master forensic science

Master Forensic Science Research Projects 2016-2017

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Research projects 2016-2017

The University of Amsterdam's (UvA) Master's programme in Forensic Science, offered by the Faculty of Science, is unique in the Netherlands. The programme distinguishes itself from most international Master's programmes in Forensic Science by building on a range of scientific disciplines, such as Chemistry, Computer Science, Life Sciences, Mathematics, Physics, and other exact sciences. The goal of the programme is to train good scientists, armed with forensic knowledge and skills.

A part of the curriculum is a six-month internship during which scientific research is executed that is relevant to the forensic field. This document gives an overview of the capabilities of our students and the many ways in which a research project can be conducted.

For more information please contact: [email protected]

Research Projects 2016-2017

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Title Organisation Student Previous education

BIOLOGICAL TRACES Fingermark analysis Page 6 The efficient integration of EVISCAN in casework – Comparison with well-established methods for visualization of evidence

Landeskriminalamt (LKA), Saxony, Germany

Laura Herberg Biology

Chemical profiling of fingerprints using immunolabelling and mass spectrometry: advanced biological information from a biometric perspective

NFI Tayná Witmer Biomedical Sciences

Blood analysis Page 8 Simultaneous quantification of albumin and immunoglobulin G in whole blood, plasma and dried blood spots with element-labelled antibody detection using ICP-MS

Sheffield Hallam University, United Kingdom

Shanna Hogeling Biology

Detection of forensic traces using graphene quantum dots

Netherlands Forensic Institute (NFI), the Hague, the Netherlands

Aishwarya Nagarajan

Biotechnology

MALDI – MS based method validation for the operational detection of blood

Biomolecular Research Centre, Sheffield Hallam University, United Kingdom

Judith Schramm Forensics in Natural Sciences

Bloodstain Pattern Analysis (BPA) Page 11 Influence of surface properties on drop impact of blood

Aix-Marseille University, France

Naomi Buntsma Medical Natural Sciences

Link between bloodstain pattern and impact energy


Claudia Reissner Earth Sciences

DNA analysis Page 13 Next generation sequencing of HID-SNPs in a Somalipopulation sample and a comparison of librarybuilding methods

University of Copenhagen, Denmark

Suzanne van der Heijden

Health & Life Sciences

A presumptive test for assessing DNA quantity in forensic samples using immunolabeling

Academic Medical Center (AMC), Amsterdam, the Netherlands

Nina van de Kerkhof

Biomedical Sciences

Designing a new multiplex assay for the detection of forensically relevant tetra-allelic SNPs using massive parallel sequencing.

Forensic Laboratory for DNA Research (FLDO), the Netherlands

Marije te Raa Biology

The impact of the shedder state on secondary and tertiary DNA transfer

Institute of Legal Medicine, Münster, Germany

Max Schmidt Bioscience

DNA analysis after fire exposure to obtain the applicability and effectivity of extinguishing methods for car fires

Police Amsterdam, the Netherlands

Mandy Wijnings Biology and Medical Laboratory Research


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BIOLOGICAL TRACES (continued) Epigenetics Page 18 Epigenetic discrimination of identical twins under the forensic scenario – Investigating the influence of the DNA source

Erasmus University Medical Center, Rotterdam, the Netherlands

Paraskevi (Vivian) Kalamara

Biology

Forensic medicine Page 19 Age estimation using clinical Computed Tomography (CT) scans

AMC Alondra Diaz Cupa Biology

An experimental approach to the possible biomechanics behind perimortem fracture traits in human skeletal remains.

Universitat Autònoma de Barcelona, Spain

Britt Hevink Biomedical Sciences

Detection of alterations of autophagy related protein LC3-II as a possible method of post mortem age estimation

Institute for Forensic Medicine, Duesseldorf, Germany

Lisa Jansen Biology

The influence of biomechanical bone properties on perimortem traits in human long bone fractures


Carlijn van den Pol Human Movement Sciences

The accuracy of virtual bone models for forensic anthropology

AMC Roy Snijckers Biomedical Sciences

Forensic radiological analysis of typical skeletal fractures in airplane crashes

AMC

Melanie Tijsterman

Health & Life Sciences


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NON-BIOLOGICAL TRACES Criminalistics and forensic statistics Page 25 Weighing secondary characteristics in the DVI process

Police Midden-Nederland

Jessie Poelsma Liberal Arts & Sciences (major in Biology)

