David McDowall

Effects of Restrictive Licensing of Handguns on Homicide and Suicide in the District of Columbia

BACKGROUND Whether restricting access to handguns will reduce firearm-related homicides and suicides is currently a matter of intense debate. In 1976 the District of Columbia adopted a law that banned the purchase, sale, transfer, or possession of handguns by civilians. We evaluated the effect of implementing this law on the frequency of homicides and suicides. METHODS Homicides and suicides committed from 1968 through 1987 were classified according to place of occurrence (within the District of Columbia or in adjacent metropolitan areas where the law did not apply), cause (homicide or suicide), mechanism of death (firearms or other means), and time of occurrence (before or after the implementation of the law). The number of suicides and homicides was calculated for each month during the study period, and differences between the mean monthly totals before and after the law went into effect were estimated. RESULTS In Washington, D.C., the adoption of the gun-licensing law coincided with an abrupt decline in homicides by firearms (a reduction of 3.3 per month, or 25 percent) and suicides by firearms (reduction, 0.6 per month, or 23 percent). No similar reductions were observed in the number of homicides or suicides committed by other means, nor were there similar reductions in the adjacent metropolitan areas in Maryland and Virginia. There were also no increases in homicides or suicides by other methods, as would be expected if equally lethal means were substituted for handguns. CONCLUSIONS Restrictive licensing of handguns was associated with a prompt decline in homicides and suicides by firearms in the District of Columbia. No such decline was observed for homicides or suicides in which guns were not used, and no decline was seen in adjacent metropolitan areas where restrictive licensing did not apply. Our data suggest that restrictions on access to guns in the District of Columbia prevented an average of 47 deaths each year after the law was implemented.

A comparison of supplementary homicide reports and national vital statistics system homicide estimates for U.S. counties

This article examines agreement between homicide estimates from the Supplementary Homicide Report (SHR) and the National Vital Statistics System (NVSS) at the county level for 1980 to 1988. NVSS and SHR estimates exactly agree in 22% of the counties (68% if agreement is defined as no more than a difference of four homicides), but in some cases, they differ substantially. Although the NVSS generally exceeds the SHR, the pattern is not uniform: 28% of the counties report more SHR homicides than NVSS homicides. Differences between estimates from the two systems are related to population size. Large-population counties often have substantial differences in homicide counts, but the deflating effect of dividing by population yields small rate differences. In contrast, dividing by population magnifies differences in small-population counties and produces discrepancies in the rates that are not present in the counts. The NVSS and SHR differ somewhat in their definition of cases, and other disagreements result from ambiguities in or failures to follow data collection procedures within each system.

Criminalizing delinquency: The deterrent effects of the New York juvenile offender law

