In Chapter one I introduce the subject of geographic profiling, its use in criminology and its previous application to biology. I go on in Chapter two to examine the original model and develop a likelihood-based approach to fit the parameters to data from 53 UK invasive species. GP performs well on this novel problem, and outperforms other simple spatial modelling techniques. Using simulations I show that GP is particularly efficient at locating sources when there is more than a single source. Chapter three develops a Bayesian approach using Dirichlet Processes to account for the problem of multiple sources. This model was developed in collaboration with Robert Verity. This new Bayesian model outperforms the original model used in criminology and offers a range of additional information from the data. The Bayesian GP model is then used to determine the sources of malaria outbreaks in Cairo. These developments significantly improve and extend the theory and application of GP. In Chapter four I discuss the possible shapes of dispersal functions. I conduct a review of the literature and find a geometric mistake in the way linear distributions have been extracted from two-dimensional data. The correct back-transformation allows these dispersal distributions to be properly generated. Using this information; ecologists, conservationists and resources managers can now apply GP to real world problems and effectively allocate limited resources to locate sources of species invasions and disease outbreaks. I go on in Chapter five to develop a method for fitting the primary parameter sigma from the point pattern data and run simulations to show the effectiveness of this new approach. In Chapter six I illustrate the application of GP to three problems, one in criminology, one in ecology and one in epidemiology. I finish by summarising the work in this thesis and discussing the potential future developments and applications of GP.

Violence is considered a public health problem in the United States, yet little is known about the benefit of using a combined epidemiology and criminology (EpiCrim) approach to focus on urban youth gun violence. The purpose of this general qualitative study was to determine in what ways Akers and Lanier's EpiCrim approach in tandem with Benet's polarities of democracy approach is explanatory of gun homicides by youth in U.S. urban areas and if the Youth Risk Behavior Surveillance System adequately addresses gun abatement measures. Data were collected through semi structured interviews of 16 criminal justice practitioners and medical professionals with experience relative to juvenile justice policies pertaining to gun violence. Interview data were inductively coded, then subjected to a thematic analysis procedure. The findings indicate that EpiCrim provides a platform to focus research efforts on complex issues that are drivers for behavioral risk factors associated with youth gun violence in urban areas. Participants perceive a necessity for legislative revisions supporting gun violence research and the reduction of privacy issues that pose barriers to EpiCrim research. EpiCrim research can provide data that help identify the root cause of youth gun violence in urban areas, and the Youth Risk Behavior Surveillance System does not fully address gun abatement measures. The positive social change implications stemming from this study include recommendations to local, state, and federal legislatures to explore legislative action to incorporate EpiCrim strategies as a method to reduce gun violence among youth in urban communities.