Digital forensics Page 26 Camera identification with deep learning

NFI Eleni Athanasiadou

Cultural Technology and Communication

Clothing identification via deep learning: Forensic applications

NFI Marianna Bedeli Applied Informatics

Forensic chemistry Page 28 Chemical analysis of pyrotechnic charges in confiscated illegal fireworks in the Netherlands with capillary electrophoresis

Van ‘t Hoff Institute for Molecular Science (HIMS), Amsterdam, the Netherlands

Lara van Duin Chemistry

Surface Acoustic Wave Nebulisation – Mass Spectrometry for the rapid identification of explosives

HIMS Mariska de Heiden Bio-pharmaceutical Sciences

Toxicology Page 30 Determination of the contact risk of toxic (industrial) chemicals by gas chromatography and ultra-high performance liquid chromatography tandem mass spectrometry

The Netherlands Organization for Applied Scientific Research (TNO), Rijswijk, the Netherlands

Mirjam de Bruin-Hoegée

Chemistry


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BIOLOGICAL TRACES Fingermark analysis

Student Laura Herberg Research carried out at

Landeskriminalamt (LKA), Saxony, Germany

Supervisor Carsten Knopf Title thesis The efficient integration of

EVISCAN in casework – Comparison with well-established methods for visualization of evidence

Abstract The major drawback of the majority of the currently used methods for the visualization of latent fingerprints is their destructive nature. This project focusses on a new device called EVISCAN and its abilities and limitations regarding the investigation of fingerprints in every day case work. EVISCAN provides an optical method for the visualization and securing of (finger-) prints that is contactless and thus allows a subsequent investigation of DNA. Although EVISCAN wasn’t really capable of giving better results than the conventional methods it was able to provide results of a comparable quality in more than 60% of the investigations. The study resulted in a list of objects and materials where EVISCAN was not suitable to replace the conventionally used methods (24%) and a list with such where it represents a facilitation and improvement of everyday casework (76%).

Principle of visualization with EVISCAN: Intensity difference between light reflected by substrate and by fingerprint

EVISCAN 1000


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Student Tayná Witmer Research carried out at

NFI

Supervisor Dr. Marcel de Puit

Title thesis Chemical profiling of fingerprints using immunolabeling and mass spectrometry: advanced biological information from a biometric perspective

Abstract Fingerprint analysis is an indispensable method for identification purposes. An important part of the identification process is the treatment of latent fingerprints in order to visualize the friction ridge pattern. In addition to the ridge pattern, fingerprints hold a wealth of chemical information about the donor in the fingerprint residue. Recent advances have focused on investigating the use of immunolabeling and time of flight secondary ion mass spectrometry (ToF-SIMS) to obtain donor specific chemical information from fingerprints. However, limited research has been done regarding the detection of proteins in fingerprints with ToF-SIMS. Therefore, this study investigated the use of a new method which combines immunolabeling with lanthanide conjugated antibodies and ToF-SIMS analysis to detect the human serum albumin (HSA) protein in the fingerprint residue. HSA was successfully detected in fingerprints following immunolabeling with anti-HSA. Depletion series showed that the amount of HSA in fingerprints is highly variable due to inter-donor variability or deposition related influences. ToF-SIMS analysis of 159Tb lanthanide labelled fingerprints indicated that the amount of 159Tb present in the samples was too low. Consequently, 159Tb, TbCl3 and EuCl3

lanthanide conjugated polymer solutions were evaluated. The EuCl3 polymer solution with the highest concentration had the highest ion counts and signal intensity. Preliminary results showed that the EuCl3 polymer solution could be coupled to the primary anti-HSA antibody. However, it was not possible to label fingerprints with anti-HSAEu as the lanthanide could not be detected in labelled samples with ToF-SIMS analysis. More work is thus needed before the method can yield improved results. Nonetheless, the method has a promising potential as it could allow for the acquisition of chemical information from old or damaged fingerprints and improve the current standards of fingerprint-based donor profiling.

Positive ion image of 159Tb originating from the sample surface of a latent fingerprint.

Fluorescence photograph of fingerprint immunolabelled with anti-HSA and Alexa Fluor® 555.


