Timothy C. Hart

Reducing Housing Options for Convicted Sex Offenders: Investigating the Impact of Residency Restriction Laws Using GIS

Sex offender registries have been established throughout the United States. To date, 16 states have adopted additional residency restriction policies, precluding registered sex offenders from living within a certain distance of places where children gather. This study quantifies the impact of residency restrictions on housing options for registered sex offenders using Orange County, Florida, as a case study. A Geographic Information System (GIS) is employed to identify all occupied residential properties using parcel-level zoning data as well as those that fall within the 1,000-foot restricted buffer zones around attractions, bus stops, daycares, parks, and schools. Results indicate that housing options for registered sex offenders within urban residential areas are limited to only 5% of potentially available parcels and that bus stop restrictions impact the amount of livable area the most, followed by daycares, schools, parks, and attractions. The limited options to establish residency exist mostly in low-density rural areas. This supports the argument that residency restrictions for sexual offenders are a strong contributing factor to their social and economic isolation. The impacts of increasing the buffer to a proposed 2,500-foot zone are discussed, and a comparison of the individual restriction categories is presented.

Residential Proximity to Schools and Daycares An Empirical Analysis of Sex Offense Recidivism

Residential restrictions for sex offenders have become increasingly popular, despite the lack of empirical data suggesting that offenders’ proximity to schools or daycares contributes to recidivism. Using a matched sample of recidivists and nonrecidivists from Florida (n = 330) for the period from 2004 through 2006, the authors investigated whether sex offenders who lived closer to schools or daycares were more likely to reoffend sexually against children than those who lived farther away. No significant differences were found between the distances that recidivists and nonrecidivists lived from schools and daycares. There was no significant relationship between reoffending and proximity to schools or daycares. The results indicate that proximity to schools and daycares, with other risk factors being comparable, does not appear to contribute to sexual recidivism. These data do not support the widespread enactment of residential restrictions for sexual offenders.

Error propagation models to examine the effects of geocoding quality on spatial analysis of individual-level datasets

The quality of geocoding has received substantial attention in recent years. A synthesis of published studies shows that the positional errors of street geocoding are somewhat unique relative to those of other types of spatial data: (1) the magnitude of error varies strongly across urban-rural gradients; (2) the direction of error is not uniform, but strongly associated with the properties of local street segments; (3) the distribution of errors does not follow a normal distribution, but is highly skewed and characterized by a substantial number of very large error values; and (4) the magnitude of error is spatially autocorrelated and is related to properties of the reference data. This makes it difficult to employ analytic approaches or Monte Carlo simulations for error propagation modeling because these rely on generalized statistical characteristics. The current paper describes an alternative empirical approach to error propagation modeling for geocoded data and illustrates its implementation using three different case-studies of geocoded individual-level datasets. The first case-study consists of determining the land cover categories associated with geocoded addresses using a point-in-raster overlay. The second case-study consists of a local hotspot characterization using kernel density analysis of geocoded addresses. The third case-study consists of a spatial data aggregation using enumeration areas of varying spatial resolution. For each case-study a high quality reference scenario based on address points forms the basis for the analysis, which is then compared to the result of various street geocoding techniques. Results show that the unique nature of the positional error of street geocoding introduces substantial noise in the result of spatial analysis, including a substantial amount of bias for some analysis scenarios. This confirms findings from earlier studies, but expands these to a wider range of analytical techniques.

Reference data and geocoding quality: Examining completeness and positional accuracy of street geocoded crime incidents

Purpose – The purpose of this paper is to examine the influence of reference data, input address quality, and crime type on completeness and positional accuracy of street geocoded crime events.Design/methodology/approach – Existing data were analyzed using ArcGIS, including crime incident information, street network reference data, and address point and/or parcel reference data. Geocoding completeness was determined by the overall match rate. Positional accuracy was determined by comparing the Euclidian distance between street geocoded locations of crime events to the corresponding address point/parcel geocoded location.Findings – Results indicate that match rates vary by reference data, input address quality, and crime type. Local street centerline files consistently produced match rates that were as good as – and in many cases superior to – other types of reference data, including commercial data. Greater variability in positional accuracy was observed across reference data when crime type and input add...

Self-Defensive Gun Use by Crime Victims A Conjunctive Analysis of Its Situational Contexts

As a means for analyzing categorical data, conjunctive analysis is an emerging analytic approach used in both exploratory and confirmatory research. This technique is applied in the current study to examine two important issues related to the use of firearms as a means of self-defense by crime victims. Using data from the National Crime Victimization Survey, the current study uses conjunctive analysis (a) to examine the contextual factors associated with the use of a firearm by crime victims as a means of self-defense and (b) to identify the situational factors most closely associated with instances where the self-defensive use of a firearm is most and least effective. Results are discussed in terms of their implications for future research.

Situational Context of Student Bullying Victimization and Reporting Behavior: A Conjunctive Analysis of Case Configurations:

Bullying victimization is a growing problem for students, parents, teachers, and school administrators. Despite existing scholarship on various aspects of school bullying, certain facets of this important social issue remain underexplored. Using a pooled sample of 6th through 12th graders (N = 16,244), the current study analyzes the situational context of school bullying victimization. Findings from a conjunctive analysis of case configurations suggest that incidents of school bullying victimization are highly contextual, with few relevant factors demonstrating a constant “main effect” across situational profiles. Analyzing the situational context of bullying provides new insight into the dynamics of bullying, which are well documented in the literature. Results are discussed in terms of their contribution to the existing research and their implications for future study and policy.

Public Bus Stops and the Meso Environment: Understanding the Situational Context of Street Robberies

The concentration of crime in close proximity to bus stop locations has been the focus of increased scholarly attention. From an environmental criminology perspective, public bus stops are often viewed as crime generators because they represent specific areas within communities that are exceptionally busy (Brantingham and Brantingham, 1995). If public bus stops are located within particular parts of communities that lack adequate protection, they may be characterized as crime attractors (Brantingham and Brantingham, 1995). Regardless of whether bus stops are viewed as crime generators or attractors, past research suggests that criminal victimization, including violent victimization such as robbery, tends to cluster in close proximity to them (Levine and Wachs, 1985; Levine, Wachs and Shirazi, 1986; Loukaitou-Sideris, 1999; Newton, 2008).