New Yorks Juvenile Offender (JO) Law of 1978 is a significant step away from separate systems of justice for adults and juveniles. The law requires that juveniles accused of violent offenses be tried in criminal court, and it provides penalties comparable to those for adults. This paper evaluates the impact of the JO Law on violent juvenile crime rates in New York City and in upstate New York. Analyzing arrest data through the use of an interrupted time series model, we conclude that the JO Law has not been effective in reducing juvenile crime. VioLit summary: OBJECTIVE: The objective of this research by Singer and McDowall was to evaluate the impact of the New York Juvenile Offender Law upon the rates of violent juvenile crime in New York City. METHODOLOGY: The authors employed a quasi-experimental interrupted time series analysis to evaluate the impact of the Juvenile Offender Law by comparing the levels of a time series - monthly juvenile arrests between January 1974 and December 1984 - both before and after an intervention - the introduction of the Juvenile Offender Law in September 1978. Arrest totals were provided by individual jurisdictions to the Federal Bureau of Investigations Uniform Crime Report, and data were collected for individuals between the ages of 13 and 15 for each of five crimes: homicide, rape, robbery, assault and arson. Analyses were conducted for New York City, for upstate New York and for Philadelphia for each of the five types of crime. Initial data manipulation involved controlling for within - series variation by developing a noise model to account for variations in seasonality, nonstationarity and autocorrelation. For each series, a number of different intervention models were included for consideration: an abrupt and permanent change model, one that involved abrupt but temporary change, and one that included use of a gradual and permanent change. The first model, using abrupt and permanent change, was adopted as the most appropriate for each series. The experimental group consisted of the 13 to 15 year olds in New York City, whilst control groups were formed from arrest data on 16 to 19 year olds in the City, 13 to 15 year olds in Philadelphia, and 13 to 15 year olds and 16 to 19 year olds in upstate New York. FINDINGS/DISCUSSION: The New York City Juvenile Offender Law provided for a shift away from the separate treatment of juveniles and adults, by allowing more punitive measures to be applied to serious young offenders, who would be tried in adult criminal court. The authors found that most of the experimental series were not affected by the intervention period. Homicide and assault arrests in New York City showed no change after the introduction of the Juvenile Offender Law, although arrests did decrease for both crimes in Philadelphia. For upstate New York, homicide rates showed no change, although assault arrest rates increased. Thus the introduction of the Law seemed to have no effect upon homicide or assault rates. Whilst rape and arson arrest rates decreased among 13 to 15 year olds in New York City, they also showed similar drops for 16 to 19 year olds, and they remained stable in upstate New York, with a decrease in arson in Philadelphia. Thus the decrease found among the young group in the City might just have been part of a general trend that was occurring amongst other groups in other areas as well, with no effect of the Law upon either rape or arson. Robbery arrests among 13 to 15 year olds in New York City and in upstate New York increased insignificantly after the Juvenile Offender Law had been introduced, although in two of the control series - the Philadelphia group and the 16 to 19 year olds in upstate New York - arrest rates for robbery significantly increased. Although the Law did not cause a decrease in robberies in the target group, it might have prevented an increase in arrest rates. However, differences between the groups were small, and the effectiveness of the Law in preventing an increase was seen by the authors as an implausible argument. The authors concluded that overall, their findings strongly supported the conclusion that the Juvenile Offender Law had no effect on rates of juvenile crime. They offer three explanations for the failure of the Law to reduce juvenile crime. Firstly, the Law might have been too weak to produce any significant effect upon crime rates, by not increasing the risk of punishment. However, the number of juveniles incarcerated since the Law came into effect had more than tripled, so this explanation seemed implausible to the authors - the risk of punishment had sufficiently increased. A second explanation offered by the authors was that the Juvenile Offender Law had no effect upon crime rates because youth were not responsive to the provisions of the Law, by not being deterred by the increase in severity and certainty of punishment. A last explanation was that the amount of time that had passed since the implementation of the Law was not enough to evaluate accurately its effectiveness in reducing crime rates. EVALUATION: The authors present a sophisticated and interesting analysis of the influence of the Juvenile Offender Law upon crime rates in New York City. The use of time series analysis, and the inclusion of a number of control groups, allowed for the comparison of results in the experimental area to other general trends that were occurring, and threats to internal validity, such as history and instrumentation, were controlled for as much as possible. The primary drawback with this research is its reliance upon official data as its source - such official records have been shown to substantially underestimate the true levels of crime that are taking place within the community, and are affected by arrest policies and practices, visibility of crimes, police funding, and many other uncontrolled factors. Actual numbers of arrests would have been an interesting additional piece of information, as would have separate analyses for males and females, anglos and non-whites, and individuals from different socio-economic status groups, in order to determine if there existed any differential effect of the Juvenile Offender Law upon these various groups. A more thorough discussion of the implications of these findings for future policy planning would also have been helpful. Even with some methodological drawbacks, the authors have still presented an excellent piece of well-written research which could help to inform policy and prevention planning in the years ahead. (CSPV Abstract - Copyright

Reciprocal Causal Relationships among Drug Use, Peers, and Beliefs: A Five-Wave Panel Model

Interactional theory posits a reciprocal relationship among drug use, association with drug using peers, and beliefs about drug use. Using five waves of data from a panel study of high-risk adolescents, two models are estimated to examine these assumptions. The results support the main hypotheses from interactional theory. Drug use and peer drug use are involved in a reciprocal causal relationship with the effect from drug use to peer drug use being slightly larger. Beliefs about drug use and drug use are also reciprocally related although the effect of beliefs on drug use is relatively weak. The effect of peer drug use on beliefs is stronger in later waves as compared to earlier waves, supporting interactional theorys assumptions about the importance of taking into account developmental stages of drug use. The importance of these findings for both theoretical development and intervention strategies is discussed.