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Blood analysis

Student Shanna Hogeling Research carried out at

Sheffield Hallam University, United Kingdom

Supervisor Dr Catherine Duckett and Dr Rob Bradshaw

Title thesis Simultaneous quantification of albumin and immunoglobulin G in whole blood, plasma and dried blood spots with element-labelled antibody detection using ICP-MS

Abstract Over recent years, quantification of multiple proteins in body fluids has become increasingly prominent, which is beneficial for the forensic and medical fields. Several techniques have been developed based on conventional ELISA; one of these techniques is analysis of proteins labelled with element-tagged antibodies by ICP-MS in serum, allowing quantification of multiple targets within a single sample. This research aimed to quantify albumin and immunoglobulin G (IgG) levels in plasma, whole blood and dried blood spots using NANOGOLD® and Europium labelled antibodies analysed by ICP-MS. Before the proteins were quantified simultaneously, albumin and IgG concentrations were measured separately and compared to protein levels obtained by ELISA. It was found that protein concentrations for both albumin and IgG obtained with element-labelled antibody detection correspond to those determined by ELISA. Furthermore, albumin and IgG levels measured simultaneously by ICP-MS correspond to concentrations found when the proteins were analysed separately by ICP-MS. Finally, development of this method has provided a positive indication that it can be extended to quantification of additional proteins, which could be related to a disease or give additional information for a forensic protein profile of an individual.

Figure 1. Schematic representation of a NANOGOLD®-labelled antibody complex for detection of albumin.

Figure 2. Schematic representation of a Europium-labelled antibody complex for detection of IgG.


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Student Aishwarya Nagarajan Research carried out at

NFI

Supervisor Dr. Threes Smijs Title thesis Detection of forensic traces using graphene

quantum dots Abstract Amidst the advancement in

nanotechnology, graphene quantum dots (GQDs) have proven to have size dependent electrical and optical properties. These unique properties, interest applications in fields like medicine, digital technologies, pharmacology etc. But the forensic application of GQDs is relatively new. Hence this study shows the potential of GQDs in the detection of blood using Fe3+ as markers. A simple, environmentally friendly synthesis was explored by heating citric acid at controlled temperature and time. The detection of Fe3+ ions, were achieved using dopamine functionalised GQDs (DA-GQDs). The characterization of the GQDs and DA-GQDs was provided by determining the structural and optical properties. The FTIR, showed characteristic carbonyl peak at 1703 cm-1 (pyrolysis product), while the introduction of the amide bond in the DA-GQDs was detected at 1570 cm-1. The GQDs and DA-GQDs have shown optimal fluorescence at excitation wavelength 360 nm and the quantum yield for GQD and DA-GQD was calculated to be 0.04 and 0.02 respectively. The size of the GQDs was determined to be 12-25 nm and the DA-GQD 10-30 nm (accurate size estimation can be done with further investigation). The sensing of Fe3+ with DA-GQDs, was based on the oxidation of the dopamine by Fe3+. It was identified by the reduction (73%) in fluorescence intensity, which was found to be proportional to the concentration of FeCl3. Further investigation with blood, will help to determine the usage of GQDs at the crime scene. Functionalization of the surface of GQDs with other elements may be used to target forensic traces like finger marks, semen etc. This gives GQDs a high potential in the future for the detection of traces at a crime scene.


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Student Judith Schramm Research carried out at

Biomolecular Research Centre, Sheffield Hallam University, United Kingdom

Supervisor Dr. Simona Francese Title thesis MALDI – MS based method validation for

the operational detection of blood Abstract Evidential blood stains are frequently

encountered at crime scenes and can yield valuable information in forensic investigations. Therefore, its detection needs to be corroborated or refuted robustly and reliably. Promising biomarkers are blood-specific proteins which enable the discrimination of blood from other biofluids. A suitable platform for the detection of proteins is proven to be Mass-assistant-laser-desorption-ionisation mass spectrometry. The aim of this study is to validate a published method for the operational detection of blood through MALDI MS based on a proteomic approach. In a bottom-up approach, the peptide mass fingerprint of blood is generated by tryptic digestion and compared to reference libraries established by in-silico digestion of identified blood-proteins. The method´s capability to identify blood and its provenance was tested in a blind study. Human blood could be identified truly, whereas the determination of the blood’s provenance originating from non-human species requires reconsideration with regard to relevant criteria in data evaluation. A statistical evaluation of frequent species-specific blood peptides is suggested as a future approach.

