1. The wounds suffered by the victim in a hit and run pedestrian homicide provide important clues regarding the course of events (Rao, 2013). Wounds can include bruising, road rash, other skin abrasions and lacerations, broken bones, internal injuries, and compression injuries. The location and extent of these help determine the direction from and speed with which the pedestrian was hit, the position of the pedestrian, and the size of the vehicle.
The three types of injuries should be observed separately (Rao, 2013). These include primary impact injuries, caused by the first object that strikes the pedestrian; secondary impact injuries, caused by the vehicle after the first strike; and secondary injuries, caused by other objects (such as the road) striking the pedestrian. Some of the details are described below.
Legs often receive the brunt of the primary impact as they are hit by the bumper (Rao, 2013). A strike from behind may cause the pedestrian to fall backward and strike his/her back against the vehicle, causing a fracture-dislocation of the spine; or the head to hit the windshield. A strike while the pedestrian is facing the vehicle may cause abdominal and chest injuries. In either case, s/he may then hit the ground, which can cause severe head injuries. Leg injuries at different heights or of different severities on the two legs can indicate that the pedestrian walked or ran in front of the vehicle, which suggests a possible suicide. When hit by the side of a vehicle, there may be fractured ribs and internal organ rupture, as well as tearing from objects such as mirrors and door handles. If the pedestrian is run over, tire marks may be visible, as well as crush injuries, which may indicate that the victim was already injured, perhaps ejected from a vehicle, and lying in the road before a following car ran over the body. The height of the various injuries can help identify the size and thus identity of the vehicle. Clearly, the body can communicate much information about how the damage was done.
2. Sudden infant death syndrome (SIDS) is diagnosed by first ruling out other causes of death. As such, it is likely a category that includes more than one cause of death, such as a variety of subtle vulnerabilities that can cause an infant to stop breathing. Researchers have detected possible causes or contributing factors including decreased serotonin levels, decrease in the hair cells of the inner ear (which play a role in respiration), dehydration and infection. One promising line of research is Kinney et al.’s investigation of the dentate gyrus of the hippocampus (2014). They found abnormalities in this area in 43% of infants who died from SIDS. These same researchers had previously found serotonin abnormalities in the brainstem. Both areas are involved in the automatic control of respiration. The researchers are investigating the relationships between these areas to determine if in combination they are a single cause of SIDS, or if they are two separate causes leading to the same tragic result.
Before SIDS can be diagnosed, however, a complete examination of the death scene and forensic autopsy need to be done to rule out other possible causes of death; most notably child abuse, but also known causes such as infection. The investigator should take detailed notes, video and photographs of the death scene. EMS and any others present should be interviewed immediately to determine if and how the body has been moved. Additional interviews should be done with extended family and childcare providers to obtain their observations. Healthcare providers should be interviewed and the infant’s medical records thoroughly reviewed, both to rule out medical causes such as infections and to determine if there is evidence of child abuse in retrospect.
Medical records and/or complete autopsy may reveal findings suggestive of child abuse such as old evidence of bruising, bite marks, bone fractures, and/or traumatic brain injury. Many visits to doctors with unexplained illnesses in the child suggest Munchausen by proxy. Head injuries, retinal hemorrhage, and lethargy before death may reveal shaken baby syndrome. Suspicion is higher if more than one child in a single family has died of SIDS or other incompletely explained causes. If all the above, unfortunately too common, causes are ruled out, then the medical examiner can diagnose SIDS.
3. Carboxyhemoglobin is a molecule formed by hemoglobin and carbon monoxide in the blood. When carbon monoxide is inhaled, some of it will bind to hemoglobin; in fact, it binds more easily than oxygen does. This may occur in an environment with high levels of air pollution or in a fire. The amount of carboxyhemoglobin versus other compounds determine whether deaths were due to oxygen deprivation alone or due to other toxins in the air (Birky, Malek, & Paabo, 1983).
In 1981, the MGM Grand Hotel in Las Vegas had a serious electrical fire that resulted in the deaths of 85 people and injuries to hundreds more (Birky, Malek, & Paabo, 1983). The sprinkler system was reasonably effective, so only four died with severe burns. One jumped and died from skull fractures. One died later of postexposure myocarditis. However, a faulty ventilation system resulted in smoke and toxic fumes that spread even to the upper floors of the hotel. Therefore, the other 79 were determined to have died from smoke inhalation and/or carbon monoxide. This fire clearly demonstrated that smoke inhalation was more dangerous and more likely to be fatal than fires and burns themselves, and resulted in changes in safety protocols.
