Abstract Forensic science continues to shape the world of justice, fueling crime investigations and signifying the progress of modern technology. While forensic science encompasses a multitude of techniques, the literature to follow will focus on the art of forensic autopsy. Though autopsies are more often used for purposes unrelated to crime, they play such a crucial role in murder investigations, that this field of forensic science has a large impact on where the investigation should begin. Forensic pathologists perform autopsies with the goal of revealing as many facts pertinent to the investigation of criminal cases. uch as how the victim died, when the death occurred, what caused the death, and the manner of the death in question. Detailed examination of the external body for various markings or physical features will provide clues as to how the victim died, when the death occurred, what caused the death, and the manner of death of the victim in question. The external examination can also reveal the identity of the victim through distinguishing birthmarks, ethnicity, sex, approximate age, hair color and length, as well as eye color dependant upon the cause of death and/or the state of decomposition amongst other various factors.
The internal examination of the body can further answer those questions that remain following the external examination. Through a number of different approaches, the internal examination consists of inspecting the internal organs of the body for evidence of trauma or other indications of the cause of death. The valuable techniques of forensic science and the abilities of the forensic pathologist in the investigative process are remarkable and often times are the starting point for investigators in criminal cases.
The literature that follows reveals those specific techniques and the purpose that they serve in forensic autopsies. The Forensic Autopsy: Processes of Crime Scene Investigation “To the living we owe respect, but to the dead we owe the truth”-Voltaire Forensic science continues to shape the world of justice, fueling crime investigations and signifying the progress of modern technology. While forensic science encompasses a multitude of techniques, the literature to follow will focus on the art of forensic autopsy. Though autopsies are more often used for purposes unrelated to crime, they play uch a crucial role in murder investigations, that this field of forensic science has a large impact on where the investigation should begin. Forensic pathologists perform autopsies with the goal of revealing as many facts pertinent to the investigation of criminal cases, such as how the victim died, when the death occurred, what caused the death, and the manner of death of the death in question. Detailed examination of the external body for various markings or physical features will provide clues as to how the victim died, when the death occurred, what caused the death, and the manner of death of the victim in question.
The external examination can also reveal the identity of the victim through distinguishing birthmarks, ethnicity, sex, approximate age, hair color and length, as well as eye color dependant upon the cause of death and/or the state of decomposition amongst other various factors. The internal examination of the body can further answer those questions that remain following the external examination. Through a number of different approaches, the internal examination consists of inspecting the internal organs of the body for evidence of trauma or other indications of the cause of death.
The valuable techniques of forensic science and the abilities of the forensic pathologist in the investigative process are remarkable and often times are the starting point for investigators in criminal cases. The literature that follows reveals those specific techniques and the purpose that they serve in forensic autopsies. Autopsy Defined The term “autopsy” was derived from the Greek word autopsia, meaning “to see for oneself”. More specifically, The Free Dictionary (2010) defines a forensic autopsy as, “A postmortem examination of a body performed with the intent of determining the cause and manner of a death in question”.
Autopsies are classified into two categories, clinical or medico-legal, commonly know as a forensic autopsy, which we will focus on. Forensic autopsy. Forensic autopsies are carried out by a forensic pathologist, or Medical Examiner, when there is a suspicion of criminal activity related to the death in question. The objectives of a forensic autopsy are to determine the exact cause and manner of death, establish the identity of the deceased, determine the time since death, collect trace evidence, and reconstruct the crime scene to aid law enforcement agencies in solving the crime (Charati, Jayachandar,Kotabagi, 2005).
To accomplish the above objectives, this “ultimate physical examination” includes a complete examination of medical history and the events leading up to death, collection and documentation of trace evidence on and around the body, photographing and cataloging of injuries. It also includes a detailed head to toe external examination, internal examination including organ and tissue dissection and microscopic examination, and laboratory and toxicology examinations of tissues and fluids.
Each autopsy is also accompanied by a written report detailing the pertinent findings, negative findings, and conclusions, including the cause and manner of death (Wagner, 2004). The forensic autopsy is part of an investigative process in which many steps are taken to come to the final conclusion. The Investigative Process Identification of the body. The circumstances immediately surrounding the body can be helpful in identification process. In the event that an ID is found on or near the body, identification can be determined at the crime scene. When ID is not found, identifying the body is accomplished using other methods.