Unknown stain of the blind study


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Bloodstain Pattern Analysis (BPA)

Student Naomi Buntsma Research carried out at


Supervisor David Brutin and Fiona Smith Title thesis Influence of surface properties on drop

impact of blood Abstract In BPA, bloodstains encountered at a crime

scene are analyzed to deduce information useful for crime scene reconstruction. Although various methods have been suggested to reconstruct the path of an elliptical bloodstain, no quick height estimation is available yet for passive drip bloodstains (with an impact angle of 90º). Drop impact phenomena are influenced by several factors, but until now no studies have been performed investigating these influences on the splashing limit of a complex fluid like human blood. This study aims to provide a physical explanation of bloodstains encountered at crime scenes. The role of wettability and surface roughness on the splashing limit of blood drop impact is investigated. The impact of blood drops has been recorded on a variety of surfaces that represent possible crime scene surfaces. The recordings were analyzed and compared to the surface characteristics to identify possible empirical relations. Also, the appearances of the retrieved bloodstains are classified in order to relate the bloodstain appearance to the surface characteristics. It was found that the surface roughness influences the splashing limit of blood drop impact. The bloodstains’ appearances could also be related to surface roughness and their impact velocities, but no change in appearance was found for a different wettability. For a forensic point of view, it can be concluded that in particular the surface roughness is important in relating a bloodstain’s appearance to its impact velocity.


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High-Speed camera recording of a blood drop falling on Linoleum.

Student Claudia Reissner Research carried out at


Supervisor Prof. David Brutin Title thesis Link between bloodstain pattern and impact

energy Abstract Finding a link between the pattern a dried

bloodstain forms and the energy it had at impact could potentially lead to crime scene investigators having information about the impact height of a passive bloodstain. Information hereof include the position of the blood source which might lead to valuable information such as the positioning of the victim - e.g. kneeling/standing - which could negate or confirm possible scenarios such as self-defense. In certain cases, it might also be possible to assign a bloodstain to a specific wound. When increasing the impact height, the morphology of bloodstain changes. The present study aims to identify the transitions between three different morphological regimes on various non-, to semi-porous substrates. It is shown that the kinetic energy at impact and the substrate parameters measured (advancing contact angle θ and Roughness Ra ) seem to influence the morphological appearance. However, additional studies will have to be conducted to find all influencing parameters.


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DNA analysis

Student Suzanne van der Heijden Research carried out at

University of Copenhagen, Denmark

Supervisors Prof. Niels Morling, MD DMSc and Claus Børsting, PhD

Title thesis Next generation sequencing of HID-SNPs in a Somali population sample and a comparison of library building methods

Abstract The Precision ID Identity Panel (previously called HID-Ion AmpliSeqTM Identity Panel) was used to type 109 Somali individuals in order to obtain allele frequencies for the Somali population. These frequencies were used to establish a Somali HID-SNP database, which will be used for the biostatistic calculations in family and immigration cases concerning Somalis. The project was also set out to compare different library building methods to investigate the possibility of using automated library building in forensic genetic casework. In order to do so, the SNP typing of the Somalis was performed using Next-Generation Sequencing (NGS) with three different methods of library building: 1) manual library building, 2) automated library building using the Biomek®3000, and 3) automated library building using the Ion ChefTM. Genotypes obtained with the Precision ID Identity Panel were found to be almost in complete concordance with genotypes obtained with the SNPforID PCR-SBE-CE assay. In seven SNP loci, discordances were observed, of which most were previously described in the literature. This indicates that the Precision ID Identity Panel is suitable for forensic genetic casework. Library building methods were compared based on coverage, locus balance, noise ratio, and heterozygote balance. Ion ChefTM library building was found to give the best results. However, more research is needed to determine whether this is caused by the Ion ChefTM library building method or by the use of the Ion S5TM instead of the Ion PGMTM for sequencing. Biomek®3000 library building was found to perform similarly to manual library building. This argues for the use of Biomek®3000 library building in forensic genetic casework. Automated library building would decrease the workload of the laboratory staff, decrease the risk of pipetting errors, and simplify the daily workflow in the forensic genetics laboratory.

Noise levels for all SNPs with manual library building.


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Standard curve for determining the HMGB1 concentrations of fingermark and blood samples. This standard curve is established based on a quadratic fit through the standards with known HMGB1 concentrations of 0-62.5-125-250-1000-2000-4000 μg/mL.

