Methods that May Be Used for the Estimation of Time since Death - Case Study Example

Methods that may be used for the estimation of time since death Grade (April 28th, Methods that may beused for the estimation of time since death Introduction Murders, suicide, accidents, assassinations and other forms of targeted killings are some of the most complex puzzles to unravel, considering that most of these causes of death are associated with some of form of hidden evidences, so that the perpetrators of the offences cannot be detected easily. Therefore, without the possibility of estimating the time that has elapsed since the occurrences of such deaths, it would be very difficult to unravel the actual details and circumstances surrounding the death, thus making it even harder to detect the possible culprits. Therefore, the estimation of the time since death is very essential, since it enables the investigators to narrow down their investigation to a given time frame, which makes it easier to investigate the circumstances that surround such deaths and the possible causes (Newberry, Lewis & Walters, 2004:936). Further, the accurate estimation of the time since death is also crucial for enabling the investigators to narrow down to a narrow range of suspects associated with the death, owing to the fact that, when the time since death is known, then it is easy to know the immediate individuals that were associated with the victim, as opposed to when the time since death is unknown (Payne-James, 2003:93). Therefore, this discussion seeks to analyze the various methods that may be used for the estimation of time since death, with a view to critically assessing the merits and demerits of each of these methods. First, the discussion will explain the different methods applicable in estimating the time since death. Secondly, the discussion will tackle the merits associated with each method. Thirdly, the discussion will present the demerits associated with each method. Finally, the discussion will be summed up by a conclusion, which will recap the important points of the discussion, state limitations associated with the discussion and raise the necessary questions, if any. Discussion There are various methods that can be applied to estimate the time of death of an individual, depending on the environment where the body is found, the evidence available and the nature of the cause of death (Szelecz, Fournier, Seppey, Amendt & Mitchell, 2014:671). The different methods that can be applied to estimate the time since death include: Body core temperature This is a method applied to estimate time since death, through the measurement of the core temperature of the body, relative to the temperature of the surrounding environment where the body is found, also referred to as the ambient temperature (Warther, Sehner, Raupach, Püschel & Anders, 2012:402). The formula applied under this method is 37.5oC - 1.5 oC, which equates the body temperature to the ambient temperature through the application of the principle; that the body loses temperature at the rate of one-and-a-half degrees per hour after death (Zelic, 2013:1285). Therefore, depending on how the ambient temperature is high or low, it may take some time for the body temperature to equate this temperature, which then serves to measure the time that the body has been lying in that environment (Anders, 2013:127). However, it is important to note that the level of dead body temperature loss may be slowly than the estimated rate of one-and-a-half degrees per hour, where the body has been exposed to an extremely cold environment, such outdoors, in a coolant, on ice, refrigerator or in the river (Boulagnon & Gillery, 2011:67). The brain and the liver are the two main organs that are applied to estimate the time since death under this method, owing to their high mass and density, which accurately sustains the core temperature of the body (Davis, 2013:15). Further, the rectum is also applied to estimate the time since death under this method, especially under homicide ad rape cases, since it can be applied simultaneously with DNA identification (Hawksworth & Wiltshire, 2011:7). The level of precision under this method is ±1.5 hours for the first 16 hrs after death, when the brain or the liver is used as the organ to assess time since death and ± 2.8 hrs where the rectum is used (Henssge & Madea, 2007:184). The precision and the level of confidence then decline after 16 hours for the brain and the liver assessment, and after 24 hour for the rectum assessment. Merits of the Body core temperature method of estimating time since death The merit associated with this method of estimating the time since death is that; it is a scientific method that applies a well elaborate formula to arrive at the findings (Janjua & Rogers, 2008:22). In this respect, the Body core temperature is suitable for estimating the time since death, considering that it has a high level of precision compared to other methods, since the body core temperature loss from the brain and the liver is consistent, such that the margin of error in this method is very low (Kanz, Reiter & Risser, 2014:613). Therefore, when the Body core temperature is applied to estimate the time since death for a dead body, the confidence interval is ±1.5 hours, as long as the method is applied within the first 16 hours of death (Kastenbaum, 1999:279). Additionally, the merit associated with this method is that it presents a high level of precision, since the measurement of the core body temperature can be undertaken on a range of body organs, such as the brain, the liver and the rectum (Knight, 1997:36). This allows for multiple body core temperature evaluations, which in turn increases the rate of precision, as opposed to circumstances where only a