Biography
Sara Gale is a geophysical archaeologist working for Geophysical Survey Systems, Inc. as the archaeology and forensic application specialist as well as providing technical training on the use of GPR for a variety of applications. She is a registered professional archaeologist with an M.A. from the University of Denver, who’s spent over a decade applying geophysical methods to archaeology. Sara has worked with the Georgia Bureau of Investigations to identify buried evidence and burials and she has also provided training to crime scene investigations at the Henry C. Lee Institute of Forensic Science
Abstract
Ground-penetrating RADAR (GPR) is a non-invasive geophysical method used to identify and map everything from rebar in concrete to artic glaciers. Since the early 1980s it’s also been used on crime scenes to find clandestine burials and buried evidence. This poster will provide an introduction to GPR in identifying clandestine burials as well as address some of the challenges in applying this technology in the field
Biography
Irina Perepechina is a Professor of Department of Criminalistics of Legal faculty of Lomonosov Moscow State University. She has both Medical and Legal Education, PhD degree (1990) and Doctor of Medicine degree (2003) in Forensic Medicine (Genetic Identification). Her scientific interests focus on fo¬rensic DNA analysis, DNA evidence interpretation, DNA database, DNA phenotyping, forensic serology; legal aspects, theory and methodology of forensic science/medical law. She has more than 140 scientific publications and manuals. She is also a Member of the International Society for Forensic Genetics (ISFG), INGO in 1995-1999 also representative of Russian Federation in DNA WG of ENFSI. At the University she lectures forensic medicine, criminalistics, forensic genetics and forensic science
Abstract
The precision of DNA identification with a certain locus set is typically measured with the frequency P of allele combination occurrence in a population. If the decision is made solely on the basis of DNA analysis results, it would always be the non-zero probability of justice failure due to mistaken identity. Therefore, for every case in hand we have to provide rationale for the critical value Pmax of identification precision which can be assessed as sufficient for the judgment. We employ the notion of the average utility from the decision theory to obtain the closed form expression Pmax=ln (1+x)/(V-1) where V is the estimate of the number of potential suspected persons and x=(a+b)/(c+d). Here ‘a’ is the utility gain when an offender is convicted, ‘b’ is the utility loss when an offender is acquitted, ‘Ñ’ is the utility loss when an innocent is convicted by mistake; and ‘d’ is the utility gain when an innocent is acquitted. The value of ‘x’ reflects the adoption level by the society of justice failure in the considered case or a group of similar cases. The adoption level is a function of the society which needs to be elicited from a special poll. A possible question of the poll is the following decision problem: “Imagine you definitely know an innocent was convicted as a result of a justice mistake. You can secure an acquittal to this accused person but several convicted criminals (certainly guilty) will also be released from prison. How many criminals (1, 2, 5, 10 etc) would you release to save the innocentâ€? Then the maximum number ‘n’ of criminals released gives x=1/n. We provide examples of calculation of the critical frequency Pmax.