Violent victimization among immigrants: Using the National Violent Death Reporting System to examine foreign-born homicide victimization in the United States.

Limited research attention has focused on homicides involving foreign-born victims. Using data from the National Violent Death Reporting System, we examined 9428 homicides that occurred in 2017 in the United States across 32 states and D.C. Approximately 8% of homicide victims were foreign-born. Homicide victimization rates were substantially lower for foreign-born persons, compared to U.S.-born persons. However, foreign-born persons from Honduras, El Salvador, and Jamaica had a substantially higher risk of homicide victimization. Notably, few homicides involving foreign-born victims were gang- or drug-trade-related. With the growing number of immigrants in the United States, policy and prevention efforts should be guided by research.

Examining the impact of a crime gun intelligence center.

With gun crime on the rise, efforts to curb this form of violence have captured the attention of government agencies and police departments alike. One form of such efforts is the proliferation of Crime Gun Intelligence Centers (CGICs) in police departments across the country. However, with only three non-peer-reviewed evaluations of these CGICs to date, our understanding of their effectiveness is limited. The present study aims to fill this gap by examining the impact of the Phoenix Police Department's (PPD) CGIC on clearance rates and prosecutorial outcomes for gun crimes. The data for this study come from PPD's Records Management System (RMS), computer-aided dispatch (CAD) system, impounded evidence, National Integrated Ballistics Information Network (NIBIN) lead data, and arrest data. Prosecutorial data were supplied by the Maricopa County Attorney's Office (MCAO). This study examined pretest and posttest differences that occurred over the study period. Difference-in-difference (DID) models were calculated to assess the impact of the CGIC on the outcome measures of interest. We found that from the year prior to the CGIC to 2 years post-CGIC, NIBIN inputs increased by 115%, NIBIN leads increased by 163%, timeliness of entry (of ballistics evidence) improved with 32% of processed items entered within 24-48 h in the second year of the CGIC compared with only 3% the year preceding the CGIC, and clearance rates for arrests increased significantly. These findings have implications for the continued adoption of CGIC, as well as the utility of NIBIN.

Using Machine Learning Methods to Develop a Short Tree-Based Adaptive Classification Test: Case Study With a High-Dimensional Item Pool and Imbalanced Data.

This study explores advanced techniques in machine learning to develop a short tree-based adaptive classification test based on an existing lengthy instrument. A case study was carried out for an assessment of risk for juvenile delinquency. Two unique facts of this case are (a) the items in the original instrument measure a large number of distinctive constructs; (b) the target outcomes are of low prevalence, which renders imbalanced training data. Due to the high dimensionality of the items, traditional item response theory (IRT)-based adaptive testing approaches may not work well, whereas decision trees, which are developed in the machine learning discipline, present as a promising alternative solution for adaptive tests. A cross-validation study was carried out to compare eight tree-based adaptive test constructions with five benchmark methods using data from a sample of 3,975 subjects. The findings reveal that the best-performing tree-based adaptive tests yielded better classification accuracy than the benchmark method IRT scoring with optimal cutpoints, and yielded comparable or better classification accuracy than the best benchmark method, random forest with balanced sampling. The competitive classification accuracy of the tree-based adaptive tests also come with an over 30-fold reduction in the length of the instrument, only administering between 3 to 6 items to any individual. This study suggests that tree-based adaptive tests have an enormous potential when used to shorten instruments that measure a large variety of constructs.

Forensic Evidence and Criminal Investigations: The Impact of Ballistics Information on the Investigation of Violent Crime in Nine Cities.

We explore the impact of information from ballistics imaging hit reports on the investigation into violent crimes. Ballistics imaging hits link two crimes involving the same firearm by forensically matching tool marks on the fired bullets or cartridge cases. Interview data collected from detectives who received a hit report were used to explore the relationship between the presence of a hit report and outcomes in 65 gun-related violent crime investigations in nine U.S. police agencies. Findings indicate hit reports rarely contribute to identification, arrest, charging, or sentencing of suspects, because of delays in producing hit reports. On average, hit reports were completed 181.4 days after the focal crime. This delay forces investigations to proceed without the benefit of information from ballistics analysis. Additionally, hit reports rarely contained detailed information that was immediately useful to investigators. Instead, hit reports required additional research by the investigator to unlock useful information.

