When not conducted carefully, internal investigations can cause more harm than good. Deciding to investigate a suspected problem is only the first of several key determinations. The responsible executive must plan and execute the investigation deliberately to avoid self-inflicted harm. An organization can protect itself—while still conducting an investigation that is confidential, full and fair—only by carefully thinking about how best to uncover the alleged wrongdoing or compliance issues. Here are three rules for a company to keep in mind to minimize self-inflicted injury from an internal investigation.