In some cases it is possible for family to be called to identify the body when personal features or objects on the body of the deceased describe a missing person. When the above methods are not possibilities the examiner will resort to higher order methods of identification. Fingerprinting. “Recovering quality friction ridge impressions from human remains can be one of the most challenging tasks that an examiner can perform” (Uhle, 2010). The technical aspects of fingerprinting the living and dead might appear similar on the surface, but in most cases they are considerably different.
The fingerprints of recovered bodies are often compromised by environmental damage and decomposition thus making the fingerprinting process more challenging. Forensic examiners sometimes utilize a three-step process that is beneficial to fingerprinting. The process involves inspecting and cleansing the friction skin, reconditioning compromised friction ridge skin, and recording the post-mortem impressions. Examiners initially inspect the hands/fingers, to assess for and determine the cause of the damaged tissues, as this has an affect on the method of cleansing that is used.
Once the fingers are cleansed the examiner will attempt to recondition the skin through a variety of methods such as, stretching the skin or tissue building injections, which helps to remove wrinkles created by prolonged exposure to moisture and wetness, and boiling techniques that involve boiling the hand in water for a brief 5-10 seconds to allow for the water to visualize or elevate ridge detail. Only after they have successfully reconditioned the skin, are they able to make the fingerprint impressions. Dental identification.
The goal of the postmortem dental examination is “to locate, identify, and document anatomical structures, dental restorations, and dental appliances that will aid the comparison process” (Schrader & Tabor, 2010). Due to the durability of the human dentition, dental evidence comparison has become one of the most dependable and reliable methods of identification. The teeth have the ability to survive decomposition and withstand drastic temperature changes allowing them to have great durability and longevity, however the circumstances surrouding the death play a large role in the complexity of the dental identification.
As with most investigative techniques, dental identification is a step-wise process. Using photography, dental radiography, and dental charting, consistently accurate post mortem dental records can be created and subsequently compared to antemortem dental records. Photography. Photographs allow for later examination without the need to revisit the morgue. The photographs should be taken from various angles as well as macro photographs to allow for the details of various structures to be examined. Photographs are also helpful to aid in limited physical contact with fragile remains at risk of further degradation.
Dental radiography. Radiographs allow for the location of specimens that cannot be readily identified as human facial structure. The large-scale radiographs locate radiopaque structures, such as facial bones, that are present within the body bag or inside the body, i. e. swallowed teeth. When all dental material is located, further radiographs should be taken in an attempt to reconstruct the antemortem dental record (Schrader & Tabor). Dental charting. It is important to record the postmortem dental records in a manner that is beneficial in the comparison process.
It should be very detailed to include missing or damaged teeth and/or restored teeth. Pathologists will rely upon these records to correctly match up postmortem records with antemortem records in order to make an identification. Deoxyribonucleic Acid(DNA). A unique set of DNA is found within the nuclei of every human cell. Each cell also contains Mitochondrial DNA, which is an exception to the above. Mitochondrial DNA is passed on unchanged from the mother, therefore it is not unique to one individual. DNA molecules are broken down into short tandem repeats(STR) and duplicated many times.
They are then measured and produce a profile that is then compared with the standard sample. The results are reported as a match when all DNA sequences are identical, while keeping in mind the frequency that a DNA profile is found within a given population. As this is a costly and time consuming process coupled with the need for DNA samples from both parents or other family members, DNA analysis is only used whne all other efforts to identify the body have been exhausted (Wagner, 2009). External Examination The external exam can be broken up into three sections, preliminary exam, specific injuries, and specific body parts.
This is a systematic process that helps to ensure that there is not any evidence that is being passed by. Preliminary external examination. The preliminary exam begins with the simple practice of universal precautions, as the body is treated as potentially infectious from blood borne pathogens. This safety measure includes the use of mesh gloves, latex gloves, masks, gowns, shoe covers, and hats, all required garments per Occupational Safety Health Administration (OSHA). The examination then moves on to the body bag. Upon opening the bag, the body is immediately tagged along with the body bag.
Any clothing remaining on the victim is examined for trace evidence, such as fibers, tears, or bodily fluids, and any jewelry or valuables are collected and properly labeled. The body is thoroughly examined for trace evidence that may be present, i. e. hair, semen, or saliva. Any marks on the body are noted, natural or otherwise, and photographs are taken throughout the process to further document the findings. Any personal effects, such as jewelry, that are not logged as evidence must be returned to the family. Four signs of death.
