Don Lindley is an assistant professor of criminology at Jesuit-run Regis University in Denver and was a member of the Denver Police Department for 33 years.

Byron R. Johnson is a professor of sociology at Baylor University in Waco, Texas, who has written widely on the relationship between religion and criminal behavior. He is the author of the entry “The Role of Religious Institutions in Responding to Crime and Delinquency” in The Oxford Handbook of the Sociology of Religion.

David Kratz Mathies is an assistant professor of philosophy and religion at Missouri Western State University in St. Joseph. He teaches an ethics course in which students examine and debate contemporary moral issues, including gun control.

Timothy Hall is an associate professor of philosophy at Oberlin College & Conservatory in Oberlin, Ohio. He teaches a variety of ethics courses, and his research interests include the applied ethics of gun control.

John K. Cochran is a professor of criminology at the University of South Florida in Tampa and has written widely on religion and crime.

The Rev. George Clifford is an Episcopal priest and ethicist serving at the Church of the Nativity in Raleigh, N.C. He has blogged about gun control.

James Kelly is associate professor of social work and director of the Grace Ann Geibel Institute for Justice and Social Responsibility at Carlow University, a small Catholic liberal arts school in Pittsburgh.

Michael Boylan is a philosophy professor at Marymount University in Arlington, Va., who has written about ethical perspectives on gun control.

Benjamin Wittes is a senior fellow in governance studies at the Brookings Institution and co-director of the Harvard Law School-Brookings Project on Law and Security.