Cause of Death
To understand suspicious death the crime scene investigator should understand the various causes of death and the manner of death. The cause of death refers to the disease or injury responsible for initiating the chain of events that results in death. Some examples of causes of death include cancer, heart disease, pulmonary embolism, gunshot wound(s), stabbing wound(s) and asphyxiation by strangulation or hanging. They may be acute or chronic. The cause of death should reflect the first event that sets into motion a number of sequential events, such as broken bones from a blunt injury leading to immobilization resulting in pulmonary embolism. In this case the blunt trauma is the original cause, whereas the pulmonary embolism is the final cause of death. One would expect the cause of death to read ‘Cause of death = Pulmonary embolism due to blunt trauma injury to the skeletal system [here nominate the bones broken]‘.
Manner of Death
The manner of death relates to the circumstances in which the death occurred, and is generally divided into five categories:
• Natural Death is due to a natural process or disease.
• Accident Death is due to the unintentional or inadvertent actions of the deceased or another person.
• Suicide Death is due to an intentional act or acts of the deceased who anticipates his or her resultant death.
• Homicide Death is due to the direct action of another.
• Undetermined or unknown The circumstances surrounding the death cannot be determined with reasonable certainty.
It is important for the crime scene investigator to be knowledgeable about death scenes. It is also important for a forensic pathologist to attend the scene, however this is not always possible, particularly in rural or remote communities. A heavy burden is therefore placed on the crime scene investigator who must have the knowledge and skills to understand fully the various causes and manner of death. This can only be achieved by visiting as many death scenes as possible. Scenes provide important information that may indicate cause of and means of death. The environment at the scene may help explain the condition of the body when it was discovered. If the deceased died while lying close to a heater, the body will decompose faster than usual. If the deceased collapsed on to an irregular or rough surface, this may explain minor injuries that are found on the body. Postmortem injuries should not be confused with antemortem injuries. Cause of death may be obvious – for example, a gunshot wound to the head – however, to determine the manner of death, further information will be required, such as whether this was an accident, a suicide or a homicide.
Death scenes should be treated as homicide scenes and dealt with as such until the contrary is proved. This can only be achieved through detailed examination and examination.
There are now two distinct tasks ahead of the crime scene investigator. The first is the technical recording and retrieval of potential evidence from the scene. Just as important is the second, the reconstruction in the mind of the crime scene investigator of the events surrounding the death. This article will discuss the technical issues first, and the reconstruction issues second.
Scene of Death
When a violent or suspicious death is discovered, the death scene should be secured immediately so that no one will have an opportunity to change it in any way. Indoor scenes may be easy to secure and protect. Outdoor scenes can be difficult. The more urban the scene, the more difficult it is to secure, as there will be a need for several scene guards and the setting up of cordons. The more remote the scene, the easier it is to secure. The weather and movement of predatory animals through common approach paths, and the maintenance of a scene log to record visits to the scene, add a dimension to the processing of a crime scene and the condition in which the deceased may be found. Outdoor scenes may be cooler than indoor scenes and the weather can have an impact as can the movement through a scene by animals. Any disturbances must be noted.
The crime scene investigator should take photographs and video recordings immediately before anything is moved. ‘Stepping plates’ may be used to secure a route to the body and preserve evidence. Notes and a sketch should also be made at this time. The deceased’s location relative to other objects and structures within the scene is very important. The actual position of the deceased is plotted: the head and crutch are good points on the body to use for plotting its position. Accurate measurements and relative proportions must be noted to place items accurately within the scene in sketches made at the scene. Great care should also be taken to preserve any footwear marks or other significant evidence types around the body.
The deceased is the most valuable piece of potential evidence at any death scene. Hence, a systematic and thorough examination of the body should be under-taken at the scene. Blood, weather conditions, location and poor lighting may mask faint injuries and trace evidence on the body; therefore the crime scene investigator should document in writing, by sketch and by photographic recording all information about the body that can be gathered at the scene. The remainder will have to wait until the postmortem examination. The attendance of other experts at the scene may also be considered, e.g. biologist, entomologist, etc.
