Forensic File #1 • What is the first question an investigator needs to ask when they think they have found blood at a crime scene?
Forensic File #1 • Is it really blood? • Is it human blood? • Who’s blood is it?
Today’s assignments • Reading assignment on front table • Presumptive blood lab- table 4 • Animal blood lab- look at slides on table 3
Blood Questions to be answered: • Is it blood? • Is it human blood? • Whose is it? • Determine blood type, alcohol content, drugs present • Determine the method(s) in which blood may have been deposited
You should have back in your folder: • Toxicology binder check (18 pts) • Toxicology test
Serology Unit • Day Two- Blood components and typing
Forensic File #2 • A murderer thinks that they can wash away all signs of blood by using everyday household cleaners and then painting over the spots with new paint. • Will this work? Explain your answer.
Presumptive Tests for Blood • Kastle-Meyer color test--phenolophthalein and H2O2are mixed together; the blood’s hemoglobin will cause the formation of a deep pink color • Luminoltest--reaction with blood; results in the production of light
Human vs Animal • Microscopic survey • Characteristic Differences
Animal Blood Frog Blood • Larger nucleic red blood cells
Human Blood • Numerous non-nucleic red blood cells--5 to 6 million per mm3 • Larger but less numerous white blood cells • Tiny, cellular fragments called platelets • WBC- leukocytes • RBC- erythrocytes • Platelets- thrombocytes
DUE TODAY • Presumptive Blood detection reading • Detection of Blood lab • Animal/Human blood microscopic comparison • Today’s assignments: • Blood type probability problems • Blood Basics webquest