FRSC 202 Lecture Notes - Lecture 8: Abo Blood Group System, Karl Landsteiner, Serology
Document Summary
Today"s message: the body is dna"s way of making more dna . Body fluids: common biological evidence left at crime scenes. Saliva (spitting, mouth contact: have class rather than individuating characteristics (e. g. abo blood types, contain dna (individuating) One trait 10% + second trait 10% + Ab [ab only] 3: percentages can vary by region and ethnicity. Vertical blood drops = drips from 90 degree angle. Transfer stains = blood on second object that touched bloody object: head-to-ground-to-sandal, head-to-book-to-hand-to-robe. Impact spatter due to blunt force: results form already- bloody object (body) receiving a blow. Impact spatter due to gunshot: smaller in size (1mm in length), with misty appearance. Other types: arterial spurts (cut artery, expirated blood (cough, sneeze, altered (mixed with other fluids or matter, insect activity etc. ) Concerns: contamination, lab errors, misrepresentation of statistics, discounting of other evidence (e. g. prior probability of suspect being at rime scene, planting of evidence or other acts of tampering, fraud, etc.