concern surrounding the coding of a call has to do with the accuracy of what the individual is reporting to the operator. Not only can this lead to problems in the general categorization of a call as a crime (or not), but also in the specific crime being reported. The caller may not understand the nature of the event they are witness to, or the caller may desire a faster response from the police and inflate the severity of the offense. Further, even if citizens have a sound understanding of the legal nature of the event, they may be unable to articulate critical features of the event (e.g., high levels of anxiety, English as a second language).

A second major issue with CFS as a measure of crime is that many crimes come to the attention of the police by methods other than phone calls to the police department. Officers can observe crimes while patrolling or information can be directly presented to officers by citizens while on patrol or at station houses (Reiss). This creates a new aspect of the "dark figure"–reliance on CFS may tend to undercount crimes as police officers discover criminal activity through other means. Data collected by Klinger and Bridges found that officers sent out on calls encountered more crime than reflected in the initial coding of the calls (Klinger and Bridges, p. 719).

A final consideration in using CFS as a crime measure is that calls tend to vary according to the structural characteristics of the neighborhood. Where residents believe police respond slowly to their calls, where residents are more fearful of crime, and where there exists more criminal victimization, there will be systematic variation in the presentation of calls for service (Klinger and Bridges). For example, in high crime rate areas, residents may be sensitized to crime and report all behavior, resulting in many false positives. Thus, differences in CFS across communities may introduce additional sources of error.

Utilization of CFS data is an innovative approach to the measurement of crime. However, until the strengths and weaknesses of these records of initial calls to the police for a variety of services have been scrutinized to the same degree as the more traditional measures, some caution should be exercised with this "new" indicator of crime.

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