Gang truce for violence prevention, El Salvador.

OBJECTIVE: To estimate the effects on homicide rates of the gang truce that was brokered in El Salvador in 2012. METHODS: Mathematical models based on municipal-level census, crime and gang-intelligence data were used to estimate the effect of the truce on homicide rates. One model estimated the overall effect after accounting for the linear trend and seasonality in the homicide rate. In a moderated-effect model, we investigated the relationship between the truce effect and the numbers of MS13 (Mara Salvatrucha 13) and Eighteenth-Street gang members imprisoned per 100 000 population. We then ran each of these two models with additional control variables. We compared values before the truce - 1 January 2010 to 29 February 2012 - with those after the truce - 1 March 2012 to 31 December 2013. FINDINGS: The overall-effect models with and without additional control variables indicated a homicide rate after the truce that was significantly lower than the value before the truce, giving rate ratios of 0.55 (95% confidence interval, CI: 0.49-0.63) and 0.61 (95% CI: 0.54-0.69), respectively. For any given municipality, the effectiveness of the truce appeared to increase as the number of MS13 gang members imprisoned per 100 000 population increased. We did not observe the same significant relationship for imprisoned Eighteenth-Street gang members. CONCLUSION: In the 22 months following the establishment of a national gang truce, the homicide rate was about 40% lower than in the preceding 26 months. The truce's impact appeared particularly strong in municipalities with relatively high numbers of imprisoned MS13 gang members per 100 000 population.

Pseudohypoparathyroidism type Ia manifesting as intractable epilepsy in a 23-year-old female.

Pseudohypoparathyroidism is a rare disorder of calcium metabolism that involves target organ resistance to the action of the parathyroid hormone. As a result, calcium levels may become dangerously low, sometimes leading to seizures and other symptoms. We present a case of a 23-year-old Somalian female on antiepileptic therapy presenting with intractable epilepsy. She was subsequently found to have pseudohypoparathyroidism type Ia. She had multiple reasons accounting for loss of seizure control, including worsening hypocalcemia from resistance to the parathyroid hormone; vitamin D deficiency, which could have resulted from lack of exposure to direct sunlight and her antiepileptic medication; and extensive calcium deposition in the brain due to pseudohypoparathyroidism. The patient was stabilized with intravenous therapy and oral calcium, vitamin D, and calcitriol. Her antiepileptic therapy was changed to a medication that did not interfere with vitamin D metabolism or contribute to worsening hypocalcemia.

Firearm possession among arrestees in Trinidad and Tobago.

OBJECTIVES: To describe the sources that active offenders in Trinidad and Tobago use to obtain firearms and report their motivations for obtaining them. To estimate relationships between gang involvement, drug selling, and firearm ownership (or possession). SETTING: Port of Spain (Republic of Trinidad and Tobago). METHODS: A cross-sectional research design was used to collect self-report data from 421 recently booked arrestees (within 72 h of their arrest) in the Port of Spain Police District Detention Center. A survey instrument was used to collect data on firearm acquisition, drug use, gang membership and other behaviours. The sample provides insights about guns in the lives of arrestees in Trinidad and Tobago. RESULTS: 15% of respondents reported ever owning (or possessing) a firearm. Among the possessor group, 82% owned a gun primarily for defensive purposes, but approximately half reported using a gun in a crime. Nearly half of gun possessors stored their guns in outside locations. Firearm possession was greater among arrestees involved in gangs and those involved in drug selling. CONCLUSIONS: A comprehensive approach of prevention, intervention, and suppression strategies that are intended to prevent gun-related incidents should be focused on gangs, drugs, and guns. Searches for high-risk firearms should focus on public areas where gang members live and socialise. The study shows the value of collecting data from offender-based populations in the region for the purpose of directing violence-prevention strategies.

Risk and protective factors associated with gang-involved youth in Trinidad and Tobago.

