Focused Deterrence and the Prevention of Violent Gun Injuries: Practice, Theoretical Principles, and Scientific Evidence

Focused deterrence strategies are a relatively new addition to a growing portfolio of evidence-based violent gun injury prevention practices available to policy makers and practitioners. These strategies seek to change offender behavior by understanding the underlying violence-producing dynamics and conditions that sustain recurring violent gun injury problems and by implementing a blended strategy of law enforcement, community mobilization, and social service actions. Consistent with documented public health practice, the focused deterrence approach identifies underlying risk factors and causes of recurring violent gun injury problems, develops tailored responses to these underlying conditions, and measures the impact of implemented interventions. This article reviews the practice, theoretical principles, and evaluation evidence on focused deterrence strategies. Although more rigorous randomized studies are needed, the available empirical evidence suggests that these strategies generate noteworthy gun violence reduction impacts and should be part of a broader portfolio of violence prevention strategies available to policy makers and practitioners

Phenotypic correlates and consequences of dispersal in a metapopulation of house sparrows Passer domesticus.

1. We examine causes and consequences of natal dispersal within a metapopulation of house sparrows Passer domesticus in an archipelago in Northern Norway where a large proportion of the individuals is colour-ringed. 2. Less than 10% of the fledglings dispersed, i.e. left their natal island. 3. Dispersal was female biased and almost exclusively performed by juveniles. 4. The probability of natal dispersal was not related either to the body condition or the body mass of the juvenile. Similarly, neither clutch size nor hatching date explained a significant proportion of the variance in the probability of dispersal. 5. The probability of male natal dispersal was related to the rank of the fledgling in the size-hierarchy within the brood. Low ranking individuals that hatched early in the season were more likely to disperse. 6. In both sexes, the survival of dispersers at the island of establishment was higher than among the residents on that island. Similarly, dispersers survived better than adults that remained on their island of birth. 7. These results suggest that dispersal may be an adaptive strategy to avoid poor conditions in the natal area