Summary
This project involves an investigation at the crime scene (CS) where Jessica was killed during an after-
party. Based on the pieces of conviction, several sub-investigations were conducted with the goal of
gathering valuable information about this evening. We conducted a study to determine the genetic
polymorphisms of CYP2C9 and VKORC1 in the DNA from the victim with the aim of demonstrating
possible warfarin sensitivity. Molecular typing of CYP2C9*1, CYP2C9*2, CYP2C9*3, VKORC1-1639
G/G, VKORC1-1639 G/A and VKORC1-1639 A/A was performed by PCR-RFLP (polymerase chain
reaction-restriction fragment length polymorphism). The potentially present SNPs (single nucleotide
polymorphism) cause or eliminate cut sites for the enzymes AvaII, kpnl, and NciI. The size of the
resulting fragments then leads to a particular genotype. Various tests were also performed on the
underpants of the victim to show whether sexual contact had occurred. For this purpose, body fluids
(in particular saliva and semen) were detected using the polilight, phadebast test and cytological
staining. If semen and/or saliva is present, the stain will absorb and light up at wavelengths between
450-500 nanometer (nm). Using the polilight at different wavelengths, the spots that will be studied
further, were visualized and named. The phadebas test was performed for the detection of amylase
in the stains. For this purpose, a sample was smeared over a filter and in the presence of amylase,
the starch-bound blue dye in the filter will be released. In order to determine what specific type of
bodyfluids are involved, de samples were stained according to the method of the Papanicolaou (PAP)
stain and the Hematoxylin and eosin (H&E) stain. With the H&E staining, the nucleus and cytoplasm
stain pink/purple and the sperm cells purple. In PAP staining, the cytoplasm turns pink, orange and
blue. The nucleus and sperm cells turn blue. By viewing the stained samples under a microscope is
revealed what kind of cells are present and from which body fluids the stains originate. As the final
part of the semen study, a polymerase chain reaction with the markers MUC1 and opa 4-RAPD
(Random Amplified Polymorphic DNA) was performed on the DNA of the semen cells from the
underpants, separated and isolated by differential extraction, and the DNA of the suspects to show a
possible match when the band pattern is the same. To find out who may have been at the CS, a
microscopic comparative hair examination was performed between the hairs of the CS and those of
the references. If there is a match, the external and internal characteristics will be the same.
Therefore, the hairs were examined under the microscope and general characteristics such as length,
color, medulla, cortex and the special features were determined. In these studies, we found that the
victim is heterozygous *1/*2 for the CYP2C9 gene and heterozygous G/A for the VKORC1 gene. For
the underpants, the stains were imaged using the polilight at 450 nm and 490 nm and indicated
saliva and or semen. The phadebas test showed a blue color change in all stains and indicates
amylase. Furthermore, the cytological staining under the microscope showed sperm and saliva. The
MUC1 and RAPD markers gave no result and did not provide a band pattern for comparison.
However, the comparative hair examination indicates that possibly Floor ter Beek and Senna de
Vreede have a hair that matches one found on the CS. From the findings of the warfarin examination,
it can be concluded that the victim is sensitive to warfarin and therefore this may have possibly
contributed to her death when a reduced dose was not taken. The examinations on the underpants
show that there was sexual contact, but not with whom. In addition, possibly Floor ter Beek and
Senna de Vreede were at the CS leaving a hair behind.