This paper introduces the special Ulster issue of the Journal. It argues that Ulster offers enough similarities with other jurisdictions in the British Isles to enable comparison, and enough distinctive features to make such comparison interesting. The papers in the issue are briefly commented upon. This paper goes on to identify a number of topics not dealt with in this issue where comparative research may be fruitful. These include: conditional release from prison, trends in crime reporting and clear-up rates, the problems of maintaining civil rights at times of civil conflict, and the role of private security services in law enforcement.