Jodie Warren
Assistant Professor
Department of Justice Studies
Current Research Activities
Currently I am examining the development rate of a Northern Californian species of
blow fly, which can be used to estimate the post-mortem interval (PMI), time since
death occurred, in local death investigations. Insects recovered from a body can be
used to estimate the PMI because the early arriving insects are attracted to the remains
where they lay eggs immediately following death. The time it takes to reach a development
stage is applied as an estimated time since death occurred but while accurate, it
is not precise. In addition to estimating PMI by development stage, my lab completes
research to add precision and estimates to the day within a stage using hyperspectral
reflectance.
Besides forensic entomology, the science of insects as they apply to law, a second
project I will soon begin is to, similarly, use light reflectance to age bloodstains.
Although insects are the best means to estimate PMI beyond 72 hours, insects may have
been delayed or prevented from reaching the remains and in those situations, if there
are bloodstains at the scene, then estimating time of blood deposition could provide
a substitute for an estimated time since death. Aging bloodstains not only assists
with death investigations but places a person at a scene at a specific time. DNA from
blood indicates that a person was there at some point in time but is not definitive
as to when so if bloodstains are aged to the time of deposition then they can indicate
whether the blood depositor was present during the commission of a crime.
Research Connections to Current Events
Estimating the post-mortem interval or time since blood deposition contributes to
police investigations by focusing investigative resources to the correct time frame
such that witness and suspect statements can be confirmed or refuted. These types
of evidence cannot only assist with current cases but can be used in wrongful conviction
cases.
Forensic entomology was key to reversing the wrongful conviction case of Kirsten Blaise
Lobato. Eighteen year old Lobato was twice convicted in the brutal death of Duran
Bailey and served 16 years before the Innocence Project became involved in her case.
In support of the Innocence Project, three forensic entomologists testified that
by there not being any insect activity on the cadaver, this suggests that the death
occurred in the evening the body was discovered since flies do not colonize remains
at night. Had the entomology evidence been used in the first two trials, it is likely
that Lobato would have been found innocent since she had an alibi for that evening
and no other evidence pointed to her. People of lower socio-economic status and people
of color are disproportionately represented in the prison population and African Americans
make up 50% of wrongful conviction cases but only make up 13% of the population. If
these and any forensic sciences can contribute to righting our past wrongful convictions,
then it is our obligation to use science to do that.
Personal Connections to Research
My experience in forensic science began when I heard that a forensic scientist at the university was looking for volunteers in her lab. Since I had just completed a biology degree, I contacted Dr. Anderson and she brought me onboard. In the meantime, I was really quite enjoying the laboratory work so I began working on an advanced specialty certificate in forensic science and technology with honors at nearby British Columbia Institute of Technology. While working on this certificate I also began human death investigation casework. It was at this point when Dr. Anderson asked me to do my Master’s degree with her. I then went on to complete a Ph.D. The forensic science courses that I enrolled in over the years were really what drew my interest in all the different areas of forensic science. Since becoming involved in the science, I have become moved by the alarming number of wrongful convictions in the judicial system which often disproportionally punishes the poor and people of color for crimes they did not commit.
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Keywords
post-mortem interval;forensic entomology; dipteran immature development;
hyperspectral remote sensing;aging bloodstains
