Research Report Digest, Issue 7

August 2012

In NIJ's Research Report Digest, you will find brief descriptions of studies in various criminal justice disciplines, such as criminology and forensic sciences, and evaluations of technologies that are used in the law enforcement and corrections fields.

This issue includes reports based on NIJ-funded research that were added to the NCJRS Abstracts Database from Jan.-March 2012.

Find research reports related to:


A Preliminary Study of How Plea Bargaining Decisions by Prosecution and Defense Attorneys Are Affected by Eyewitness Factors 
Author: Kathy Pezdek

This preliminary study assessed how defense attorneys’ and prosecutors’ appraisals of the strength of eyewitness evidence in a case influenced their plea bargaining decisions. The findings suggest that prosecutors are likely to be open to plea-bargaining when eyewitness testimony is central to their case. This occurs regardless of the circumstances associated with the eyewitness identification (cross-race versus same-race identification or familiarity versus unfamiliarity of eyewitness with the perpetrator). However, prosecutors have enough confidence in eyewitness testimony, regardless of the aforementioned factors, to remain firm on their first plea bargain offer. The study involved a sample of 93 defense attorneys and 46 prosecutors from matched counties in California. The attorneys were presented with four scenarios involving eyewitnesses that varied in the following factors: the perpetrator’s race differed from the race of the eyewitness (cross-race), the race of the eyewitness was the same as that of the perpetrator, the eyewitness had prior contact with the perpetrator, and the eyewitness had no prior contact with the perpetrator. After reading each scenario, participants were asked five questions regarding their estimate of the probability that the defendant was guilty, the probability that they would win the case if it went to trial, whether they would plea bargain the case, and the lowest or highest plea bargain they would offer or accept. Defense attorneys perceived that the cross-race element of eyewitness evidence favored their client more than the same-race circumstance. Prosecutors were less likely to believe that cross-race identification would weaken their case compared with same-race identification evidence. When the perpetrator was familiar to the eyewitness, prosecutors indicated a higher probability of winning the case at trial. Defense attorneys were less confident of winning the case at trial if the perpetrator had previous contact or familiarity with the eyewitness.

Read the complete report A Preliminary Study of How Plea Bargaining Decisions by Prosecution and Defense Attorneys Are Affected by Eyewitness Factors (pdf, 46 pages)


Alternative Sentencing Policies for Drug Offenders: Evaluating the Effectiveness of Kansas Senate Bill 123, Final Report 
Authors: Don Stemen and Andres F. Rengifo

This report evaluates the effectiveness of Kansas’s legislation allowing alternative sentencing policies for drug offenders. It also assessed the effectiveness of Kansas Senate Bill 123. The bill passed in 2003. It created mandatory community-based supervision and drug treatment for nonviolent offenders convicted of a first or second offense of simple drug possession. The assessment examined the bill’s combined impact on diversion, recidivism rates and overall prison population rates.  It also assessed the impact on the work routines of the state’s criminal justice system professionals. The assessment examined the effectiveness of SB 123 over its first five years of implementation.  It found that offenders had lower incarceration and revocation filings at 12 months than those sentenced to standard supervision.  However, by 24 months the differences in recidivism measures had disappeared. It also found that SB 123 increased the long-term chances of incarceration and revocation filings compared to court services. SB 123 resulted in a slight decrease in drug possessors entering prison, thus reducing prison populations and reducing prison costs.  Successes included the increased availability of treatment programs for drug offenders, improved supervision and referral practices and improved revocation practices.  The law also produced better communication among criminal justice professionals at the state and local levels. 

Read the complete report Alternative Sentencing Policies for Drug Offenders: Evaluating the Effectiveness of Kansas Senate Bill 123, Final Report (pdf, 264 pages)

Classifying Adult Probationers by Forecasting Future Offending 
Authors: Geoffrey C. Barnes and Jordan M. Hyatt

This is a report on a demonstration project that developed a risk-prediction model for the Philadelphia Adult Probation and Parole Department (APPD).   The project’s risk-forecasting models increased the ability of APPD to predict recidivism, leading the agency to restructure its supervision protocols. The project led officials to set up three different prediction models based on a statistical process known as “random forest.” One benefit of random forest modeling is that there is no theoretical limit on the number of predictors that can be included in the model. The most recent version of APPD’s model produced an accurate forecast for 79,299 of the 119,935 probation case starts in the construction sample. These estimates suggest that this model can be correct nearly two-thirds of the time. The power and promise of the random forest forecasting methods is clear in Philadelphia. It has allowed the agency to stratify offenders by the risk they pose. Also, the agency can tailor supervision requirements and balance caseload sizes in the face of budgetary constraints.

