Strength and Weakness of Statistical Measures of Crimes


The paper analyses strengths and weaknesses of statistical measures of crimes as those are applied in the US. To be more precise, the criminal data generation tools are further detailed and evaluated in different perspectives, such as Uniform Crime Reports (UCR) and National Incident-Based Reporting System (NIBRS) provided by the Federal Bureau of Investigations (FBI), the National Crime Victimisation Survey (NCVS) by the US Bureau of Justice Statistics. Also, the crime rates and specificities data are reported by means of unofficial self-reported studies, though those are out of the scope of this essay. Since none of these statistics-generating systems is perfect, the information collected by them altogether enables one to obtain more objective information on homicide rates and other crimes at large. At the same time, these systems have their shortcomings and strengths that have to be balanced with one another to make the criminal justice system operate on smoother basis and with higher efficiency.

FBI and the FBI Index Crime

The FBI is a legal organization in the USA, which has the mission "to protect and defend the United States against terrorist and foreign intelligence threats and to enforce the criminal laws of the United States". Overall, FBI deals with numerous crimes and violations, which can be observed in the FBI index, an expanded crime-reporting database, while homicide incidents are the cases of specific nature to be addressed. The information for these statistical resources is collected by means of UCR, NIBRS, and NCVS tools.

What Are the Strength and Weakness of FBI Index Crime Dealing with Homicides?

Whereas the FBI Index contains the data obtained from several crime data collection resources, as it has been previously noted, it is reasonable to assume that the information on homicide incidents can be presented from different angles.

How the UCR, NCVS, and NIBRS Work with and within FBI

All three crime data generating tools are direct elements of FBI Index. What is more, UCR is the initial database system of the agency, offering the generalised information on a variety of offences with expanded scope of nationwide coverage, while NIBRS is a comprehensive part of UCR itself that provides a more holistic and in-depth picture on crimes committed. Since the former wins in terms of reporting on the homicide cases frequency, the latter enables the investigators with more precise details relevant for and specified by localities or regions. Apart from that, NCVS originates from the US Bureau of Justice Statistics and presents victim's standpoint with respect to the crime investigated. Nonetheless, the information appropriate for homicide issues by this means is rather scarce. In any case, all these factors in relation to the three crime statistical measures are further considered.



As it has been stressed earlier, the UCR system incorporates the data reported by 17,000 policing agencies which is more than 95% of the general number of law enforcement departments. Therefore, the greatest advantage of this system is that it offers official statistics on serious crimes, involving different types of homicide, in the national domain, with an opportunity to specify it by regions.

At the same time, the fact that data provision for the system is not mandatory for the police agencies makes these data and an opportunity to consider the situation with homicide in the country incomplete. Indeed, the information on at least 5% of official reported murders and nonnegligent manslaughter remain not covered. What is more, the fact that this database collects only official data from reported and investigated offences demonstrates another drawback of the system. In particular, the so-called "dark figure of crime," i.e. the number of unreported and undiscovered homicide incidents, is not presented in UCR.

Despite that the UCR is the most experienced crime statistical instrument, it has developed a range of important shortcomings which prevent thorough data accuracy and quick response to investigating homicides among other crimes. Specifically, the problems linked to this measurement merit include:

  • prevalence of reporting severe crimes only on the grounds of hierarchy rule, which sounds as "for a single crime incident in which multiple offences were committed, only the most serious offence is reported". As a result, dealing with homicide, important details of those less severe offences being omitted in reporting may substantially impact the actual investigation procedure, making it hard to investigate objectively.
  • this nationwide database also fails to collect all relevant data on the cases considered, though those regarding murders are analysed more properly as compared to other crimes. To illustrate, rape cases are related to collecting data regarding women only;
  • the focus of data obtained is rather concentrated on "police behaviour" than the essence of "criminality" of the event.

It follows that deriving the data from this tool alone will not offer one to evaluate the actual situation with homicide rates throughout the state.


Again, whereas reporting on homicides and other crimes to NIBRS is not mandatory, only 36%, or 6,500 police departments report their data to this part of UCR programme. Regardless of that NIBRS comprises a subdivision of UCR, it has its distinct features as summarised in Table 1 below.

Differences between UCR and NIBRS

Table 1. Differences between UCR and NIBRS

In accordance with the reasoning provided by the FBI, the advantages that derive from using the NIBRS can be listed as follows:

  • due to that the system contains detailed information on a variety of crimes, i.e. 22 Group A offences, it will be possible for investigators to trace the connections between the homicide investigated and other types of crimes and criminals. Therefore, it will assist in narrowing the circle of suspects, to some extent;
  • the information within the NIBRS dimension is "detailed, accurate, and meaningful"; thus, it will be valuable for law enforcement agencies, policy-makers, sociologists, etc. in terms of investigation, researching, and even establishment of preventive measures in minimising a particular type of offence. For instance, this circumstance may involve differentiation of homicide attempts versus completed crimes 'and provides detalisation of recording all weapons (see Table 1);
  • in this respect, this system allows cooperation between different agencies in dealing with homicide incidents based on the comprehensive information it offers. Hence, the crime may be investigated and responded quicker;
  • also, "full participation in the NIBRS provides statistics to enable a law enforcement agency to provide a full accounting of the status of public safety within the jurisdiction to the police commissioner, police chief, sheriff, or director".