single vital organ could be applicable. Demerits of the Body core temperature method of estimating time since death The major demerit that is associated with the Body core temperature method of estimating time since death is that, it is only found to give precise results when the method is applied within the first 16 hours of death (Leinbach, 2011:772). In this respect, this method is time bound, and thus it may not be applicable under situations where the circumstances surrounding a death are much hidden, such that the body is discovered several days after. The margin of error in this method keeps increasing with the passage of time, with the level of confidence in time estimation since death after 16 hours increasing to ± 4.1 hr (Madea & Rödig, 2006:87). The other major limitation associated with this method is that, despite the use of a scientific formula to estimate the time, the conditions and the environment under which the body is found may render the formula inapplicable (Magni, Borrini & Dadour, 2013:413). This is because, when the body is found exposed to extremely cold environmental conditions such as dumping in a river, in a refrigerator, a coolant, icy ground, windy climate or outdoor under rainy and wet conditions, the body could lose its core temperature at a rate lower than one-and-a-half degrees per hour (Magni, Borrini & Dadour, 2013:417). This simply means that the application of the formula will not give accurate results. Further, the accuracy of this method is limited by various physiological body factors, where the rate of loss of the core body temperature will vary depending on the amount of body fat, the amount of blood that has been lost by the victim, and the amount and the type of clothes worn by the victim (Mao, Fu, Seese, & Wang, 2013:236). In this respect, the accuracy of the formula may be limited, since the rate of loss of the core body temperature may not remain at one-and-a-half degrees per hour (Mao, Fu, Seese, & Wang, 2013:237). Rigor mortis This is another method of estimating the time of death, which applies the body natural process of stiffening of the body muscles after death (Martinez, Duque & Wolff, 2007:182). After the death of an individual, there are various chemical imbalances that arise, which then define the nature of the contraction and the relaxation of the body. The rigor process, which entails the stiffening of the muscles starts with the smaller muscles, and then works downwards towards the larger muscles. In this respect, the facial and skin muscles will stiffen first (Mathur & Agrawal, 2011:277). The rigor process starts two hours after death, and can last between 24 and 30 hours, allowing the estimation of the time since death, depending on the nature of stiffness of the body at the time of assessment (Mathur & Agrawal, 2011:282). Therefore, this method is commonly used to estimate the time since death, within the first 36 to 48 hours of death. Merit The merit associated with this method of estimating the time of death is that; it applies a natural process that is common with every individual, thus capable of delivering standard results during all assessments (Newberry, Lewis, & Walters, 2004:935). The method applies the rule of thumb that if the body is still flexible and warn, he death occurred within the past 3 hours, if it is warm and stiff it has been dead for between 3 to 8 hours and if the body is stiff and cold, then it has been dead for between 8 and 36 hours (Payne-James, 2003:93). Further, the method is associated with the merit of simplicity, such that it can be applied locally by informed individuals, since it is not highly based on scientific principles, but more oriented to the natural process of death. Demerit The demerit associated with the application of rigor mortis as the method for estimating time since death is that, it is a crude method of estimating time, which is only based on delivering a range of time, with little precision on the actual time that has elapsed since death (Knight, 1997:72). Thus, this method can only give a range of between 1-3 hours, 3-8 hours and 8-36 hours, without any precision on the exact time lapse since death. Therefore, this method cannot be useful under circumstances where there is a need to narrow down to a specific time since death, such as under conditions of intentional killing investigations (Payne-James, 2003:97). Forensic Entomology This is the other method that can be applied in the estimation of time since death, which entails the study of the insects that are found at the scene of death (Yan-Wei, Xiao-Shan, Hai-Yang & Run-Jie, 2009:425). Under this method, an insect forensic expert or pathologist can establish a more accurate time scale of the time since death, depending on the insects that will be found at the scene of death, and the life cycle of such insects during the time of assessment (Yan-Wei, Xiao-Shan, Hai-Yang & Run-Jie, 2009:427). Dead bodies are known to attract two types of insects; flies and beetles (Zelic, 2013:1286). Flies and beetles can be found at the scene of the dead body in different lifecycle states, ranging from eggs to larvae or maggots, pupae and adults (Yan-Wei, Xiao-Shan, Hai-Yang & Run-Jie, 2009:425). However, the adult stages are not important for determining the time lapse, compared to the other stages of the lifecycle, which defines how long the body could be laying on the scene (Zelic, 2013:1288). Merit The merit associated with Forensic Entomology as a method of estimating time since death is that the method is scientific, reliable and accurate, since it gives accurate time frame, based on the lifecycle of the insects found on the body (Yan-Wei, Xiao-Shan, Hai-Yang & Run-Jie, 2009:427). Further, Forensic Entomology gives more information related to the nature of