The environment in which the body was found will affect the rate of body cooling. The wind conditions, temperature and the presence of any rain should be noted. The crime scene investigator will need to develop a general description of the deceased, including, where possible, the gender, race, age, height and weight.
One of the first most important questions that needs answering is: Did death occur at this locus? The position in which the deceased was discovered is of particular importance, as it will provide an indication as to whether or not the body was moved before being discovered. The presence or absence of rigor mortis or stiffness of the body, absent, minimal, moderate, advanced or complete, will help the crime scene investigator and the pathologist determine if the person died at that locus, in the position, as found. The crime scene investigator should inspect the body for postmortem lividity, hypostasis, or livor mortis. A pink-purple discoloration is usually present at the lowest point of the body. This is due to the settling of the blood by gravitation. Its location and state of fixation should be noted and photographed. For example, unfixed livor mortis blanches white when moderate pressure is applied, as opposed to fixed livor mortis, which remains the same color when pressure is applied. If livor mortis is noted on the deceased in areas not consistent with it forming in the lowest parts of the body, the crime scene investigator should consider the possibility that the deceased was moved after death.
The blood flow patterns should match the position of the body. If the scene is one of apparent violence, the blood flow patterns can indicate the use of a weapon.
Is there trace evidence at the scene consistent with the death having occurred at this locus? Does the body contain any trace evidence that is unusual for this locus; for example, mud on soles of shoes and/or grass and/or seed material found on the clothing when the body has been located inside a house? Is the death one that can be attributed to natural causes? Is there any external sign of violence? Is there anything amiss or out of the ordinary with the scene? Is there anything about the scene that arouses the crime scene investigator’s suspicions?
The crime scene investigator should consider several hypotheses and then set out to prove or disprove each one. The physical evidence present, togther with the known facts, should be sufficient to enable the crime scene investigator to develop a reasonable hypothesis as to what has happened at the scene; however, this is not always possible. Suspicions may not be aroused until the postmortem examination reveals something that was not apparent at the scene. The pathologist may, however, provide the investigator with a definitive indication as to the cause of death, giving the investigators leads to start their lines of inquiry.
Before the deceased is moved from the scene, the crime scene investigator should begin the examination of the body systematically, noting and photographing trauma and locating and removing potential trace evidence that may be lost on moving the body. The taking of body swabs and tape lifts may be considered at this stage. The deceased’s hands, feet and head should be bagged using paper bags, as the use of plastic and any subsequent refrigeration will cause plastic bags to sweat. The bags should be large enough to be taped securely around the wrist, ankle or neck and allow ‘ballooning’ over the area to be protected. The body should then be placed into a new, clean body bag. If face down, it should not be turned over in this process in order to avoid ‘flooding’ wounds and thus damaging evidence. A thorough examination of the area that was previously obscured by the body may now be conducted. The deceased should then be transported to the mortuary for a full postmortem examination.
The postmortem examination is normally conducted by an experienced forensic pathologist. The crime scene investigator should be present, as will the investigating officer or his or her delegate.
The deceased should be taken from the body bag and all packaging items should be retained for a subsequent search for trace evidence in the forensic science laboratory. The crime scene investigator should then record photographically the clothing and the condition of the body, and take a facial photograph for use in identification processes. The forensic pathologist should be taking notes and making diagrams.
The clothing should be inspected and any obvious trace evidence removed and packaged. Each item of clothing should be removed and packaged separately. It is at this time that wallets and property should be removed from the deceased’s pockets and the contents noted and the items packaged. It may well be that these are of no forensic value, as such, and thus may be released into the custody of the investigating officer. All items of clothing should remain in the custody of the crime scene investigator.