Nonetheless, there are weaknesses of this system are detected as well. Specifically, the comprehensiveness of the information collected is limited to the 36% of police departments which provide these data for recording. Consequently, no generalisations can be made with regard to the homicide crimes around the country. Simultaneously, ensuring the widening of the coverage scope for NIBRS as mandatory reporting system would become a win-win solution for quick responding to homicide in a nationwide domain.

Get to know how it works


The initial purpose of NCVS was linked to its capability to "complement the data provided by UCR" whereas the former considers the criminal events from the victim's perspective. This yearly nationwide survey involves interviewing of about 134,000 individuals from 77,000 households throughout the country. With regard to homicide crimes, the theorists and practitioners underline such benefit deriving from NCVS as better understanding of victim-to-criminal relationship and coverage of diversified populations in terms age, race, sex, habitat, etc. This factor can be helpful in investigation.

By the same token, NCVS has a few disadvantages. The first one is connected with a limited scope of the data collected as it comprises only seven types of offences. Second, the information obtained may be of doubtful reliability due to (a) inappropriately chosen targeted population for surveying; (b) "memory errors," "telescoping," and "errors in deception" of respondents.

How FBI Deals with Homicide Crimes Round the Nation, What They Attend to Do, Their Strength and Weakness

In order to be capable to address criminal offences in general and homicide cases in particular from multiple paradigms in the national arena, the FBI uses three above-analysed tools, i.e. UCR, NCVS and NIBRS. Whereas none of them provides a holistic picture on the homicide crimes alone, they altogether enable a more thorough understanding of the situation at large and in a specified location. What is more, operating the data from three official resources sets the question of their reliability, credibility and validity on a higher level as compared to unofficial statistics revealed by self-reported agencies. Besides, each of the systems obtains their information in a distinct manner. To illustrate, UCR and NIBRS get their data as self-reported from the policing agencies around the country. In contrast, NCVS collects the data by means of surveying the households' residents.

Apart from that, availability of such data provides the law enforcement agencies and appropriate authorities at place, as those who cooperate with the FBI, with an opportunity to plan and schedule their specific activities in terms of addressing homicide issues. These can involve "budget formulation, planning, resource allocation, assessment of police operations" to be capable to "address this crime problem at various levels". For instance, higher homicide rates in a specific location may require improved security measures or even refined state regulations to be implemented locally among other measures to be undertaken.

Also, the statistical data on specific types of homicide incidents enables the FBI to entice the specified policies or interventions to be put into in the regions where these cases prevail. This approach may and should be implemented in partnership with local officials and agencies. For example, the Table 2 below illustrates that there has been an increase in violent offences among police officers, or more precisely, the killing of a felon by a law enforcement officer in the line of duty, while the nationwide statistics on these instances shows the reverse situation. It follows that the FBI could have initiated paying more careful attention to arranging specific trainings to police staff in order to minimise such crimes occurrence.

expanded homicide data table

Table 2. Expanded homicide data: The killing of a felon by a law enforcement officer in the line of duty

However, there is one serious flaw in terms appropriate use of data and its manipulations by the FBI as it has been detected by public, especially credible media resources, such as The Wall Street Journal and Veterans Today, to list a few. In particular, a recent article in this media has shocked with a statement that, "The Saturday report by the Wall Street Journal suggests that more than 550 homicides by police officers between 2007 and 2012 were unaccounted for at the FBI's Uniform Crime Report". This fact may be considered from two perspectives. First, it has been proved earlier that the UCR collects the information from about 95% of the policing agencies. Thus, the unreported data may be linked to the 5% which did not reveal that statistics. Additionally, the reporters to the UCR themselves could have falsified or did not report about those incidents. Second, the issue allows assuming that the FBI could have manipulated the data by decreasing these indices on purpose, for the general improved picture, so to speak, as a monopolist in this informational domain.

In any case, this fact raises many questions and requires to be addressed. For instance, considering mandatory reporting to the FBI of all national police departments without exceptions and partnering with reliable unofficial self-reporters of crime incidents would allow improving the situation. With this option, the data collection techniques and resources would be more diversified and valid, excluding any potential monopolisation or manipulation of the data by the FBI as a single legal structure.


The paper presented a brief analysis of crime/ homicide data collection techniques available within the FBI structure, involving UCR, NIBRS, and NCVS, which allow considering this crime from different perspectives. As it has been revealed in the process of discussion of the topic, all these tools have their strengths and weaknesses, and certain ways to address these shortcomings have been highlighted. For example, expanding the coverage of the reported incidents to a nationwide level, more thorough analysis within each framework, partnering with unofficial self-reporting agencies can be named, to list a few.

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