Collective Security and the Demand for Legal Handguns.

One controversial element in the debate on firearms policy is whether crime and civil disorders contribute significantly to the private demand for firearms. In this paper we present a model to explain legal handgum demand that emphasizes the level of collective security as a key factor. Time-series data on legal gun demand in Detroit from 1951 to 1977 are consistent with a model in which individuals respond to three determinants of collective security: high violent crime rates, civil disordes, and police strength. The analysis suggests that low confidence in collective security contributes to both the need for and the resistance to gun control policies.

The incidence of defensive firearm use by US crime victims, 1987 through 1990.

It is well known that many crimes in the United States are committed with firearms. Less adequately documented is the frequency with which victims use guns in self-defense. We used National Crime Victimization Survey data to examine incidents where victims employed guns against offenders. Between 1987 and 1990 there were an estimated 258,460 incidents of firearm defense, an annual mean of 64,615. Victims used firearms in 0.18% of all crimes recorded by the survey and in 0.83% of violent offenses. Firearm self-defense is rare compared with gun crimes.

One With A Gun Gets You Two: Mandatory Sentencing and Firearms Violence in Detroit

Mandatory sentences for crimes committed with a gun are a popular policy because they promise a reduction in gun violence at a relatively low cost. In this article we present some results of a study of the implementa tion of such a law in Detroit, Michigan. Two major questions are discussed: (1) what effect did the Michigan gun law have on the certainty and severity of sentences; and (2) did the gun law reduce the number of serious violent crimes in Detroit? We find that, although the law required a two-year mandatory sentence for felonies committed with a gun and the prosecutor followed a strict policy of not reducing the gun law charge, there was little change in the certainty or severity of sentences that could be attributed to the effects of the gun law. Only in the case of assault was there a significant change in the expected sentence. Also serious violent crimes—murder, robbery, and assault—follow patterns over time that lead us to conclude that the gun law did not significantly alter the number or type of serious crimes in Detroit.

Prior Police Contact and Subsequent Victim Reporting: Results from the NCVS

This study investigated the association between victim reporting and the police response to past victimizations with data from the National Crime Victimization Survey from 1998–2000. The findings include: (1) investigatory effort by police when an individual had been victimized in the past increased the likelihood that the individual would report an ensuing victimization to the police; (2) however, this relationship only held when the victim, rather than someone else, reported the prior victimization to the police; (3) whether the police made an arrest after an individual was victimized in the past had no effect on whether the individual reported an ensuing victimization to the police; (4) the probability of victim reporting was unaffected by investigatory effort or whether an arrest was made after a prior victimization of a member of the victim’s household.

Underreporting of Justifiable Homicides Committed by Police Officers in the United States, 1976-1998

OBJECTIVES This study assessed the consistency of estimates of the number of justifiable homicides committed by US police officers and identified sources of underreporting. METHODS The number of justifiable homicides committed by police officers between 1976 and 1998 was estimated from supplementary homicide report (SHR) and National Vital Statistics System (NVSS) mortality data. RESULTS Nationally, the SHR estimate was 29% larger than the NVSS estimate. However, in most states this pattern was reversed, with more deaths reported in the NVSS. CONCLUSIONS Both systems underreport, but for different reasons. The NVSS misclassifies cases as homicides, rather than justifiable homicides committed by police officers, because certifiers fail to mention police involvement. The SHR misses cases because some jurisdictions fail to file reports or omit justifiable homicides committed by police officers.

The analysis of case-control studies in criminology

Case-control designs, in which subjects are selected conditionally on the value of a dependent variable, are well suited for research in criminology. For many research issues, case-control studies should be preferred over cohort studies because they can provide estimates of the same parameters, with equal standard errors, for less cost. This paper describes the case-control design and some of the problems that arise in interpreting them. An approach to analysis and interpretation that has developed in epidemiology is presented.