Read the complete report Classifying Adult Probationers by Forecasting Future Offending (pdf, 64 pages)

Forensic Sciences

Application of Laser-Induced Breakdown Spectroscopy to Forensic Science: Analysis of Paint Samples 
Authors: Michael E. Sigman, Erin M. McIntee, and Candice Bridge

This project used laser-induced breakdown spectroscopy (LIBS) to characterize the elemental composition of automotive paint samples. The goal was to discriminate between two samples at a known level of statistical significance. The study determined that LIBS had a discrimination power of 90 percent (10 percent Type II errors) at a verified 5-percent Type I error rate. Discrimination was found to be slightly lower (86.6 percent) among the white color group. Study results suggest that LIBS may provide an important screening tool in the analysis of automotive paint samples. However, careful attention should be given to sampling protocols and the statistical comparison of samples. When two samples cannot be distinguished, a more accurate comparison should be used. Discrimination was tested across all paint samples, regardless of paint color or other features. A total of 200 paint samples were examined by the different analytical methods.

Read the complete report Application of Laser-Induced Breakdown Spectroscopy to Forensic Science: Analysis of Paint Samples (pdf, 84 pages)

Field Detection of Drugs and Explosives by SPME-IMS 
Authors: Jose Almirall, Patty Diaz-Guerra, Howard Holness, and Kenneth Furton 

This project sought to develop and validate portable instrumentation for the rapid detection and identification of controlled substances and explosives in a large volume, such as a room or a container. The researchers have successfully described the volatile and semivolatile chemical compounds of several illegal drugs and chemical explosives to help in the design and application of canine detection training aids. Researchers also developed preconcentration and sampling devices based on Solid Phase Microextraction for the capture of small quantities of the volatile compounds for subsequent detection using an Ion Mobility Spectrometer (IMS) with an interface that was developed in-house. The sampling and concentration of volatile signatures from a variety of drugs—including cocaine, cannabis, and MDMA (ecstasy), along with explosives and smokeless powders (propellants)—was achieved. The existing large installed base of 15,000 IMS instruments makes this technology viable as a crime-scene detection tool. The already proven use of detection canine teams also makes the approach a viable alternative to other instrumental detectors. It is also now possible to use miniaturized IMS instruments in the field or at the crime scene. The product from the completed research will advance the detection of drugs and explosives by both instrumental and canine methods of detection.

Read the complete report Field Detection of Drugs and Explosives by SPME-IMS (pdf, 275 pages)

Improve the NIBIN System by Providing Examiners a Capability to Match Infrared Images of Firing Pin Impressions and Deformed Bullets as Well as Accurate Large Database Searches 
Author: Francine Prokoski

This project focused on ways to improve the National Integrated Ballistic Information Network (NIBIN) by providing examiners with advanced capabilities. Three improvements are recommended. First, NIBIN should be able to identify cartridge casings by using infrared (IR) images of firing pin impressions (FPI). Second, NIBIN should be able to identify bullets by using IR images of land impressions. Third, NIBIN should be able to perform an accurate high-speed search of a large database to identify fired cartridge casings. The project was divided into three separate but inter-related efforts. First, it determined the persistence of FPI by collecting 1,000 cartridge cases fired in each of eight different firearms. Second, it conducted a proof-of-principle test using IR to get accurate matches of fired bullets bearing minimal damage collected from sample firearms. Third, it created a large database of cartridge cases that contains multiple fired cartridge cases from an unknown number of firearms. The ability to image, store, and accurately identify sibling cartridge cases from a large database of infrared images was clearly demonstrated.

Read the complete report Improve the NIBIN System by Providing Examiners a Capability to Match Infrared Images of Firing Pin Impressions and Deformed Bullets as Well as Accurate Large Database Searches (pdf, 77 pages)

Recovery and Interpretation of Burned Human Remains 
Authors: Steven A. Symes, Dennis C. Dirkmaat, Stephen Ousley, Erin Chapman, and Luis Cabo 

This study addressed the multiple forensic issues associated with the recovery and interpretation of burned human remains. It linked rigorous scene recovery and documentation methods with laboratory analyses of heat-altered human remains from fatal fire scenes. The protocols developed from this research showed that a fatal fire scene could be completely excavated in a few days. This can be done with comprehensive documentation, high evidence detection and recovery rates, and minimal evidence change. The research results show that a complex fire scene can be processed and documented in 2-3 days. The evidence recovery exercises showed that evidence could still be detected, identified and analyzed after aggressive fire-suppression efforts. Further, the study showed that regular, clear, normal patterns of heat alteration of the human body can be identified and successfully used to detect suspicious cases.