Student Nina van de Kerkhof Research carried out at

AMC

Supervisor Dr. Annemieke van Dam Title thesis A presumptive test for assessing DNA

quantity in forensic samples using immunolabeling

Abstract Until now, quantification of DNA prior to STR analysis is solely possible within the laboratory, as current DNA quantification methods are laboratory-bound. The recovery and transportation of a biological samples to the laboratory is time-consuming and increases the risk of contamination. A new DNA quantification method that is suitable for on-site analysis will greatly optimise forensic investigation. Such a method provides an indication of a sample’s DNA quantity at the scene of crime, resulting in the recovery of those samples with a higher potential of contributing to the investigation of a crime. In this study, the first step is taken towards the development of an on-site DNA quantification method based on immunolabeling of the DNA-binding protein HMGB1. First, a gold standard for DNA quantification was set by comparing three known DNA quantification methods, NanoDrop, Qubit, and qPCR. Second, this gold standard was used for the quantification of DNA within blood- and fingermark samples in which HMGB1 was detected using ELISA. Comparison of the HMGB1- and DNA quantity within all blood samples combined showed no relation. Based on the results of the ELISA, it was determined that the samples needed a different preparation prior to ELISA. Therefore, three different lysis buffers were studied for their effect on protein- and DNA-extraction from blood samples. The results obtained in this study indicate that a RIPA buffer without SDS might be the best lysis buffer for HMGB1 extraction from forensic blood samples. However, further research including more samples should be conducted to get more reliable results and to better study the relationship between DNA and HMGB1 quantity.

DNA extraction from fingerprints for the determination of the gold standard for DNA quantification


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Student Marije te Raa Research carried out at

Forensic Laboratory for DNA research (FLDO), the Netherlands

Supervisor Professor Peter de Knijff Title thesis Designing a new multiplex assay for the

detection of forensically relevant tetra-allelic SNPs using massive parallel sequencing.

Abstract The focus of this research project was on determining whether forensically relevant tetra-allelic SNPs recently identified using publically available whole genome sequencing data were genuinely tetra-allelic or wrongly called tetra-allelic due to sequence misalignments caused by multi-copy areas in the genome. Furthermore focus was on the design of an assay using these SNPs to detect a minor contributor in a DNA mixture sample. This is often difficult with normal STR analysis because of stutters in the PCR. Massive parallel sequencing (with the Illumina Mi-Seq) was used to sequence the markers in the assay. 22 markers were proven to or suspected to be wrongly called tetra-allelic, leaving the final assay to consist of 19 markers of which 17 have already been proven to be genuinely tetra-allelic. With testing additional samples, it is expected that the remaining 2 markers will also proof to be tetra-allelic. Background amplification of the designed assay was generally below 0.5% (except for chimeras), which creates the possibility that a minor contributor as low as 1 or 2% can be detected. A mixture composition test still has to be performed to confirm this.

Allele frequencies of one of the tetra-allelic SNP markers

Principle of massive parallel sequencing using the Illumina Mi-Seq


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Student Max Schmidt Research carried out at

Institute of Legal Medicine, Münster, Germany

Supervisor PD Dr. Marielle Vennemann Title thesis

The impact of the shedder state on secondary and tertiary DNA transfer

Abstract Various different parameters and circumstances affect the DNA transferability and accordingly the quantity of DNA left, influencing the success of DNA typing. A considerable parameter affecting the DNA transfer is the so-called “shedder” state, which describes an individual’s ability to pick up and deposit DNA. To evaluate this proposition a primary DNA transfer experiment was conducted to classify individuals into corresponding shedder groups, “good shedders” and “bad shedders”. Subsequently, our study aimed to assess the influence of the shedder state on secondary and tertiary DNA transfer: Can DNA of a good shedder be placed on a crime scene by a bad shedder even though the good shedder is not connected to the crime and has not been at the crime scene? To answer this question, two sets of experiments were performed: a secondary transfer and two tertiary DNA transfer studies. Our results show that a shedder state classification was possible for 21 out of 24 participants and that the shedder state seems to have an impact on secondary and tertiary DNA transfer. It was further shown that bad shedders might act as vectors; hence, they were able to transfer excessive DNA quantities from good shedders onto further objects. Moreover, we demonstrate that good shedders can transfer minute amounts of bad shedders’ DNA to further objects. Different activities (friction/touching) did not increase the deposited DNA quantity but affected the contribution of the donors to a DNA mixture. Likelihood ratios were calculated using a fully continuous model (EuroForMix) to verify the presence of the donors contributing to the DNA trace. Parameters like washing of hands and wearing gloves prior to sample collection, time of collection or age of an individual did not affect the shedding capacity in our study and neither seemed to influence the quantity of deposited DNA. Our data suggest that shedding ability might be influenced by sex. The results of our study indicate that indirect transfer of DNA through good shedders as well as bad shedders are possible and may place an uninvolved person’s DNA undeliberately to a crime scene.