death, such as whether the body had been killed elsewhere and moved; if the insects found on the body are not found in the area naturally (Henssge & Madea, 2007:183). Further, depending on where the insects are fond to have accumulated, the nature of death could be defined, since they accumulate on the wounded areas (Hawksworth & Wiltshire, 2011:7). Demerit The major limitation associated with the application of this method for estimating the time since death is that; it requires time for insects to develop through different stages of the lifecycle, thus the Forensic Entomology method cannot deliver immediate results (Yan-Wei, Xiao-Shan, Hai-Yang & Run-Jie, 2009:426). Additionally, the method is highly prone to the changes in the weather pattern, since the lifecycle of different insects is different based on the seasons, meaning that the accuracy of the method can be hampered by weather patterns (Janjua & Rogers, 2008:17). Further, depending on the nature of the interference of the corpse, such as drugging or chemically-based killing, the insects may not produce a predictable lifecycle pattern, which then interferes with the accuracy of the method (Hawksworth & Wiltshire, 2011:9). Conclusion Estimating the time since death is an important aspect of death investigations, since it helps to narrow down to the specific time of death, and the possible suspects involved. There are three major methods applied in the estimation of time since death, namely body core temperature, rigor mortis and forensic entomology. Each method has its own strengths and weaknesses. The limitation of this discussion is that it has omitted several other methods of estimating time since death such as lividity and body decomposition process assessment, due to the space limitation. Nevertheless, the major question that arises from the discussion is, can the three methods be combined in estimating time since death, to overcome the limitations associated with each method, and thus give accurate results or would that be too costly and time consuming? References Anders, S. (2013). Estimation of the time since death-reconsidering the re-establishment of rigor mortis. International Journal Of Legal Medicine, 127(1), 127-130. Boulagnon, C. & Gillery, P. (2011). Post-mortem biochemistry of vitreous humor and glucose metabolism: an update. Clinical Chemistry & Laboratory Medicine, 49(8), 65-70. Davis, B. (2013). Study of Modes of Identification, Cause of Death and Time since Death in Cases of Decomposed Bodies: A Prospective Study. Indian Journal Of Forensic Medicine & Pathology, 6(1), 13-17. Hawksworth, D. L., & Wiltshire, P. J. (2011). Forensic mycology: the use of fungi in criminal investigations. Forensic Science International, 206(1-3), 1-11. Henssge, C., & Madea, B. (2007). Estimation of the time since death. Forensic Science International, 165(2/3), 182-184. Janjua, M. A., & Rogers, T. L. (2008). Bone weathering patterns of metatarsal v. femur and the postmortem interval in Southern Ontario. Forensic Science International, 178(1), 16-23. Kanz F, Reiter C, Risser D. Citrate Content of Bone for Time Since Death Estimation: Results from Burials with Different Physical Characteristics and Known PMI. Journal Of Forensic Sciences (Wiley-Blackwell) [serial online]. May 2014;59(3):613-620. Kastenbaum, R. (1999). Looking death in the eye: another challenge. Omega: Journal Of Death & Dying, 40(1), 279. Knight, B., (1997) Simpsons Forensic Medicine, Edward Arnold, London. Leinbach, C. (2011). Beyond Newtons law of cooling - estimation of time since death. International Journal Of Mathematical Education In Science & Technology, 42(6), 765-774. Madea, B., & Rödig, A. (2006). Time of death dependent criteria in vitreous humor—Accuracy of estimating the time since death. Forensic Science International, 164(2/3), 87-92. Magni, P., Borrini, M., & Dadour, I. (2013). Human remains found in two wells: a forensic entomology perspective. Forensic Science, Medicine & Pathology, 9(3), 413-417. Mao, S., Fu, G., Seese, R. R., & Wang, Z. (2013). Estimation of PMI depends on the changes in ATP and its degradation products. Legal Medicine, 15(5), 235-238. Martinez, E., Duque, P., & Wolff, M. (2007). Succession pattern of carrion-feeding insects in Paramo, Colombia. Forensic Science International, 166(2/3), 182-189. Mathur, A., & Agrawal, Y. K. (2011). An overview of methods used for estimation of time since death. Australian Journal Of Forensic Sciences, 43(4), 275-285. Newberry, J. E., Lewis, K. J., & Walters, M. B. (2004). Estimating time since death of Picea glauca × P. engelmannii and Abies lasiocarpa in wet cool sub-boreal spruce forest in east-central British Columbia. Canadian Journal Of Forest Research, 34(4), 931-938. Payne-James, J. (2003). Forensic medicine: Clinical and pathological aspects. San Francisco [u.a.: Greenwich Medical Media. 93 Szelecz, Ι., Fournier, B., Seppey, C., Amendt, J., & Mitchell, E. (2014). Can soil testate amoebae be used for estimating the time since death? A field experiment in a deciduous forest. Forensic Science International, 23690-98. Warther, S., Sehner, S., Raupach, T., Püschel, K., & Anders, S. (2012). Estimation of the time since death: post-mortem contractions of human skeletal muscles following mechanical stimulation (idiomuscular contraction). International Journal Of Legal Medicine, 126(3), 399-405. Yan-Wei, S., Xiao-Shan, L., Hai-Yang, W., & Run-Jie, Z. (2009). Seasonality of insect succession on exposed rabbit carrion in Guangzhou, China. Insect Science, 16(5), 425-439. Zelic, K. (2013). Forensic or Archaeological Issue: Is Chemical Analysis of Dental Restorations Helpful in Assessing Time Since Death and Identification of Skeletonized Human Remains?. Journal Of Forensic Sciences (Wiley-Blackwell), 58(5), 1284-1288. Read More