Read the complete report Recovery and Interpretation of Burned Human Remains (pdf, 236 pages)

Law Enforcement

The Impact of Shift Length in Policing on Performance, Health, Quality of Life, Sleep, Fatigue, and Extra-Duty Employment 
Authors: Karen L. Amendola, David Weisburd, Edwin E. Hamilton, Greg Jones, Meghan Slipka, Anneke Heitmann, Jon Shane, Christopher Ortiz, and Eliab Tarkghen

This report presents data on the prevalence of a compressed workweek for law enforcement officers, which extends the hours for a shift and reduces the number of workdays per week. It is the first known comprehensive randomized experiment to determine the effects of shift length on officers’ work performance, safety, health, quality of life, sleep, fatigue, off-duty employment and overtime use. The research involved law enforcement agencies in Detroit, Mich., and Arlington, Texas. The findings showed no significant differences between three shift lengths regarding work performance, health, safety and family conflict. However, officers working 10-hour shifts averaged significantly longer sleep periods and reported a better quality of work life than did the officers working 8-hour shifts. Officers working 12-hour shifts experienced more sleepiness (subjective measure of fatigue) and lower levels of alertness at work than those assigned to 8-hour shifts. Officers who worked 10-hour shifts spent less time in off-duty employment and worked less overtime. This can result in cost savings and potentially more family and leisure time for officers working on a 10-hour shift. A 10-hour shift may be a viable alternative to the traditional 8-hour shift in larger agencies; however, caution is advised in adopting 12-hour shifts. Reduced levels of overtime use for officers working 10-hour and 12-hour shifts suggest that agencies will save costs by adopting compressed work weeks. Work performance was measured using both laboratory simulations and departmental data. Health, quality of life, sleep, sleepiness, off-duty employment and overtime hours were measured by self-reports, including surveys, sleep diaries and alertness logs.

Read the complete report The Impact of Shift Length in Policing on Performance, Health, Quality of Life, Sleep, Fatigue, and Extra-Duty Employment (pdf, 201 pages)

Shifts, Extended Work Hours, and Fatigue: An Assessment of Health and Personal Risks for Police Officers 
Author: John M. Violanti

This study examined police officers’ involvement in shift work and its impact on adverse health and psychological results. The study found that officers working midnight shifts were, on average, younger. They had a slightly higher mean number of metabolic syndrome components (a cardiovascular risk syndrome). The findings suggest that shorter sleep duration and more overtime, combined with midnight shift work, may be important contributors to the metabolic syndrome. Night shift work was significantly and independently associated with snoring and associated apnea, which are linked to poor sleep quality. Officers on the night shift who had sleep problems were at higher risk for obesity. Among officers with higher posttraumatic stress disorder (PTSD) symptoms, the prevalence ratio of suicide ideation increased by 13 percent with every 10-unit increase in the percentage of hours worked on afternoon shift. The prevalence of suicide ideation significantly increased among policewomen with higher depressive symptoms and increasing day shift hours, as well as among policemen with higher PTSD symptoms with increasing afternoon shift hours. From a preliminary analysis, nearly twice as many day-shift workers (6.6 percent) died during the follow-up period compared with either afternoon (3.3 percent) or night-shift workers (3.4 percent). However, because day-shift workers were 9-10 years older on average than afternoon or night shift workers, possibly older age was responsible for their increased mortality. There were increased risks for cancer and cardiovascular disease across all shifts compared to the general population.   

Read the complete report Shifts, Extended Work Hours, and Fatigue: An Assessment of Health and Personal Risks for Police Officers (pdf, 64 pages)


The Power of Developmental Assets in Building Behavioral Adjustment Among Youth Exposed to Community Violence: A Multidisciplinary Longitudinal Study of Resilience 
Authors: Sonia Jain and Alison K. Cohen

This research study examined the behavioral functioning of youth exposed to community violence. It focused on how developmental assets may promote resilience into adulthood among urban youth exposed to community violence. Researchers and practitioners have repeatedly noted great variation in the behavioral functioning of youth exposed to community violence. Several studies across various fields have documented the harmful effects of exposure to violence, while other studies have considered how developmental assets promote positive youth development. Yet, few studies focus on resilient youth. And few studies have examined how developmental assets may shape resilient trajectories into adulthood for youth exposed to violence. The authors examined multilevel longitudinal data from 1,114 youth ages 11-16 from the Project on Human Development in Chicago Neighborhoods. The researchers considered whether baseline family, peer and neighborhood-level protective factors predicted behavioral adjustment 3-7 years later among youth. Behavioral adjustment varied across waves and by exposure to violence. In the short term, being a victim was associated with increased aggression and delinquency. In the long term, though, both victims and witnesses to violence had higher chances of behavioral adjustment. Family, friend and neighborhood support, family boundaries and collective efficacy had protective effects. Also, family support, positive peers and meaningful opportunities changed the effect of exposure to violence, increasing the chances of behavioral adjustment. Programs that help nurture these specific supports and opportunities can promote positive behavioral trajectories and resilience.

Read the complete report The Power of Developmental Assets in Building Behavioral Adjustment Among Youth Exposed to Community Violence: A Multidisciplinary Longitudinal Study of Resilience (pdf, 72 pages)

Date Created: August 27, 2012