The (Surprising) stability of youth crime rates

Despite the profound demographic and socioeconomic changes characterizing family life in recent years, youth crime rates have remained more or less constant since 1971. This finding is of interest given the intense public concern regarding the welfare of children. It also serves as a convenient basis for projecting the future volume of youth crime.     

The value of DNA material recovered from crime scenes

Abstract:  DNA material is now collected routinely from crime scenes for a wide range of offenses and its timely processing is acknowledged as a key element to its success in solving crime. An analysis of the processing of approximately 1500 samples of DNA material recovered from the property crime offenses of residential burglary, commercial burglary, and theft of motor vehicle in Northamptonshire, U.K. during 2006 identified saliva and cigarette ends as the main sources of DNA recovered (approximately 63% of samples) with blood, cellular DNA, and chewing gum accounting for the remainder. The conversion of these DNA samples into DNA profiles and then into matches with offender profiles held on the U.K. National DNA database is considered in terms of the ease with which Crime Scene Examiners can recover DNA rich samples of different sources, the location of the DNA at the crime scene, and its mobility. A logistical regression of the DNA material recovered has revealed a number of predictors, other than timeliness, that greatly influence its conversion into a DNA profile. The most significant predictor was found to be Crime Scene Examiner accreditation with offense type and DNA sample condition also being relevant. A similar logistical regression of DNA samples profiled that produced a match with an offender on the U.K. National DNA database showed no significance with any of the predictors considered.     

Age structure and crime rates: The conflicting evidence

Because arrest rates are especially high for teenagers and young adults, criminologists have long contended that age structure changes affect crime trends. In recent years, however, this belief has been drawn into question because crime has not declined even though high-crime age groups have shrunk. We argue that the age/crime relationship is probably exaggerated because the high arrest rates for younger persons are due partly to their lesser ability to escape arrest, younger persons commit more group crime, and the age structure of victims should be taken into account. We then review 90 studies that regress crime rates on age structure; only a small minority consistently finds significant relationships. Because of methodological problems in this research, one cannot conclude that the age/crime relationship does not exist, but the weight of evidence shows that forecasts based on demographic trends are not likely to be helpful.     

The effectiveness of forensic evidence in the investigation of volume crime scenes

This study investigates the effectiveness of forensic evidence in UK volume crime investigations. The main aim was to identify characteristics of forensic evidence that influence its effectiveness in converting detections into criminal charges, as well as to critically consider the effectiveness of a recent service level agreement (SLA) implemented by Wiltshire Police, which aimed at reducing CSI attendance. The sample consisted of 445 police recorded cases received from Wiltshire Police. Presence or absence and location-related characteristics of fingerprint, DNA, and footwear evidence were evaluated on the effectiveness of forensic evidence and examined within the contexts of different volume crimes. Results showed a high level of correlation in converting detections into criminal charges where the presence of DNA, footwear, and multiple evidence types was recorded; and a positive correlation between forensic evidence ineffectiveness and presence of fingerprints, particularly in residential burglaries. Differences between individual offence types were expressed. The most prominent feature influencing the effectiveness of forensic evidence was found to be related to the movability of the exhibit associated with the recovered evidence, with DNA recovered from non-movable items presenting the strongest effectiveness. Cases processed after the implementation of the SLA did not show significant differences in forensic evidence effectiveness as compared to cases processed prior to the SLA, however, they demonstrated a lack in effectiveness of DNA evidence. The findings of the current research provide a better understanding of the contextual influences on the potential of forensic evidence and can support improvement of crime scene screening and CSI resource deployment.     

Knowledge on DNA Success Rates to Optimize the DNA Analysis Process: From Crime Scene to Laboratory

DNA analysis has become an essential intelligence tool in the criminal justice system for the identification of possible offenders. However, it appears that about half of the processed DNA samples contains too little DNA for analysis. This study looks at DNA success rates within 28 different categories of trace exhibits and relates the DNA concentration to the characteristics of the DNA profile. Data from 2260 analyzed crime samples show that cigarettes, bloodstains, and headwear have relatively high success rates. Cartridge cases, crowbars, and tie‐wraps are on the other end of the spectrum. These objective data can assist forensics in their selection process.The DNA success probability shows a positive relation with the DNA concentration. This finding enables the laboratory to set an evidence‐based threshold value in the DNA analysis process. For instance, 958 DNA extracts had a concentration value of 6 pg/μL or less. Only 46 of the 958 low‐level extracts provided meaningful DNA profiling data.     