The above researchers, at the request of the coroner, reexamined blood samples from the MGM fire for carboxyhemoglobin, among other compounds, four months after the fire. Carboxyhemoglobin values in the samples were found to be less than 50% in a plurality of the victims. Carboxyhemoglobin levels of about 70% were considered necessary for lethality. Therefore, they concluded that 66% of the deaths from the MGM Grand fire were due to inhalation of other toxins. The exact toxins could not be determined. However, large amounts of synthetic materials burned in the fire. Several elements, including heavy metals, were found in soot in the lungs of the victims.
4. If two children were left in an abandoned well after playing hide and seek, died in two days but had no evidence of injury, exposure, starvation or dehydration, then they must have died from some form of asphyxia. Possibilities include drowning in well water, inhaling some sort of gas concentrated in a small space, inhaling dirt or other powder that can clog the airways, or mechanical compression.
Many wells are small enough for children to get stuck, so the children may not have had space to breathe properly. If they were stuck in awkward positions, they may not have been able to free themselves enough to inhale adequately. Determination of the exact cause of asphyxia would have to wait for examination of the death scene and complete autopsy to provide more information.
India has had multiple deaths of children from falling into wells, usually due to lack of oxygen (Tilak, 2012). The unsafe wells are due to several areas of India suffering from water shortages. Thus, the government has made it illegal for people to drill wells, which only makes the situation worse; but then several gangs drill illegal wells in order to sell the water to hard-hit areas. When water is not found or the well runs dry they just leave, rather than capping the wells to ensure safety as required by law. Thus India has had multiple fatalities of children of all ages from well accidents, despite aggressive rescue efforts. The cause of death in most of these dry wells has been asphyxiation. Others have been the result of injuries from falls, not pertinent in our case.
5. From the information given, it is possible that the woman shot while sunbathing died of either a contact shot or a distance shot. The amount of damage done by a bullet, such as its ability to pierce the femoral artery, is determined by the velocity of the bullet (Frost & Denton, 2015). Thus a high-velocity bullet shot at a distance can do just as much damage as a low-velocity bullet shot up close. Possibly more, although it will lose some velocity over the course of its travel. However, we can determine the distance of the shot from more detailed description of the appearance of the wound.
Contact wounds have a thick ring of soot around the entrance wound, made up of partly burned powder, metal, and other debris. This debris explodes out of the gun barrel upon firing. The heat of released gases sear the soot into the skin, making it impossible to completely wash this soot away.
On the other hand, the “ring of dirt” is from bullet wipe. This is debris that the bullet picked up on its way through the barrel of the gun, such as oil, powder, dirt, soot, and so on. Although it may end up transferred from the bullet head to the victim’s skin, it is a very thin line of gray/black discoloration at the rim of the wound, not the thick and cooked deposit of debris exploding onto the skin with a contact wound. The two markings have quite a distinctive appearance (Frost & Denton, 2015).
- Birky, M., Malek, D., & Paabo, M. (1983). Study of biological samples obtained from victims of the
MGM Grand Hotel fire. J. Anal. Toxicol., 7, 265-271. Available from
http://www.ncbi.nlm.nih.gov/pubmed/6559221 - Frost, R.E., & Denton, J.S. (2015). Forensic pathology of firearm wounds. Medscape. Retrieved from
http://emedicine.medscape.com/article/1975428-overview#a1 - Kinney, H.C., Cryan, J.B., Haynes, R.L., Paterson, D.S., Haas, E.A., Mena, O.J., . . ., Trachtenberg,
F.L. (2014). Dentate gyrus abnormalities in sudden unexplained death in infants: Morphological
marker of underlying brain vulnerability. Acta Neuropathol., 129 (1), 65-80. Retrieved from
http://link.springer.com/article/10.1007/s00401-014-1357-0/fulltext.html#CR24 - Rao, D. (2013). Road traffic collisions. Forensic Pathology. Retrieved from
http://www.forensicpathologyonline.com/E-Book/injuries/road-traffic-collisions - Tilak, S.G. (2012). India’s wells of death. Al Jazeera. Retrieved from http://www.aljazeeracom/indepth/
features/2012/06/201262518453409715.html
