Forensic Dna Identification From Human Remains Submerged In


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Forensic Dna Identification From Human Remains Submerged In

  1. 1. Forensic DNA Identification from Human Remains Submerged in Water By Cheryl M. Lowe April 29, 2009
  2. 2. Background <ul><li>There are many incidences where human remains end up in water </li></ul><ul><li>What are the distinguishing features of human remains found in water? </li></ul><ul><li>Is there a difference between salt water and fresh water in regard to DNA preservation? </li></ul>
  3. 3. Background <ul><li>There are many factors that affect the integrity of DNA evidence from remains found in water </li></ul><ul><li>Limited research so far on how long DNA can be preserved in water </li></ul>
  4. 4. Definitions <ul><li>Seawater = water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5%, or 35 parts per thousand </li></ul><ul><ul><li>The density of surface seawater ranges from about 1020 to 1029 kg·m -3 , depending on the temperature and salinity </li></ul></ul><ul><li>Fresh water = naturally occurring water on the surface such as bogs, ponds, lakes, rivers and streams and underground in aquifers and underground rivers </li></ul><ul><ul><li>Low concentrations of dissolved salts </li></ul></ul><ul><ul><li>coastal areas freshwater may contain significant concentrations of salts derived from the sea if windy conditions have lifted drops of seawater into the clouds </li></ul></ul>
  5. 5. Total Molal Composition of Seawater (Salinity = 35) <ul><li> Component Concentration (mol/kg) </li></ul><ul><li>H 2 O 53.6 </li></ul><ul><li>Cl - 0.546 </li></ul><ul><li>Na + 0.469 </li></ul><ul><li>Mg 2+ 0.0528 </li></ul><ul><li>SO 4 2- 0.0282 </li></ul><ul><li>Ca 2+ 0.0103 </li></ul><ul><li>K + 0.0102 </li></ul><ul><li>C T 0.00206 </li></ul><ul><li>Br - 0.000844 </li></ul><ul><li>B T 0.000416 </li></ul><ul><li>Sr 2+ 0.000091 </li></ul><ul><li>F - 0.000068 </li></ul>Source:
  6. 6. Remains Submerged in Water <ul><li>Favorable conditions for adipocere </li></ul><ul><li>Increased saponification due to exposure to excess of water </li></ul><ul><li>Cells absorb water until rupture, then release fatty contents that are then hydrolyzed and hydrogenated </li></ul><ul><li>Adipocere is common in remains found in bathtubs, ponds, lakes, oceans </li></ul><ul><li>Bloating, skin slippage, wrinkling of hands and feet common </li></ul>O’Brien, et al.
  7. 7. Remains Submerged in Water <ul><li>Tissue loss from: </li></ul><ul><ul><li>Effects of the water current </li></ul></ul><ul><ul><li>Chemical composition of water </li></ul></ul><ul><ul><li>Industrial waste water </li></ul></ul><ul><ul><li>Predation by insects, marine animals, fish </li></ul></ul>O’Brien, et al.
  8. 8. Body at 4 weeks O’Brien, et al.
  9. 9. Body at 7 weeks O’Brien, et al.
  10. 10. Body at 12 weeks O’Brien, et al.
  11. 11. Stages of adipocere formation on a body floating in water for 3 months Stage I – 4 Float, bloat, ovapositioning and hatching Stage II 4–6 Early: insect activity, skin sloughing, cutis anserina, residue formation on water surface Stage III 6–8 Early: adipocere formation, microbial growth, color loss; Increased: insect activity, skin sloughing, cutis anserina, residue formation on water surface Stage IV 8–10 Increased: adipocere formation, microbial growth; Advanced: insect activity, cutis anserina, color loss, residue formation on water surface Stage V 10–12 Advanced: adipocere formation, microbial growth; Reduced: insect activity O’Brien, et al.
