The Value of Presumptive Screening of Physical Evidence

Authors & Contributors

    Presumptive tests for blood, seminal fluid, urine, and saliva are fast, relatively inexpensive, and can quickly eliminate a stain from further analysis if the results show the sample is not the fluid originally suspected. Likewise, microscopic analysis of hair is a nondestructive test involving minimal preparation and can confirm if hair is human in origin and determine if a particular hair is suitable for nuclear DNA analysis. Both time and money can be saved by efficiently eliminating samples from further analysis when it is deemed unnecessary by a presumptive method. This webinar was designed for police and attorneys involved in cases with physical evidence. During this webinar, our presenters discussed the advantages of microscopic and presumptive screenings of physical evidence, especially suspected bodily fluid stains and hair prior to advancing to more expensive DNA analysis. They also provide examples of such screenings and discussed how these screening methods can save valuable time, money and resources by eliminating samples from being forwarded onto unnecessary further analysis.

    Highlighted Topics Covered:

    • The advantages of microscopic and presumptive screening of physical evidence prior to expensive DNA analysis
    • How these screening methods can save time, money and resources by potentially eliminating unnecessary further analysis
    • The importance of proper packaging of evidence collected at the scene to ensure it is not compromised prior to analysis