Editor’s Note: This article is part of an ongoing series about how different aspects of forensic science can help during death investigations. Learn about behavioral analysis, forensic entomology, livor mortis and rigor mortis.
In any death investigation, determining the approximate time of death is a crucial element for investigators. This is particularly true in cases of deaths resulting from a criminal act or murder.
Algor mortis refers to the change in the internal temperature of a human body after a person’s heart stops beating. Following death, the body no longer circulates blood or generates heat. Additionally, the metabolic processes of the muscles and organs cease.
As a result, the internal temperature of the deceased decreases in the hours following death until the body reaches the ambient temperature of the surrounding environment. The rate of decrease depends on several factors but, generally, following the first hour after death, the body begins to cool by one to one and a half degrees per hour.
Factors Affecting the Rate of Temperature Decrease
There are several factors to consider when one uses the internal temperature of a body to help estimate a person’s time of death. The ambient temperature of the environment in which a body is found may accelerate or decelerate the temperature loss process.
For instance, a body left in a very cold outside environment will decrease in temperature faster than one left in a hot, humid location. This change is due to the larger gap between the body’s temperature and the ambient temperature of the environment.
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The physical makeup of an individual also affects the rate of the deceased’s temperature loss. A body that is very muscular or obese will take longer to reach the surrounding ambient temperature. The insulating qualities of body muscle or fat as well as the additional skin surface area and the denseness of body tissues slow the temperature loss.
Age influences the drop in body temperature after death as well. Infants and elderly persons generally lose body temperature more quickly than full grown, middle-aged adults. This accelerated rate of temperature loss is typically a result of lower body fat levels and an overall smaller skin surface area.
If a person was battling an infection at the time of his or her death, that person’s internal body temperature may be several degrees higher than usual due to a fever. The feverish condition means that the body has to drop additional degrees before reaching the ambient temperature of the surrounding environment, which lengthens the algor mortis timeframe.
Thick clothing worn by a person at the time of death can act as an insulator to the body and extend the amount of time it takes for the internal temperature to drop. Conversely, if a body is nude or clad in minimal clothing, the loss in temperature will often be more rapid.
Algor Mortis Can Provide Critical Clues to Investigators
The use of algor mortis to assist in determining time of death provided crucial evidence in the case of Nava Baker, a three-year-old child who died as a result of abuse. When medical personnel first arrived at the death scene, they found Nava’s skin cold to the touch, indicating she had been dead for several hours. The mother’s boyfriend claimed he’d been performing CPR on the child just prior to the medics arriving.
However, the low body temperature of the girl helped to prove that his statement was false. Both the boyfriend and Nava’s mother were ultimately arrested for murder. Investigators later learned that the two adults had subjected the child to long-term abuse, which ultimately caused her death.
However, Nava’s mother and her boyfriend did not immediately report the toddler’s death to authorities. Prior to calling 911, they took several hours to clean up and alter the scene of the crime in an attempt to mislead police. During that time, Nava’s body temperature dropped several degrees, leaving a significant clue for law enforcement officials.
Algor mortis changes can be extremely helpful in determining the approximate time of a person’s death. Body temperature is one of the many potential clues utilized by crime scene investigators, forensic pathologists, and detectives during an investigation.
As in the Baker case, algor mortis may also verify or refute the statement of a witness or suspect. It is a valuable indicator that cannot be ignored by anyone checking the forensic evidence of a crime scene.
About the Author
Jennifer Bucholtz is a former U.S. Army Counterintelligence Agent and a decorated veteran of the Iraq and Afghanistan wars. She holds a Bachelor of Science in criminal justice, Master of Arts in criminal justice and Master of Science in forensic sciences. Bucholtz has an extensive background in U.S. military and Department of Defense counterintelligence operations. While on active duty, she served as the Special Agent in Charge for her unit in South Korea and Assistant Special Agent in Charge at stateside duty stations. Bucholtz has also worked for the Arizona Department of Corrections and Office of the Chief Medical Examiner in New York City. She is currently an adjunct faculty member at American Military University and teaches courses in criminal justice and forensic sciences. Additionally, she is an instructor for the Department of State’s Office of Anti-Terrorism Assistance and a licensed private investigator in Colorado. You can contact her at Jennifer.Bucholtz@mycampus.apus.edu.