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Car fire

Student Mandy Wijnings Research carried out at

Police Amsterdam, the Netherlands

Supervisor Willem Jan Schouten Title thesis DNA analysis after fire exposure to obtain

the applicability and effectivity of extinguishing methods for car fires

Abstract In forensic casework there is noticed that after a liquidation the perpetrator set the car on fire to destroy possible evidence. The fire brigade extinguish these cars with the regular extinguish method, namely high pressure water. The disadvantage of this method is that all the possible evidence flush away out of the car, which makes it impossible to conduct forensic investigation of the car. This research examine the possibility of using alternative extinguishing methods in car fires. In addition, the possibility of obtaining a (full) DNA profile is investigated after fire exposure. In this research bottles and cans with DNA evidence were placed in eight cars and set on fire. Every car was extinguished with another extinguishing method. The results showed that the O-bundle low pressure, Pro-pack and F500 are effective methods to extinguish a car fire. The DNA analysis showed that it is possible to obtain a (full) DNA profile after fire exposure. Although the investigation of a burned car is very hard and takes a long time, it is a worthwhile task to do.


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Epigenetics

Student Paraskevi (Vivian) Kalamara Research carried out at

Erasmus University Medical Center, Rotterdam, the Netherlands

Supervisor Prof. Dr. Manfred Kayser and Dr. Athina Vidaki

Title thesis Epigenetic discrimination of identical twins under the forensic scenario – Investigating the influence of the DNA source.

From the summary

Identifying individuals from DNA for forensic purposes relies on the short tandem repeats (STRs) analysis, which is not informative for individualization where the potential perpetrator or putative father has an identical twin. Studies have shown that monozygotic (MZ) twins have differences in their DNA methylation profiles. The scope of the project was to investigate the effect the DNA source has on epigenetic differentiation of MZ twins under the forensic scenario by analyzing DNA derived from buccal swabs as reference-type samples as well as saliva, and cigarette butts as trace-type samples. Twin-differentiating methylation sites (tDMSs) in one example MZ pair were identified by microarray-based genome-wide DNA methylation analysis in reference-type DNA samples from the buccal swabs. Following various quality control steps, 25 tDMSs were selected and analyzed in trace-type DNA samples from saliva and cigarette butts of the same twin individuals. The applied detection method for trace-type sample analysis was TaqΜan-based, quantitative PCR, which uses methylation-specific probes to detect the methylation status of the markers of interest. This study highlights the importance of the sample source in epigenetic MZ twin differentiation and demonstrates the need for careful validation testing before forensic applications may be considered.

DNA methylation profile of identical twins

Amplification curve of the CpG of interest (blue) and reference gene, Alu (red) by using TaqΜan-based, quantitative PCR.

Enviroment Daily Habits


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Forensic medicine

Student Alondra Díaz Cupa Research carried out at

AMC

Supervisor Kerri Lee Colman Title thesis Age estimation using clinical Computed

Tomography (CT) scans From the summary

Estimation of age-at-death is based on the assessment of bone changes that occur differently with age and sex. Traditional techniques, such as the Complex Method, are subjective, user dependent, and not accurate. Based on the premise that cortical bone and trabecular bone density decrease with age, the changes in Hounsfield units (HU) in clinical CT scans can be used to study age-at-death similarly to the Complex Method. The aim of the present study was to evaluate the composition of the proximal femur in HU by using clinical CT scans, and correlate this to adult age-at death. A total of 112 clinical CT scans (56 females and 56 males) divided into seven age groups were manually segmented, thereafter their HU values were plotted into frequency histograms. Group IV (51-60 y) presents the lowest frequency of HU values corresponding to trabecular bone than the rest of the groups. Groups VI (71-80 y) and VII (81+ y) presents lower frequency of cortical HU values than group IV. These values correspond to the bone mineral density (BMD) in the proximal femora of trabecular and cortical bone. Differences in HU values were observed between males and females, whereas no significant variations were observed when left and right femora were analysed. Age-at-death estimation based on CT scans is possible, as the frequencies of HU values correlate to age.

Figure 1. Sementation of the proximal femur by using Articulus. Selected in brown

is the area of interest, while in red the forbidden area. Four planes are visible: 3D

plane (top left), coronal plane (top right), sagital plane (bottom left) and axial plane

(bottom right).

