When researching issues of legal ethics, court opinions can be found in the traditional case law databases in Lexis and Westlaw.
However, you will also need to consult sources beyond the familiar cases and statutes, such as codes of professional ethics (model codes and state codes) and ethics opinions issued by state and national bar associations.
To assist you with your research, there are numerous secondary sources that focus specifically on issues in legal ethics. These secondary sources, including books and journal articles, are designed to help you understand the issues and locate primary materials.