DNA from Burned Bone: The application of ancient DNA methods to forensic DNA recovery

As submitted by the proposer: DNA from burned remains presents a special challenge to medico-legal investigations. Fragments of burned remains are often not amenable to standard DNA recovery and identification. This impacts victims of house, car or forest fires, of mass disasters, and of murder with the attempt to conceal cause of death and/or identification of the victim. The proposed project will partner researchers at the Arizona State University with the Maricopa County Office of the Medical Examiner for the purpose of assessing new methods for application to forensically derived samples of burned bone, tooth roots, and dental calculus. Specifically, our goals are to address the following aims: 1) assess how different degrees of charring/burning affect DNA recovery for different skeletal elements using different extraction methods, 2) examine the success rate of the recovered DNA in CODIS STR analysis, and 3) investigate the extent of fragmentation and damage in both mitochondrial and nuclear DNA recovered from different tissues with different levels of burning and examine how this impacts NGS sequencing and SNP data quantity and quality. The samples will be obtained from victims of house and car fires that are investigated by the Medical Examiner’s Office in Maricopa County, Arizona. For each case, we will evaluate the skeletal tissues and classify them into five levels of burning prior to DNA analyses. We will test three extraction methods, using these to collect three types of evidence (CODIS-STRs, the complete mitochondrial genome, and 1,000 genome-wide single nucleotide polymorphisms). The comparisons made in the proposed study will be important for creating a predictive model for determining which samples from incinerated skeletal remains are likely to produce the best results given the extent of charring and other visible signs reflecting level of burning. This project will have immediate, real-time implications for the criminal justice community. Every medical examiner and Coroner jurisdiction carries unidentified remains, some of which are from individuals who died as a result of fire or whose cause of death and/or identity was concealed by fire. Note: This project contains a research and/or development component, as defined in applicable law. ca/ncf