The sudden or unexplained death of an individual has a profound impact on families and friends of the deceased and places significant responsibility on the agencies tasked with determining the cause of death. Increasingly, science and technology play a key role in death investigations. One of the hallmarks of science is adherence to clear and well-grounded protocols. In many jurisdictions, responsibility for conducting death investigations may rest with pathologists, medical examiners, or coroners, in addition to their other duties. There is little training available in the best procedures for handling these crucial and sensitive tasks. To help fill the gap, the National Institute of Justice, joined by the Centers for Disease Control and Prevention and the Bureau of Justice Assistance, supported the development of the guidelines presented in this report. These guidelines were produced with the vigorous participation of highly experienced officials and professionals who served on the National Medicolegal Review Panel. A technical working group of 144 professionals from across the country provided the grassroots input to the panel's work. Jurisdictions will want to carefully consider these guidelines and their applicability to local agencies and circumstances. By adhering to agreed-upon national standards, death investigators can arrive at the truth about a suspicious death. Families and friends can be consoled by knowing what happened to their loved one, and justice can be administered on the foundation of truth that must always guide our work.