OBJECTIVES: To examine the prevalence of gang involvement, the risk and protective factors associated with gang involvement, and the association between gang involvement and exposure to multiple risk and protective factors among school-aged youth in Trinidad and Tobago. METHODS: A survey instrument was administered to 2 206 students enrolled in 22 high-risk, urban public schools, from March-June 2006. It measured 30 risk factors and 13 protective factors within four domains: community, school, family, and peer-individual, plus levels of alcohol/drug use and delinquency. RESULTS: About 7.7% of youth reported being a gang associate; 6.8%, a former gang member; and 6.2%, a current gang member. Gang involvement was associated with perceived availability of handguns, residential mobility, having parents who favor antisocial behavior, early initiation of antisocial behavior, intention to use drugs, having antisocial peers, and having peers who use drugs. Those with social skills, belief in moral order, and interactions with prosocial peers were significantly less likely to self-report gang membership. Additionally, the probability of gang involvement increased as the number of risk factors increased. CONCLUSIONS: Gang membership among public school youth is about as prevalent in Trinidad and Tobago as it is in the United States, Canada, and Western Europe, but further research is needed. Although risk factors associated with gang involvement were present in all four domains, peer-individual risk factors were disproportionately likely to be associated with gang status. The most effective gang prevention strategies might be those that focus on multiple risk factors, with an emphasis on peer-individual factors and promoting a "belief in moral order."

Risk and protective factors associated with gang-involved youth in Trinidad and Tobago / Factores de riesgo y factores protectores asociados con la participación de los adolescentes en pandillas en Trinidad y Tabago

Objectives: To examine the prevalence of gang involvement, the risk and protective factors associated with gang involvement, and the association between gang involvement and exposure to multiple risk and protective factors among school-aged youth in Trinidad and Tobago. Methods: A survey instrument was administered to 2 206 students enrolled in 22 high-risk, urban public schools, from March-June 2006. It measured 30 risk factors and 13 protective factors within four domains: community, school, family, and peer-individual, plus levels of alcohol/drug use and delinquency. Results: About 7.7 percent of youth reported being a gang associate; 6.8 percent, a former gang member; and 6.2 percent, a current gang member. Gang involvement was associated with perceived availability of handguns, residential mobility, having parents who favor antisocial behavior, early initiation of antisocial behavior, intention to use drugs, having antisocial peers, and having peers who use drugs. Those with social skills, belief in moral order, and interactions with prosocial peers were significantly less likely to self-report gang membership. Additionally, the probability of gang involvement increased as the number of risk factors increased. Conclusions: Gang membership among public school youth is about as prevalent in Trinidad and Tobago as it is in the United States, Canada, and Western Europe, but further research is needed. Although risk factors associated with gang involvement were present in all four domains, peer-individual risk factors were disproportionately likely to be associated with gang status. The most effective gang prevention strategies might be those that focus on multiple risk factors, with an emphasis on peer-individual factors and promoting a "belief in moral order."

Objetivos: Examinar la prevalencia de la participación en pandillas, los factores de riesgo y los factores protectores asociados con la participación en pandillas, y la asociación entre la participación en pandillas y la exposición a diversos factores de riesgo y protectores en los adolescentes en edad escolar en Trinidad y Tabago. Métodos: Entre marzo y junio del 2006 se administró un instrumento de encuesta a 2 206 estudiantes matriculados en 22 escuelas públicas urbanas de alto riesgo. La encuesta medía 30 factores de riesgo y 13 factores protectores en cuatro ámbitos diferentes: la comunidad, la escuela, la familia y los compañeros individuales, además de los niveles de consumo de alcohol o drogas y la delincuencia. Resultados: Cerca de 7,7 por ciento de los adolescentes informaron que pertenecían a una pandilla, 6,8 por ciento, habían sido miembros de una pandilla y 6,2 por ciento lo eran en la actualidad. La participación en una pandilla se asociaba con la percepción de disponibilidad de pistolas, la movilidad residencial, tener padres que aprobaran la conducta antisocial, el inicio temprano de comportamientos antisociales, la intención de consumir drogas, tener compañeros antisociales y tener compañeros consumidores de drogas. Los adolescentes dotados de habilidades sociales, los que creían en un orden moral y los que se relacionaban con compañeros prosociales presentaban de forma significativa menos probabilidades de participación en una pandilla. Además, la probabilidad de participación en una pandilla se incrementaba si aumentaba el número de factores de riesgo. Conclusiones: La prevalencia de la participación en pandillas en los adolescentes de las escuelas públicas de Trinidad y Tabago es aproximadamente la misma que la observada en Estados Unidos, Canadá y Europa occidental, pero es necesario ampliar la investigación. Aunque los factores de riesgo asociados con la participación en pandillas estaban presentes en los cuatro...