E. Detailed Guidelines on the Analysis of Skeletal Remains 1. Introduction 274. These Guidelines describe the process to be followed in the analysis of skeletal remains. 2. Infrastructure for the analysis of skeletal remains 275. The analysis of skeletal remains requires infrastructure, in particular a laboratory. In terms of security, chain of custody and biosecurity, the laboratory is set up in the same way as a mortuary. The laboratory should be used exclusively for the analysis of skeletal remains as ordinarily it takes longer than an autopsy (sometimes days or even weeks) for the analysis to be completed. The following list sets out some of the basic conditions required. These will vary depending on the number of cases under analysis at any one time: (a) Sufficient space to place the tables where the remains will be analysed. The tables should be large enough to lay out skeletal remains anatomically (b) Good lighting (c) Good ventilation (d) Areas for the deposit and storage of remains and associated evidence (refrigeration is not required for skeletonized remains) (e) Cleaning area (with access to running water) (f) Photography area (g) Area for taking samples for genetic analysis (this needs to take into account potential crosscontamination issues) (h) Access to plain X-rays (i) The availability of exhaust air filtration to address odours and the accidental dispersal of infectious materials, spores, etc. (j) When the body is in an advanced stage of decomposition, a special room for removing flesh to allow the bones to be examined. 3. Preparing skeletal remains for analysis 276. The importance of properly recovering the remains cannot be overemphasized. Failures in recovery further complicate an already complicated task, and may render it impossible to produce reliable and valid conclusions concerning all of the issues to be addressed in the analysis of the remains. 277. After receiving the remains at the laboratory, and following all the steps relating to chain of custody and documentation, the forensic anthropologist must establish: (a) Whether or not the remains are human (b) Whether the case is one of medico-legal interest, and not one relating to a historical or pre-historical context (c) What is the minimum number of individuals represented by the remains. 278. In cases of very fragmented remains it may be difficult to establish macroscopically whether or not the remains are human. If so, histological, genetic or chemical methods should be used. 279. In some cases it is critical to establish if the remains are of medico-legal interest, as they could date from historical or prehistoric times. In those situations, the method of disposal of the remains, the associated objects (e.g. stone tools) found with the remains and their position inside the grave may play a key role in the assessment. Also, certain features of the bones (e.g. strong muscle insertions) and teeth (extreme dental wear) may indicate their historical nature. Such features need to be interpreted with care, however, as contemporary populations may also show such features. The presence of dental restorations will, obviously, indicate a more contemporary context. 280. If the remains have arrived at the laboratory commingled, a proper strategy for sorting them is required in order to establish what is called the Minimum Number of Individuals (MNI) present. Possible approaches include: pair-matching, articulation, process of elimination, osteometric comparison, taphonomy and, finally, genetic analysis. 281. Once established as a case of forensic interest, the remains should be prepared in the following sequence: (a) Inventory: Which bones and teeth are present, the condition of these individual elements, and whether there is more than one individual (identified by repetition of same bones/teeth) 49