Self-reported crime rates of women prisoners

This paper presents findings from the first study of female prisoners' self-reports of criminal activity. Using the criminal career paradigm to frame the analysis, self-reported estimates of crime participation and frequency rates were examined for eight felony crimes. Important similarities between women and men were found in overall patterns of crime. Specifically, a small proportion ofboth women and men described committing a large portion of the total crimes reported. These data also suggest that women and men are similar in violent crime participation — a finding that varies from the current literature. Once active in a crime type, women and men committed assault, theft, and forgery at significantly different rates; no gender differences were found in the annualized frequency rates of burglary, robbery, motor vehicle theft, fraud, and drug dealing. However, although statistical differences were not found in the overall frequency of drug dealing, specific patterns of drug dealing reflected considerable gender variation, with a larger proportion of the female sample committing very frequent (daily) drug dealing activity. The findings reflect the value of the criminal career paradigm for the study of gender differences. Future research should include largescale quantitative designs that allow detailed analyses of correlates of the distinct criminal career dimensions.Points of view are those of the author and do not necessarily reflect the official position of the U.S. Department of Justice.This research was funded in part by the National Institute of Justice, Grant 87-IJ-CX-0048.     

A city-level analysis of property crime clearance rates

Theft, burglary, and vehicle theft are among the most frequently committed and least commonly cleared Part I offenses in the United States, but have received disproportionately little attention in the clearance literature. This study contributes to recent efforts to remedy this shortage by presenting offense-specific analyses of burglary, larceny, and vehicle theft clearance rates in a sample of 110 large US cities. Data were gathered from the Uniform Crime Report, the Law Enforcement Management and Administrative Statistics survey, and the American Community Survey. Independent variables comprised social disorganization measures (e.g. residential instability, poverty, etc.) and policing variables, including the use of broken windows policing. Although broken windows policing is related to higher clearance rates in a few prior studies, that effect was not observed in the present work. Racial diversity and police spending per capita (which were negatively associated with clearance rates) were the only variables that were significantly associated with the clearance of all three crimes.     

The effects of deprivation on the time spent examining crime scenes and the recovery of DNA and fingerprints

DNA and fingerprint identifications are now accepted as an integral part of the investigation of a wide range of criminal offences from burglary and auto crime to serious and major crime. Despite this, there is still much variation between U.K. police forces in the recovery of fingerprint and DNA material from crime scenes. Analysis of burglary and auto crime data for Northamptonshire, U.K., during a 3-year period has enabled an examination of the relationship between the deprivation of the neighborhood in which the crime was committed and the level of service provided by Crime Scene Examiners. The results indicate that the time spent examining a crime scene for forensic evidence is not affected by the deprivation of the neighborhood. Further, there is no statistical significance between deprivation and the recovery of fingerprints from the crime scene. The relationship between deprivation and DNA recovery is, however, statistically significant with DNA being recovered more frequently from less deprived neighborhoods.     

Measuring the impact of forensic science in detecting burglary and autocrime offences

As UK investment in forensic science has increased, the government has taken a fresh interest in how far this has led to dividends in terms of the detection of crime and its reduction. The Home Office funded 'Pathfinder Project' sought to monitor and document the complex relationships between the collection and use of forensic material (looking at a range of forensic science techniques) and its impact on crime detection. The project specifically targeted the 'volume' crimes of burglary and vehicle crime. Detailed data was gathered on all stages of the process between the collection and use of forensic material and crime detection. The model falls into two conceptual phases--scene attendance to suspect identification and identification to detection. From the analysis it was found that approximately one third of burglary and autocrime scenes are visited by SOCOs. While scientific identifications are only made in a minority of burglary and autocrime offences overall, it belies their importance. About one in ten of burglary and autocrime cases are cleared up by the police and it is estimated that fingerprints and SGMPlus were a contributory factor in achieving one third of these clear ups.     

Age-cohort analysis of arrest rates

Logistic regressions of age-period-cohort models for city arrest rates are estimated with data from seven U.S. cities for the years 1970–1980 to study the dependence of officially designated criminality in select offense categories on age. A sensitivity analysis is carried out to determine how dependent the findings are on details of model specification.     

Unregistered residents and registered crime: an estimate for asylum seekers and irregular migrants in Norway

The purpose of our study has been to better estimate the number and types of crimes committed by asylum seekers and irregular migrants. While data on immigration status for non-residents are lacking in Norwegian crime statistics, we use indirect identifiers (lack of a national ID number, citizenship, residency) to arrive at an estimate for persons with a pending asylum claim and the related group of irregular migrants (i.e. non-EU citizens). A very small amount of the total crimes registered with a known offender are committed by this group. However, these groups are most likely overrepresented as offenders compared to the registered resident population, also when taking age and gender into consideration. Our method is recommended in a field otherwise dominated by political arguments and as an alternative to registering asylum status in crime registers.     

Urban crime rates and the changing face of immigration: Evidence across four decades

Research has shown little support for the enduring proposition that increases in immigration are associated with increases in crime. Although classical criminological and neoclassical economic theories would predict immigration to increase crime, most empirical research shows quite the opposite. We investigate the immigration-crime relationship among metropolitan areas over a 40 year period from 1970 to 2010. Our goal is to describe the ongoing and changing association between immigration and a broad range of violent and property crimes. Our results indicate that immigration is consistently linked to decreases in violent (e.g., murder) and property (e.g., burglary) crime throughout the time period.     