The four signs of death are descriptions of biological reactions in the post mortem body. As the circulatory system is no longer pumping blood to the body, the body begins to go through biological processes. Known as Rigor Mortis, Livor Mortis, Algor Mortis, and Decomposition, these processes assist the Medical Examiner in identifying factors such as an approximate time of death and whether or not the body has been moved since death, which can indicate the possibility of a second crime scene. Rigor Mortis. Rigor mortis is the temporary stiffening of the post mortem body caused by interlocking proteins in the muscles.
The process begins within roughly 30 minutes to one hour after death and affects all muscles at the same time, however smaller muscles reach full rigor mortis quicker. Rigor mortis is noticed in nearly all muscles by about three hours post mortem. It can take up to 10 to 12 hours for full rigor mortis to develop at 70 degrees Fahrenheit, and it continues to last for abour 24 to 36 hours until decomposition begins to loosen the muscles (Wagner, 2004). Environmental influences can affect the rate of rigor mortis. Hot and humid conditions increase the rate of rigor mortis whereas cold temperatures slow down the process.
The above observations aid the Medical Examiner in estimating the time of death. The observation of rigor mortis can also be helpful in determining if a body has been moved from the location of death. If a body with rigor mortis is found on the ground in a sitting position it is clear that the body has been moved. Livor mortis. Livor mortis refers to the gravitational settling of the blood in the body following death. As the forced flow of blood by the heart ceases, it succombs to gravity. Blood seeps through the vascular channels due to the loss of vascular tone and settles in the surrounding tissues (Wagner, 2004).
As a general rule, livor mortis makes an appearance about 20 or 30 minutes after death and can be shifted or cleared for up to 10 to 12 hours post mortem. Fixed livor mortis can not be cleared with manual pressure. Two livor mortis patterns on a body indicat the probable movement of the body after death. The timeline of livor mortis assists examiners to determine an approximate time of death. Algor mortis. Though not commonly spoken of, algor mortis is the cooling of the body temperature following death. As the metabolism is lost, the body is gradually aloowed to assume the tempurature of its surrounding atmosphere.
It is generally accepted that at 70 degrees Fahrenheit the body cools at 1. 5 degrees per hour between about two to 15 hours after death. After roughly 12 hours the body is equal to the surrounding room temperature (Wagner, 2004). Many factors such as body mass, clothing, and air temperature affect the rate of cooling. The core temperature of the body will heat up if the external environment is warmer that room temperature. As conditions vary, it is difficult to accurately assess the time of death using algor mortis during the initial investigation of the body at the crime scene.
Decomposition. Decomposition occurs at the late stage of tissue breakdown. Enzymes are released by the dying cells thus causing an autolysis process in which the tissues are liquified. Gasses produced by the rapidly multiplying bodily bacteria aid in the further breakdown of the tissues (Wagner, 2004). Environmental factors very much affect the rate of decomposition. Again, cold temperatures slow the process and hot, humid climates expediate the decomposition. Forensic entomology. Insects found on the decomposing body provide clues as to the time of death.
Forensic entomologists study the insects as they relate to the death investigation. The entomologists collect and identify insect larvae from the corpse. The larvae are reared in incubators and the time of death can be estimated based on the “fixed” life cycle of the insect (Wagner, 2004). Identification of Specific Injuries. The external examination of the body also includes an evaluation of the specific injuries present on the body. The examiner will determine whether the wounds were inflicted by a blunt force or a sharp force weapon by examining the distinguishing characteristices of the wounds.
Blunt force wounds are tears of the skin. They are evident in lacerations, abrasions, contusions, and avulsions. Sharp force wounds are cuts in the skin. Stab wounds, incised wounds, defense wounds, puncture wounds, chopping wounds, and gunshot wounds all fall into the sharp force injury category. Examining Specific Body Parts. The Medical Examiner thoroughly examines the entire exterior of the body searching for identifying marks and characteristics and signs of injury or violence. The skin is the most carefully assessed organ on the exterior of the body.
The skin shows many various signs of physical injury or probable disease, such as carcinomas. The extremities are a focus in a forensic autopsy as these areas can be rich in trace evidence and clues to the cause and manner of death. Evidence from weapons can be carried on the hands, nails, and fingers. Hands and nails also show signs of natural disease processes. The examiner leaves no area uncovered. Internal Examinaton The examiner now begins to follow up on the evidence and clues discovered in the external exam.
