Public Approval ofU.S. State Legislatures

The determinants of public approval for state legislatures have not received much attention, but one important finding is that more professionalized legislatures experience lower levels of public support. We argue that this result is an artifact of limited data and problematic model specifications. Analyzing a large national survey sample, we demonstrate that the negative relationship holds primarily for conservatives and to a lesser extent for moderates but not liberals. Additionally, we find that legislative approval in states with term limits and ballot initiatives is no different than in states without these institutions.     

IMMIGRATION AND CRIME IN AN ERA OF TRANSFORMATION: A LONGITUDINAL ANALYSIS OF HOMICIDES IN SAN DIEGO NEIGHBORHOODS, 1980–2000*

Emerging research associated with the “immigration revitalization” perspective suggests that immigration has been labeled inaccurately as a cause of crime in contemporary society. In fact, crime seems to be unexpectedly low in many communities that exhibit high levels of the following classic indicators of social disorganization: residential instability, ethnic heterogeneity, and immigration. But virtually all research conducted to date has been cross-sectional in nature and therefore unable to demonstrate how the relationship between immigration and crime might covary over time. This limitation is significant, especially because current versions of social disorganization theory posit a dynamic relationship between structural factors and crime that unfolds over time. The current study addresses this issue by exploring the effects of immigration on neighborhood-level homicide trends in the city of San Diego, California, using a combination of racially/ethnically disaggregated homicide victim data and community structural indicators collected for three decennial census periods. Consistent with the revitalization thesis, results show that the increased size of the foreign-born population reduces lethal violence over time. Specifically, we find that neighborhoods with a larger share of immigrants have fewer total, non-Latino White, and Latino homicide victims. More broadly, our findings suggest that social disorganization in heavily immigrant cities might be largely a function of economic deprivation rather than forms of “neighborhood” or “system” stability.     

Optimization of solid-phase microextraction (SPME) for the recovery of explosives from aqueous and post-explosion debris followed by gas and liquid chromatographic analysis

Solid-phase microextraction (SPME) has been evaluated for the recovery of explosives residues from aqueous samples and real post-explosion solid debris samples and optimized using gas chromatography with an electron capture detector (GC-ECD) and high-performance liquid chromatography with ultraviolet detection (HPLC-UV). A modified SPME/HPLC interface utilizing dual six-port valves allowed for independent optimization of SPME desorption and injection variables that provided improved chromatographic resolution and sensitivity. A unique combination of cyano and octadecyl columns resulted in the complete separation of the 14 explosives in EPA method 8330 mixture using HPLC with good quantitative results. At the optimum SPME conditions, the limits of detection (LOD) were found to be of 5 ng/mL to 16 ng/mL of explosives in water and 10 microg/kg to 40 microg/kg of explosives from soil. The technique has been successfully applied to the analysis of real post-explosion debris and can be adapted for use in the field utilizing portable chromatographic instruments.     

Elemental analysis of glass fragments by ICP-MS as evidence of association: analysis of a case

Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze glass evidence from a case in which a person broke a window in each of 15 vehicles in a parking lot in order to gain entry into the vehicles. The results of the analysis by traditional methods, which measure the properties of color, thickness, density, and refractive index, are also reported. A total of 15 known samples representing the windows on the cars and 42 questioned glass fragments recovered from the suspect and the police vehicle where the suspect was sitting were submitted for analysis. Density comparisons separated one of the known samples into three samples, increasing the number of known samples from 15 to 17. The concentrations of 16 elements were measured for all but three of the samples using an external calibration ICP-MS method with internal standardization. Color assessment (non-instrumental) separated the 17 known samples into two groups, and refractive index measurements resulted in six groups when the Emmons double variation method was used and ten groups when the Glass Refractive Index Measurement 2 (GRIM2) system was used. Elemental analysis, by itself, differentiated all of the known samples from each other and associated four of the known sample fragments with several of the questioned sample fragments. The informing power of RI, density, and elemental analysis comparisons is evaluated and a summary of the case results is reported.