In cases of forensic dental identification, a key factor in the comparison of the dental status of deceased persons with antemortem dental records is the matching of dental restorations in individual teeth. Many studies have been performed showing the prevalence of dental interventions. This has mostly been performed by counting the numbers of decayed, missing and filled teeth (DMFT) in each mouth without detailed data collection on a per-tooth basis. The purpose of this study was to investigate the research question: to what extent would data on the distribution and prevalence of restoration types in the human dentition facilitate forensic identification? A database program was developed to allow efficient collection and collation of dental trait information. Provision was made for storing information relating to a subject's individual teeth, such as restorative materials used and surfaces filled. Other data, such as missing teeth, caries status on a per-individual tooth basis and presence and details of types of prostheses may be stored. iii Data from patients attending a private group practice in Hobart was collected and a system was devised to enable the likelihood of dental trait occurrence to be calculated in cases of forensic dental identification. The capabilities of the system are demonstrated in a series of mock cases of dental identification. An opportunity to make use of the database for which it was designed arose in relation to the analysis of person identification evidence in a murder trial at the Tasmanian Supreme Court. The use of this reference database in evidence invoked lengthy debate involving the judge, crown prosecutor and defence barristers. The resulting voire dire was resolved in favour of conclusions drawn from the use of the database being admitted in evidence. The legal precedent set in the Marlow trial may possibly offer encouragement for practising odontologists to further the concept of establishing and using reference databases of dental traits in population groups in other parts of Australia.

In cases of forensic dental identification, a key factor in the comparison of the dental status of deceased persons with antemortem dental records is the matching of dental restorations in individual teeth. Many studies have been performed showing the prevalence of dental interventions. This has mostly been performed by counting the numbers of decayed, missing and filled teeth (DMFT) in each mouth without detailed data collection on a per-tooth basis. The purpose of this study was to investigate the research question: to what extent would data on the distribution and prevalence of restoration types in the human dentition facilitate forensic identification? A database program was developed to allow efficient collection and collation of dental trait information. Provision was made for storing information relating to a subject's individual teeth, such as restorative materials used and surfaces filled. Other data, such as missing teeth, caries status on a per-individual tooth basis and presence and details of types of prostheses may be stored. iii Data from patients attending a private group practice in Hobart was collected and a system was devised to enable the likelihood of dental trait occurrence to be calculated in cases of forensic dental identification. The capabilities of the system are demonstrated in a series of mock cases of dental identification. An opportunity to make use of the database for which it was designed arose in relation to the analysis of person identification evidence in a murder trial at the Tasmanian Supreme Court. The use of this reference database in evidence invoked lengthy debate involving the judge, crown prosecutor and defence barristers. The resulting voire dire was resolved in favour of conclusions drawn from the use of the database being admitted in evidence. The legal precedent set in the Marlow trial may possibly offer encouragement for practising odontologists to further the concept of establishing and using reference databases of dental traits in population groups in other parts of Australia.

Iris recognition is a validated and non-invasive human identification technology currently implemented for the purposes of surveillance and security (i.e. border control, schools, military). Similar to deoxyribonucleic acid (DNA), irises are a highly individualizing component of the human body. Based on a lack of genetic penetrance, irises are unique between an individual’s left and right iris and between identical twins, proving to be more individualizing than DNA. At this time, little to no research has been conducted on the use of postmortem iris scanning as a biometric measurement of identification. The purpose of this pilot study is to explore the use of iris recognition as a tool for postmortem identification. Objectives of the study include determining whether current iris recognition technology can locate and detect iris codes in postmortem globes, and if iris scans collected at different postmortem time intervals can be identified as the same iris initially enrolled. Data from 43 decedents involving 148 subsequent iris scans demonstrated a subsequent match rate of approximately 80%, supporting the theory that iris recognition technology is capable of detecting and identifying an individual’s iris code in a postmortem setting. A chi-square test of independence showed no significant difference between match outcomes and the globe scanned (left vs. right), and gender had no bearing on the match outcome. There was a significant relationship between iris color and match outcome, with blue/gray eyes yielding a lower match rate (59%) compared to brown (82%) or green/hazel eyes (88%), however, the sample size of blue/gray eyes in this study was not large enough to draw a meaningful conclusion. An isolated case involving an antemortem initial scan collected from an individual on life support yielded an accurate identification (match) with a subsequent scan captured at approximately 10 hours postmortem. Falsely rejected subsequent iris scans or "no match" results occurred in about 20% of scans; they were observed at each PMI range and varied from 19-30%. The false reject rate is too high to reliably establish non-identity when used alone and ideally would be significantly lower prior to implementation in a forensic setting; however, a "no match" could be confirmed using another method. Importantly, the data showed a false match rate or false accept rate (FAR) of zero, a result consistent with previous iris recognition studies in living individuals. The preliminary results of this pilot study demonstrate a plausible role for iris recognition in postmortem human identification. Implementation of a universal iris recognition database would benefit the medicolegal death investigation and forensic pathology communities, and has potential applications to other situations such as missing persons and human trafficking cases.