Observing and measuring the changes that the human body undergoes following death, called postmortem interval changes, can help investigators estimate the time of death. The NIJ guide (p. 34) suggests recording postmortem observations and measurements for the following criteria:
· livor (color, location, blanchability, Tardieu spots , and whether or not the indications of livor are consistent with position of the body)
· rigor (stage/intensity, affected parts of the body, whether rigor has been broken, and any evidence that rigor is inconsistent with the scene)
· degree of decomposition ( putrefaction , adipocere, mummification , skeletonization, as appropriate)
· insect and animal activity
· scene temperature (be sure to document the method used and time it was measured)
· description of body temperature (warm, cold, frozen) or measurement of body temperature (again, document the method used and the time of measurement)
Determining the degree of livor, rigor, and decomposition, and estimating the body temperature are developed mostly through training and experience. The findings of the death investigator are documented through notes and pictures at the scene, and the medical examiner reviews and confirms these findings during the examination of the body.
Decedent identification is one of the most important aspects of the medicolegal investigation. It is imperative that the medicolegal investigator collect all items that are critical to personal identification. The NIJ guide (p. 33) suggests the following:
· direct visual or photographic identification of the decedent, if feasible
· scientific methods, such as fingerprints, dental records, and DNA comparisons
· circumstantial methods, such as personal effects, circumstances, physical characteristics, tattoos, and anthropologic data
The Forensic Autopsy Performance Standards (Peterson & Clark, 2006) promulgated by the NAME specifically address all aspects of the forensic autopsy, including the identification of the body.
Depending on the condition of the body, identification may be routine or complex. Determining the identity of highly decomposed, drowned, or burned bodies may require the use of multiple scientific and circumstantial methods, and some bodies remain unidentified. In 2004, medical examiner and coroner offices in the United States reported a total of 13,486 unidentified human decedents, mostly in large jurisdictions (those with a population greater than 250,000; Hickman et al, 2007). In routine cases, a family member or close friend may identify the decedent by viewing the body or photographs of the body.
Return to top of page
The medicolegal authority, whether a medical examiner or a coroner, has distinctive, legally defined responsibilities regarding death investigations. The main function of the medical-examiner or coroner system is the medicolegal autopsy. Additional responsibilities can include the following (NMRP, 1999, p. 39):
· ensuring the protection, identification, and transportation of the deceased
· identifying, locating, and notifying the next of kin
· establishing and noting the decedent’s vital statistics
· documenting related events that occurred near the time of the fatal incident
· obtaining relevant medical and antemortem records
· documenting medical, mental health, and social histories
· releasing the body to a funeral director
The medical examiner/coroner staff may also provide the family of the deceased with information regarding the autopsy, support services, and the release of the decedent.
A comprehensive medicolegal autopsy typically has three phases (Wagner, 2004). Premorgue analysis involves the death scene investigation and pertinent statements. Morgue analysis (the medicolegal autopsy) includes the examination of the body and any associated physical evidence collected from the body. Postmorgue analysis involves tissue sampling and toxicological, chemical, fingerprint, dental, and/or DNA analyses pertinent to the death investigation. As we have already discussed the premorgue processes—that is, the investigation of the death scene—the following sections will be devoted to morgue and postmorgue processing.