5thEuropeanIABPAconferenceFinal programm

The 5 th European
Internaonal Associaon
of Bloodstain Paern Analysts
(IABPA) Conference
Rome 2015
Influence of impact velocity, fluid depth and
free space on the crown growth of the impact
mechanism and its implications for BPA
Theresa Stotesbury ‐ Trent University
Abstract
We have all come to know and love the
impact pattern at one point or another
in our BPA careers. Our research looks
at the basic dynamics of the impact
mechanism before the blood creates the
static patterns that are routinely processed
at crime scenes. We use highspeed
videos of an impact to investigate
the influence of impact velocity, fluid
depth and free-space on the characteristics
of the mechanism itself. Our work
primarily focuses on the changes in
crown growth for both blood and water
time. This presentation will cover our
observed qualitative and quantitative
comparisons in crown shape and size
under a range of impact conditions. We
demonstrate that the point of maximum
crown size is where most of the droplets
form. This is different from what is traditionally
defined as the point of origin.
Our findings from this study provide an
experimental explanation for the oftenreported
underestimates in CPx and
overestimates in CPz in area of origin
estimation studies.
Biography
Theresa Stotesbury is a Ph.D. candidate in the
Materials Science program at Trent University
in Peterborough, Ontario, Canada. Her project
aims to use silicon colloid chemistry to create
safe and artificial blood substitutes that can be
used for crime scene reconstruction and BPA
research. She is the recipient of the prestigious
Vanier Scholarship held by doctoral students
attending Canadian universities. Previous to
embarking on her Ph.D. at Trent, Theresa completed
her M.Sc. in Forensic Science at the
University of Auckland in New Zealand and is
also a B.Sc.F.S. graduate from Trent.
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