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Student Britt Hevink Research carried out at

Universitat Autònoma Barcelona, Spain

Supervisor Dr. Assumpció Malgosa and Dr. Ignasi Galtés Title thesis An experimental approach to the possible

biomechanics behind perimortem fracture traits in human skeletal remains.

Abstract Establishing whether a fracture occurred around the time of death remains challenging in the forensic anthropological field. In order to overcome this problem, previous research has established 6 perimortem traits: layered breakage, wave lines, crushed margins, bone scales, flakes and plastic deformation. This research introduces a new experimental approach to gain more knowledge about these traits and specifically whether they are related to intra vitam conditions. Fresh (n=33) and dry human long bones (n=24) were fractured with a rapid load of either 3, 5 or 8kg. To mimic muscle contraction as an intra vitam condition compression was added to half of the fresh bone samples (n=15). The experimental samples were compared to each other, to samples broken with a slow load and to autopsy samples. Results showed that perimortem traits could only be found in fresh bone samples, although some resemblances could be found in 2 dry bone samples. Layered breakage, plastic deformation, wave lines and flakes are not dependent on compression and are thus not intra vitam traits, even though flakes appeared more often when compression was exerted. Crushed margins and bone scales only appeared in samples with compression, which could give an indication that they are intra vitam traits. This study opens the door to more research in the origin of bone scales, crushed margins and flakes, which will hopefully make it easier for the forensic anthropological field to distinguish whether fractures have happened around the time of death.

Perimortem fracture traits. Crushed margins (a), wave lines (b), flakes (c), layered breakage (d) and bone scales (e).


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Student Lisa Jansen Research carried out at

Institute of Forensic Medicine, University Medical Center Duesseldorf, Germany

Supervisor Prof. Dr. med. Stefanie Ritz-Timme Title thesis Detection of alterations of autophagy

related protein LC3-II as a possible method of post mortem age estimation

Abstract The identification of unknown human remains is a frequent task in forensic case work. One highly important aspect is the estimation of the deceased person’s age. Bio-medical basic research revealed age related alterations in the expression of some proteins involved in cellular autophagy processes. This pilot project addresses the question, if such alterations can be used as basis for age estimation. The two aims of this study were (1) to find out if the autophagy marker microtubule-associated protein 1A/1B-light chain 3 (LC3-II) can be detected in post mortem drawn samples of human skeleton muscle and if so, (2) to clarify, if age dependent changes in protein expression can be observed. A suitable protein isolation method was developed. However, western blotting analysis revealed no age dependent alteration in the amount of LC3-II. As a side finding an age dependent decrease of the amount of β-actin was observed. Therefore, LC3-II analysis of muscle tissues seems not to be suitable for age estimation but the decrease of the amount of β-actin might be interesting for further research.

Immunoblotting of the proteins LC3-I, LC3-II and ß-Actin in muscles of three individuals of different age: Each muscle sample was filled in three lanes. f = female.


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Student Carlijn van den Pol Research carried out at


Supervisor Dr. Assumpció Malgosa and Dr. Ignasi Galtés Title thesis The influence of biomechanical bone

properties on perimortem traits in human long bone fractures

Abstract Recently, new perimortem traits were reported that can help estimating the time frame of bony trauma (Fig. 1). In this research the influence of biomechanical properties, the type of fracture and location of fracture on the occurrence of these five traits was examined. The sample consisted of femurs and humeri with perimortem fractures. A 3D scanner was used to obtain the biomechanical properties. The cortical thickness and roundness of the bone influenced the occurrence of bone scales and flakes respectively. Wave lines were influenced by the type of fracture, because they need long, sloping edges to appear. The other factors did not have influence on any of the traits. It could be concluded that the presence of the traits should give more information about the circumstances of the fracture, since their occurrence did not depend on features of the bone itself.

Figure 1. The five perimortem traits found in fractured human long bones: crushed margins, wave lines, flakes, layered breakage and bone scales.


