Death Investigations

Death Investigations

CRJ336 Criminal Investigation

Colorado State University Global

Death can have many aspects in an investigation. There are five manners of death: Natural, Accident, Suicide, Homicide and Undetermined (Orthmann, Hess & Cho, 2017). Manner of death is the determination of how the injury or disease leads to death, which, in a death investigation, is conducted by a forensic pathologist (Valdes & Kiger, 2020). Forensic pathologists carefully examine all of the evidence tied to the death to help determine the cause of death.


Natural causes of death are what most of the population will experience. Some of those causes include fatal diseases, old age, strokes and heart attacks. In contrast to the other manners of death, natural deaths can be easily determined as the individual had been under the care of their primary physician (Orthmann, Hess & Cho, 2017). This is not always the case, though, as some homicides can be made to look like a natural death.

Accidental deaths are not always as they appear. Causes of accidental death include falling, unintentionally overdosing on medication, or a fatal automobile accident (Orthmann, Hess & Cho, 2017). Some accidental deaths can actually be the result of suicide or homicide, which is why it is important that these deaths are investigated primarily as homicides. A victim who appears to have fallen to their death could have actually been pushed or thrown, or they could have just accidentally fallen.

Suicide can be committed in a wide variety of ways. Defined as the intentional taking of one’s own life (Orthmann, Hess & Cho, 2017), suicide also needs to be investigated as a homicide until proven otherwise. Homicides can easily be made to look like suicides because of the many ways that suicide can be committed. Additionally, suicides can be made to look like accidental deaths, usually for insurance purposes (Orthmann, Hess & Cho, 2017).

Homicide and murder are often used synonomously, but there is a difference between the two terms. Homicide is the killing of one individual by another individual and are either classified as noncriminal or criminal (Orthmann, Hess & Cho, 2017). Murders are a form of homicide, but not all homicides are murders or criminal for that matter.


There are four levels, or stages, of mortis: Pallor Mortis, Algor Mortis, Rigor Mortis, and Livor Mortis (Jalan, Staughton & Daftardar, 2019). Once an individual has passed, chemical reactions in the body begin almost immediately. These stages of death occur in a timely and orderly manner and some stages can be instrumental to establishing time of death (Jalan, Staughton & Daftardar, 2019).

Pallor mortis is the very first occurrence after death. This stage of death happens within the first 30 minutes of death. Pallor mortis presents itself as paleness in the face and other parts of the body, usually the extremities (Jalan, Staughton & Daftardar, 2019). When it comes to determining time of death, pallor mortis is usually insignificant.

Algor mortis is the next stage in the process. Humans can control and maintain their internal temperature because we are warm blooded. When we die, obviously, we can no longer maintain that internal temperature and our bodies begin to cool. The rate at which temperature leaves the body can give some indication of time of death, but there are numerous factors that can affect algor mortis (Jalan, Staughton & Daftardar, 2019). Because there are so many factors that affect algor mortis, this stage of death alone cannot determine time of death.

Rigor mortis is the most well known stage of death. After death, a corpse will go limp, then it will completely stiffen (Jalan, Staughton & Daftardar, 2019). Rigor can be used as a tool in determining time of death as it sets in within two hours following death. The entire body will be fully rigid at the eight hour mark and rigor can last anywhere from 18 to 48 hours (Jalan, Staughton & Daftardar, 2019).

Livor mortis is the last level of death. Because the heart is no longer pumping blood through the body, the blood will begin to pool in the lowest part of the body (Jalan, Staughton & Daftardar, 2019). The lowest part of the body depends on the position of the body at the time of death. For example, if a corpse is lying prone, then blood will collect in the chest and abdomen. Livor mortis, also called lividity, gives the skin a bluish, purplish appearance (Jalan, Staughton & Daftardar, 2019).


Beyond the levels of death, there are many ways that time of death can be determined. The use of insects found in and around a corpse can be used to determine time of death. This can be done by determining the life stage that the insects are found in. Because insects have short lifespans and because it has been shown that different insects will appear at different levels of decomposition, time of death can be quite accurately determined (Sharma, Garg & Gaur, 2015). Forensic entomologists can use samples of insects found at the scene to run appropriate tests and determine time of death.

A recent study conducted at the City University of New York has found another way to more accurately provide time of death. Researchers have turned to analysing bacteria that live on and in our bodies to learn more about postmortem intervals. So far researchers have built statistical models that can predict time of death to within 55 days (Johnson, Trinidad, Guzman, Khan, Parziale, Debruyn, & Lents, 2016). The accuracy of these readings hold through extended periods of decomposition which is a significant improvement over current methods (Johnson, et. al., 2016).


Jalan, M., Staughton, J., & Daftardar, I. (2019, November 26). How Accurate Are TV Shows In Their Postmortem Analysis? Retrieved February 22, 2020, from

Johnson, H. R., Trinidad, D. D., Guzman, S., Khan, Z., Parziale, J. V., Debruyn, J. M., & Lents, N. H. (2016). A Machine Learning Approach for Using the Postmortem Skin Microbiome to Estimate the Postmortem Interval. Plos One, 11(12). doi: 10.1371/journal.pone.0167370

Orthmann, C. M. H., Hess Kären M., & Cho, H. L. (2017). Criminal investigation (11th ed.). Boston, MA: Cengage Learning

Sharma, R., Garg, R. K., & Gaur, J. R. (2015). Various methods for the estimation of the post mortem interval from Calliphoridae: A review. Egyptian Journal of Forensic Sciences, 5(1), 1–12. doi: 10.1016/j.ejfs.2013.04.002

Valdes, R., & Kiger, P. J. (2020, January 27). How Autopsies Work. Retrieved February 22, 2020, from