He is an urban sociologist whose research and teaching interests primarily focuses on issues related to minorities and the urban poor, with a particularly emphasis on race, crime, and the criminal justice system. He is a nationally recognized authority on racial profiling, which is the focus of his recently published book, Racial Profiling: Causes & Consequences (Kendall-Hunt, 2011). His research on racial profiling also appears in scholarly journal articles and college textbooks, and he has published research on police accountability and civilian oversight, health disparities, and the field of urban studies.