LEC13 - DNA II (Forensic Science) PDF

DNA II LEC13 Friday November 1st FRSC2030H Foundations in Forensic Science  LAB04 Forensic Entomology Course Update Test II Final Exam Saturday December 14th @ 11AM Sources of DNA Gel Electrophoresis Method of separating DNA...

DNA II LEC13 Friday November 1st FRSC2030H Foundations in Forensic Science  LAB04 Forensic Entomology Course Update Test II Final Exam Saturday December 14th @ 11AM Sources of DNA Gel Electrophoresis Method of separating DNA based on size Agarose gel center contains wells Buffer solution throughout Charged anodes DNA travels down the gel based on size Combined DNA Index System (CODIS) Primer Annealing 1990s 13 Loci + Amelogenin 2018 20 Loci + Amelogenin Multiplexing Allows for the simultaneous extraction and amplification of specific combinations of STRs Many different commercial kits available DNA Mixtures Amelogenin Gene for tooth pulp Located on both X & Y chromosome Y-STR markers characterized Mixtures often occur Examines phenotypes on only the Y chromosome Complex mixtures Possible identification of multiple male sources Note about inheritance Mitochondrial DNA Nuclear DNA present in Nucleus 23 pairs of chromosomes Each parent contributes 50% Mitochondria Power plant of cells Contain own DNA mtDNA (plasmid) Used when no DNA available Maternally inherited Cytochrome c Highly conserved in species Wildlife DNA Involve Wildlife crimes Trafficking Poaching Habitat destructions Illegal Hunting Natural Resources DNA Profiling and Forensic Centre (NRDPFC) Located at Trent University Handles cases year-round Genetic Genealogy Genealogical databases Publicly available databases GEDmatch 23 and me, Ancestry.com Identity-by-decent (IBD) Shared DNA from ancestry Third cousin or closer relation Privacy concerns Public vs private databases Case Study – East Area Rapist 1976-1979 50 separate home invasions and rapes 1978 – First murder of a couple 1979-1986 – Nightstalker 11 more murders DNA found at some Communication Letters / poems Phone calls Case Study – East Area Rapist 2017 DNA uploaded to GEDmatch Large family tree was created from results 2 potential suspects 2018 DNA sample of suspect was collected from vehicle & tissue from garbage Arrested, charged and shortly convicted Plead guilty to murders Case Study – Christine Jessop Murder 1984 9yr missing Oct. 3rd Dec. 31st body found Guy Paul Morin Suspected early in the case Arrested and charged with murder in April (1985) Acquitted in first trial (1986) Re-tried (1992) Acquitted (1995) due to DNA evidence Case Study – Christine Jessop Murder Kaufmann Report (1996) Evidence – Microscopic hair and fibre evidence Evidence was associative only! Limitations and explanation of evidence Scientists must be trained to talk in court Materials should have been kept for re-analysis Police More training Avoiding tunnel vision! Notebooks Video/audio taping interviews Case Study – Christine Jessop Murder October 5th 2020 DNA was examined using Genetic Genealogy Identified Calvin Hoover 28 at the time of murder Suicide 2015 Friend of the Jessop’s family Never questioned by police