Connecting the dots: Crime rates and criminal justice evaluation research

The National Research Council’s report on evaluating anticrime programs contains sensible suggestions for improving evaluation research in criminal justice but neglects the important role of substantive theory in linking evaluations of anticrime initiatives to variation in crime rates across time and place. A working knowledge of crime rates is essential for designing and evaluating anticrime programs. This essay calls for the development of a policy evaluation infrastructure that would support the continuous monitoring of crime rates, generate knowledge of crime-producing conditions, and link evaluation research findings to one another and to expected policy outcomes, notably crime reduction.

Beyond crime seriousness: Fitting the punishment to the crime

This paper presents an exposition of how the factorial survey approach may enhance empirical assessments of the complex judgment principles involved in public views of just punishments for convicted offenders. Ratings of the appropriateness of sentences given across 50 typical crimes obtained from a household sample (N=774) of the Boston SMSA and several special-interest samples in 1982 are examined in three alternative ordinary least-squares (OLS) regression equations. These analyses show there is not a one-to-one direct relationship between public perceptions of the seriousness of criminal acts and desired sanctions. Crime seriousness is modified by the characteristics of the offenders and victims and by the consequences of the crimes. Preferred punishments also vary in severity by demographic, experiential, and attitudinal characteristics of the persons who make the judgments.     

Value of DNA evidence in detecting crime

DNA material is now collected routinely from crime scenes for a wide range of offences and the timely processing of the DNA is seen as key to its success in investigating and detecting crime. An analysis of DNA material recovered from the volume crime offences of residential burglary, commercial burglary, and theft of motor vehicle in Northamptonshire, U.K., in 2004 has enabled the DNA to be categorized into seven sources. Further analysis using a logistical regression has revealed a number of predictors, other than timeliness, that greatly influence whether the DNA material recovered from a crime scene enables the crime to be detected. The results indicate that a number of these predictors are of statistical significance and may be just as relevant in determining whether DNA successfully detects the crime as the timeliness of the processing of the DNA material. The most significant predictor was found to be investigating officer accreditation with location, quantity, and type of DNA material at the crime scene also being relevant. Accreditation of the Crime Scene Examiner recovering the DNA material was found not to be significant. Consideration is given to where further emphasis is needed by the U.K. police service to maximize the opportunities to detect volume crime with DNA.     

Projecting crime rates: An age,period, and cohort model using ARIMA techniques

The object of this paper is to generate forecasts of U.S. index property and violent crimes. A three-step procedure is employed. First, the age-specific crime rates are decomposed into age, period, and cohort effects. Then the period and cohort effects are characterized using regression and transfer functions, respectively. Finally, these statistical models are used to generate forecasts of the period and cohort effects and hence forecasted values of the age-specific crime rates. The forecasts are compared with existing data and found to be quite accurate. Issues concerning the forecast efficiency of this approach compared to that of others are also discussed.     

Decision support for using mobile Rapid DNA analysis at the crime scene

Mobile Rapid DNA technology is close to being incorporated into crime scene investigations, with the potential to identify a perpetrator within hours. However, the use of these techniques entails the risk of losing the sample and potential evidence, because the device not only consumes the inserted sample, it is also is less sensitive than traditional technologies used in forensic laboratories. Scene of Crime Officers (SoCOs) therefore will face a ‘time/success rate trade-off’ issue when making a decision to apply this technology.In this study we designed and experimentally tested a Decision Support System (DSS) for the use of Rapid DNA technologies based on Rational Decision Theory (RDT). In a vignette study, where SoCOs had to decide on the use of a Rapid DNA analysis device, participating SoCOs were assigned to either the control group (making decisions under standard conditions), the Success Rate (SR) group (making decisions with additional information on DNA success rates of traces), or the DSS group (making decisions supported by introduction to RDT, including information on DNA success rates of traces).This study provides positive evidence that a systematic approach for decision-making on using Rapid DNA analysis assists SoCOs in the decision to use the rapid device. The results demonstrated that participants using a DSS made different and more transparent decisions on the use of Rapid DNA analysis when different case characteristics were explicitly considered. In the DSS group the decision to apply Rapid DNA analysis was influenced by the factors “time pressure” and “trace characteristics” like DNA success rates. In the SR group, the decisions depended solely on the trace characteristics and in the control group the decisions did not show any systematic differences on crime type or trace characteristic.Guiding complex decisions on the use of Rapid DNA analyses with a DSS could be an important step towards the use of these devices at the crime scene.     

Trends of indecent images of children and child sexual offences between 2005/2006 and 2012/2013 within the United Kingdom

Abstract

Little is known about the trends of indecent images of children (IIOC) offences, as UK criminal justice figures are unavailable within official crime data. This study aims to explore the rates of conviction and the relationship between IIOC offences and child sexual abuse offences from 2005/2006 to 2012/2013. The results indicated a continuing increase in offences of take, permit, distribute IIOC, rape of a child under 13, sexual activity of child under 16 and abuse of children through prostitution or pornography. Six out of a possible 17 correlations were significant, with the strongest correlation found between take, make, distribute IIOC and rape of a female under 13. Explanations for the findings are discussed and the utility of comprehensive prevalence figures for different stakeholders involved in addressing this crime issue.