He publishes widely in sociological theory (especially of religion and morality) and criminology. He is the author of three books, over a dozen peer-reviewed articles or handbook chapters and is currently series co-editor (with Jonathan Turner) of Evolutionary Analysis in the Social Sciences. Upcoming projects include a sociological theory of threat and group formation (When Groups Come Apart: Fission-Fusion Dynamics in Human Societies. New York, NY: Routledge) and continued work documenting how changes in routine activities are reducing the American crime rate.