David McDowall is editor of the Journal of Quantitative Criminology. He also is co-director of the Violence Research Group, a collaborative research effort that studies patterns of interpersonal violence.Professor McDowall is especially interested in time series analysis of patterns in crime and violence. His recent research includes an evaluation of the preventive effects of juvenile curfew laws on youth crime, studies of defensive firearm use, and an examination of disagreements between homicide data sources.