Q. Let's go back if we could. You mentioned the substrate control. What is that?
A. A substrate control is basically to test an item or fabric to make sure that the chemical presumptive test is not giving a false positive.
Q. What do you mean by that?
A. Meaning a positive result is given by a substance other than blood, the chemical presumptive test for blood.
Q. Are you using these substrate controls to allow a later analyst to determine if the jacket itself has something in it, as opposed to the blood staining, providing any later genetic information?
A. That is correct.
Q. Did you take these substrate controls from areas immediately adjacent to each of the stains?
A. Yes, I did.