Q. 1. Observe the preliminary results presented for case scenario 1. What do these results suggest for each sample? Using all resources available to you, provide a possible explanation for the light blue color change observed with the sample obtained from the rifle? Which samples would you test further, what tests would you conduct and what information would you hope to obtain? Q. 2. A red brown stain that was positive for the o-tolidine / H2O2 screening test, has been collected from a vehicle that has been parked in Florida for three months during the summer. The police want to know if the stain is human blood. What factors may have caused adverse effects on the evidence? Q. 3. A positive result using the o-tolidine and hydrogen peroxide screening test for blood in conjunction with a positive result indicating the presence of human DNA is used as proof that human blood is present, in some jurisdictions. Devise a simple scenario that could disprove this assumption. Q. 4. Using any resources available to you describe how the ABAcard Hematrace test works. What is its sensitivity? What is the high dose hook effect?
