ABSTRACT
This chapter discusses the typical progression of postmortem changes and a variety of methods, and their limitations, that may be considered by the field investigator to approximate postmortem interval (PMI) in animal carcasses. Estimating the PMI, also known as time since death, is important in many human and animal death investigations, as well as insurance and civil investigations, in order to establish a timeline of events. In addition, the investigator should strongly consider the close association between changes in muscle rigidity and body temperature over time. The deceased body undergoes predictable physical alterations including changes of color, muscle rigidity, free gas bloat, production of purge fluid and odorous gases, sloughing of the superficial layer of skin, destruction of soft tissues, and eventual destruction of bone. Body cavities and internal organs often become distended by decomposition gases produced by bacterial putrefaction. The most readily observable physical changes are body cooling, lividity, muscle rigidity, and decomposition.
