A lawyer is licensed and regulated at the State level, as well as by any federal court in which the attorney is admitted to practice. The first place to check is with the State Bar Association in the State(s) in which the lawyer is admitted to practice. Many states post disciplinary histories for review over the internet. If you do not find what you're looking for there, simply call the State Bar Association and ask them for the information. The nature of discipline can be either public or private, depending on the stage of the disciplinary proceeding and/or the nature of the discipline imposes. A disciplinary proceeding that results in a private reprimand, for example, could be less accessible than other discipline. Most State Bar Associations in the four States in which I am licensed also publish a list of their displinary actions in each month's Bar magazine or news publication. So if all else fails, find a library that includes the Bar magazines and search the monthly disciplinary reports published there.