  12. 12. Case Example – Fresh Water <ul><li>Decomposed remains found in a dam on the Seine River after 3 years </li></ul><ul><li>Successful recovery of DNA profiles using Profiler Plus kit from bone (10 STR loci and amelogenin) </li></ul><ul><li>No results from saponified sternocleidomastoid muscle </li></ul>
  13. 13. Case Example – Fresh Water
  14. 14. Case Example – Fresh Water
  15. 15. Case Example – Salt Water <ul><li>Skeletonized remains found in 2 rubber boots in March 2005, 145m deep in the Southern Australian coast (Great Australian Bight) </li></ul><ul><li>DNA analyses on reference samples from relatives of fishermen who had disappeared in the area </li></ul><ul><li>Victim identified with Profiler Plus kit as a 52 year old prawn fisherman, swept off of boat about 10 years earlier </li></ul>
  16. 16. Case Example – Salt Water <ul><li>DNA stability maintained by low light conditions, cold temperatures, alkaline pH of the ocean floor (pH was between 7.5 and 8.5) </li></ul>Byard, et al.
  17. 17. Case Example – Salt Water <ul><li>Remains found relatively preserved within rubber boots </li></ul><ul><li>Wedges of bone from distal ends of each tibia were submitted for DNA analysis </li></ul><ul><li>Homicide with dismemberment was considered as a possible scenario </li></ul><ul><li>Possibility of drifting of remains along the ocean floor…could have come from coastal areas </li></ul>
  18. 18. DNA Profiles Obtained Byard, et al.
  19. 19. DNA Stability in Water <ul><li>DNA integrity can be preserved under the following conditions: </li></ul><ul><ul><li>High mineral content of water: high amounts of calcium, magnesium, carbonates, sulfides, sulfates </li></ul></ul><ul><ul><li>Anaerobic environment: limits oxidative damage of DNA, as well as bacterial and fungal growth </li></ul></ul><ul><ul><li>Neutral pH: around 6.1 to 6.9, buffered from presence of carbonates </li></ul></ul><ul><ul><li>Low oxygen tension </li></ul></ul>
  20. 20. DNA Stability in Water <ul><li>From 1984 to 1987, there were 177 ancient individuals of all ages recovered from Windover pond, Florida Atlantic Coastal Ridge </li></ul><ul><li>Intact crania with pieces of preserved brain matter </li></ul><ul><li>Pond possessed favorable conditions for DNA preservation; preliminary Southern blot showed traces of human DNA </li></ul>
  21. 21. Discussion <ul><li>Water can preserve DNA evidence in most cases </li></ul><ul><li>The most important factor in the recovery of DNA evidence from submerged remains seems to be time </li></ul><ul><li>However, it can sometimes complicate data…especially in mass disaster investigations (Southeast Asian tsunami) </li></ul>
  22. 22. Conclusions <ul><li>DNA identification by itself is not fully reliable from human remains found in aqueous environments </li></ul><ul><li>Important for other metadata to be incorporated, such as dental identification, anthropological studies </li></ul><ul><li>Further research needs to be done </li></ul>
  23. 23. Bibliography <ul><li>Crainic K, Paraire F, Leterreux M, Durigon M, Mazancourt P. Skeletal remains presumed submerged in water for three years identified using PCR-STR analysis. J Forensic Sci, Sept. 2002, Vol. 47, No. 5. (1-3) </li></ul><ul><li>Byard RW, Both K, Simpson E. The identification of submerged skeletonized remains. American Journal of Forensic Medicine and Pathology. March 2008, Vol. 29, No. 1, pages 69-71. </li></ul><ul><li>O’Brien TG, Kuehner AC. Waxing grave about adipocere: soft tissue change in aquatic context. J Forensic Sci, March 2007, Vol. 52, No. 2, 294-301. </li></ul><ul><li>Herrmann Bernd, Susanne Hummel. Ancient DNA: Recovery and Analysis of Genetic Material from Paleontological, Archaeological, Museum, Medical, and Forensic Specimens . Springer, 1994. Pages 105-106. </li></ul><ul><li>Graw M, Weisser HJ, Lutz S. DNA typing of human remains found in damp environments. Forensic Science International 113 (2000) 91-95. </li></ul><ul><li>Pacher J, Cameron J. Submersion cases: a retrospective study 1988-1990, Med. Sci. Law 32 (1992) 15-17. </li></ul><ul><li>Swann H, Spafford N. Body salt and water changes during fresh and sea water drowning, Texas Rep. Biol. Med. 9 (1951) 350-384. </li></ul>
  24. 24. Questions?