An external examination should take place next. Questions may already exist that need answers. Are there any marks of violence, such as stab or gunshot wounds, ligature marks, or restraints, injection sites, or blunt injury wounds? Are these injuries incompatible with life, or could the person have lived and moved for a time after sustaining the injuries, thus explaining some of the evidence located at the scene? Could the deceased have inflicted the injuries? Were there other persons involved? Do the injuries appear to have been made antemortem, at the time of death or postmortem? Bleeding into the tissues (bruising) usually means that the deceased was alive at the time of the injury. Are there any injuries that could be regarded as ‘defense’ wounds? These would indicate that the deceased was alive, alert and aware that he or she was being assaulted and aware of the life-threatening nature of the assault.
The crime scene investigator should search the body using oblique lighting. This is a method of highlighting minute particulate matter and/or bruising that, under normal lighting, is difficult to see.
At this stage of proceedings, the forensic pathologist should take fingernail scrapings, with each digit’s scrapings being placed into a separate labeled container. The next samples to be obtained are hair samples, which should be recovered from a site of interest and packaged. These samples should remain in the custody of the crime scene investigator. A complete series of radiographs should then be taken. These may reveal broken bones, projectiles, foreign bodies, prostheses that have been inserted into the person while alive, and major deformities.
Identification may be an issue. Identification is important in both civil and criminal law. It provides proof of the person’s death. It allows for:
• notification of next-of-kin;
• eventual disposition of the remains;
• completion of the death certificate;
• settlement of the deceased’s estate;
• identification in criminal proceedings.
Visual identification, although the most frequently used method of identification, is subjective and can be unreliable as many people bear resemblances to each other. The person making the identification can also be so shocked by seeing the deceased that he or she can make a false identification owing to being in a state of denial. Scientific identification techniques may also be employed, including:
• A general description of the deceased: color of hair and eyes, height, the presence of scars, marks and tattoos.
• A general description of the clothing: type and color of each item.
• A forensic odontologist should attend the mortuary before the postmortem examination begins to chart and cast the teeth and to take what radiographs may be necessary for later comparison purposes.
• DNA samples (see below).
• Contents of the deceased’s wallet.
• A medical records search for any major operation, broken bones or the addition of any prosthesis fitted during life, if a name can be suggested for the deceased.
• The last issue to be dealt with before the deceased is released is that he or she be fingerprinted. A fingerprint technician should attend the mortuary, take inked impressions from the deceased’s hands, classify them and search for a match through their fingerprint files.
The pathologist continues with the postmortem examination, during which items of interest are recorded by the pathologist in his notes and diagrams, and photographically by the crime scene investigator, who should use a scale rule with any close-up photography. It is also at this stage of the postmortem examination that samples should be taken for blood grouping and DNA profiling, alcohol determination and drug and poison screens. Samples should also be taken for histopathology and microbiology if the forensic pathologist thinks that these are necessary.
Violent crimes typically result in a great deal of physical evidence being deposited on the deceased and the suspect. A thorough search should be made of the deceased or living suspect for any evidence, which may be expected to be extremely transient and easily destroyed or contaminated. Depending on the type of crime, for example shooting, stabbing, rape/murder or blunt injury beating, different forms of evidence may be present. Additionally, the specific area on the body in which the evidence is found is of extreme importance; for example, dried semen in the pubic hair of a deceased female, or firearm discharge residue on around the entry point to the chest is indicative of a contact wound. Consideration may also be given to other experts attending the postmortem examination (e.g. firearms expert).
In crimes of violence the crime scene investigator should insist on the taking of blood and other biological samples for grouping and DNA analysis; and blood, vitreous humor and urine for alcohol levels.
After all the information is to hand from the crime scene and the postmortem examination, those involved should be able to work out the cause and manner of death from the facts available. Although modern forensic investigation is advanced, there will be times when the crime scene does not provide information and the postmortem examination does not reveal a definitive cause of death. These are the difficult cases.