The chest cavity is opened with a “Y” incision, and the skin is dissected back from the body to expose the underlying muscle and bone. Throughout the process the examiner is continually looking for signs and symptoms of injury. The skin dissection continues down to the abdominal cavity with the pathologist continually looking for hemorrhages, fluids, injuries, or signs of inflammation. The chest cavity is opened to reveal the organs and the pathologist surverys its contents looking for obvious signs of possible contributors to death.
When finished with the chest exam, the pathologist moves to examine the abdominal organs in the same manner. The pathologist will then collect samples of various bodily fluids such as blood, urine, bile and vitreous. Some substances remain in these fluids longer than they remain in the blood stream thus allowing for further drug testing when there is none detected in the blood. Organ and Tissue Removal and Individual Organ Exam. Once the pathologist has finished the initial dissection and survey of the internal body, the organs and tissues are removed for examination.
Each organ is weighed and measured and photographed throughout the process. The organs will undergo complete dissection and intense examination to uncover any hidden or obvious abnormailites beginning with the macroscopic appearance and continuing on to its microscopic appearance. The pathologist will make diagnoses and form opinions based upon these examinations which will be represented in the documentations. Examination of the Head, Skull, Brain, and Spinal Cord. Examination of the head, skull, and brain are required in a forensic autopsy regardless of whether the cause of death is obvious(Wagner, 2009).
Many clues can be hidden beneath the hair, such as weapons and injuries. This examination also allows the pathologist to examine these organs internally to locate injury not visible externally such as skull fractures that are frequently missed on radiographs. Many times what lies beneath provides the answers that lead to the detention or conviction of a suspect. Microscopic Examination and Postmortem Lab Analysis After the pathologist examines the body and collects various organ and tissue samples, they are examined microscopically. In forensic autopsies, the microscopic examination serves as a confirmation of the diagnosis lready made by the pathologist following the external and internal examinations. Fluids collected in the autopsy, vitreous, blood, etc, as well as tissues are sent to the toxicology lad for analyses. Finding evidence of drugs and other substances, not detected otherwise can play large roles in identifying a suspect and solving the crime. For example, it was noted that a suspect in a murder case was witnessed having a bottle of cleaner in his vehicle. It was discovered in a toxicology analysis that the victim had compounds of this cleaner in her system upon death. This evidence would likely lead to the conviction of the suspect.
Conclusion The forensic autopsy is a complex procedure with numerous components vital to drawing conclusions regarding the specifics of a death. The field of forensics is remarkable in its ability to tear down and then reconstruct a crime for the purpose of conviction. Not only are the findings vital to uncovering the details surrounding a suspicious death, they are necessary to allow the survivors to have a sense of closure in their time of grief. While the professionals work diligently to uncover the cause and manner of death, the family is struggling to uncover the answer to “why” the death occurred.
The advancements of forensic technologies, including autopsy, not only contribute to justice being served, but they continue to probe into the world of the unknown to uncover truth and peace of mind. “To be absolutely certain about something, one must know everything or nothing about it. ”-Voltaire References Charati, Lt Col SC. , & Jayachandar, Maj D. , & Kotabagi, Lt Col RB. , (2005). Clinical Autopsy vs Medicolegal Autopsy. Retrieved from http://medind. nic. in/maa/t05/i3/maat05i3p258. pdf Forensic Autopsy. (2010). The free dictionary. Retrieved from http://medical-dictionary. thefreedictionary. com/forensic+autopsy. Hess, Karen M. & Orthmann, Christine Hess. (2009 ). Criminal Investigation (9th Ed. ). Retrieved from CRCNetBase. Schrader, Bruce A. , & Tabor, Michael P. (2010). Forensic Dental Identification. In David R. Stern (Ed. ) Forensic dentistry (p. 163-186). Retrieved from CRCNetBase. Uhle, Aaron J. (2010). Fingerprinting and Human Identification. In David R. Stern (Ed. ) Forensic dentistry (Ch. 6). Retrieved from CRCNetBase. Wagner, Scott A. (2004). Color Atlas of the Autopsy (Ch. 1-11). Retrieved from CRCNetBase. Wagner, Scott A. (2009). Identification Methods. In Death scene investigation: A field guide (Ch. 11) . Retrieved from CRCNetBase