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Student Roy Petrus Maria Snijckers Research carried out at

AMC

Supervisor Kerri Lee Colman Title thesis The accuracy of virtual bone models for

forensic anthropology Abstract In the field of forensic anthropology,

skeletal material is used for the assessment of age, sex, stature, geographical ancestry, diet, pathology and cause of death for any given individual. For the development of identification methods a contemporary and representative reference database of the Dutch population is required, one which is currently lacking. The set-up of a virtual database derived from patient CT scans could provide a solution, as patient data provide a representative sample of the living population. However, patient CT scans in are generally acquired using a low radiation dose and high slice thicknesses which, in combination with the soft tissue present, ultimately reduce the CT image quality. Any methods derived from a virtual database should be valid on virtual bone models, as well as on physical dry bones, as the latter is most frequently used in forensic anthropology. This study tests the accuracy of 3D virtual bone models of the os coxae, derived from patient setting CT-scans, when compared to its physical dry bone counterpart.

Figure 1: Physical dry bone and corresponding virtual bone model of a left os coxae. Landmarks and inter-landmarks distances are displayed.


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Student Melanie Tijsterman Research carried out at

AMC

Supervisor Drs. Bernadette S. de Bakker MD Title thesis Forensic radiological analysis of typical

skeletal fractures in airplane crashes Abstract Skeletal fractures after high-energy trauma

occur often. Fracture patterns can be indicative for the trauma mechanism and therefore contribute to the forensic reconstruction of accidents. Acetabular fractures are uncommon but are known to happen after decelerative incidents like car accidents. This research project was concerned with the description of acetabular fracture patterns in airplane crash victims. Postmortem conventional radiographs and/or CT scans were assessed for 29 victims of small aircraft aviation accidents. Fractures of the acetabulum and surrounding structures (i.e. pelvis, spinal column, lower extremities) were scored according to case report forms. This research showed that acetabular fractures occurred in two-third of the victims of aviation accidents. The location of the acetabular fracture might help in deducing the impact mechanism. We propose that assessment based on postmortem CT is preferred over conventional radiographs, as CT scan images facilitate better 3D interpretation of acetabular fractures.

Fig 2. Conventional radiograph showing a right-sided acetabular fracture (red arrow). Note that the femoral head penetrates through the pelvis.

Fig 1. 3D CT scan reconstruction showing extensive fracturation and telescopic shortening of the legs after an airplane crash.


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NON-BIOLOGICAL TRACES Criminalistics and forensic statistics

Student Jessie Poelsma Research carried out at

Police Midden Nederland, the Netherlands

Supervisor Susanne van Beest Title thesis Weighing secondary characteristics in the

DVI process From the summary

The current DVI process from the Dutch LTFO complies with the internationally set standards, and leads to correct identifications of victims. Nevertheless, the LTFO is always looking to innovate and improve their services. Hence they want to meet the powerful call from society to release names of identified victims more rapidly in case of disasters. Therefore, this study addresses the question on how the quality and speed of the DVI process can be improved. Three secondary identification characteristics were investigated: tattoos, implant serial numbers, and iris scans. Different methods used to compare these characteristics ante and post mortem were evaluated on accuracy and efficiency, against the backdrop of the DVI context. Based on these evaluations, weights were assigned to the characteristics using Bayesian statistics. These evidential values formed the input to a Bayesian network, through which the combined probability of the characteristics occurring could be calculated objectively. This posterior probability forms an objective and reproducible basis to the LTFO’s expert opinion, and makes the evidential value of the characteristics transparent.

Tattoo recognition, breast implant, iris scanning


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Digital forensics

Student Eleni Athanasiadou Research carried out at

NFI

Supervisor Prof. Dr. Ing. Zeno Geradts Title thesis Camera identification with deep learning From the summary

In this paper, a camera identification with the use of deep learning technique is introduced. To identify the various cameras, their characteristic PRNU noise pattern was extracted. In forensic science it is important, especially for child pornography cases, to link a photo or a set of photos to a specific camera. Deep learning is a sub-field of machine learning which trains the computer as a human brain to recognize similarities and differences by scanning it, in order to identify an object. In this paper, AlexNet was modified producing an improved training procedure with high maximum accuracy of 80% - 90%. DIGITS showed to have identified correctly 6 cameras out of 10 with a success rate higher than 75% in the database. However, many of the cameras were falsely identified indicating a fault occurring during the procedure. A possible explanation for this is that the PRNU signal is based on the quality of the sensor and the artifacts introduced during the production process of the camera. Some manufacturers may use the same or similar imaging sensors, which could result in similar PRNU noise patterns. In an attempt to form a database which contained different cameras of the same model as different categories, the accuracy rate was extremely low. This provided further proof of the limitations of this technique, since PRNU is stochastic in nature and should be able to distinguish between different cameras from the same brand. Therefore, this study showed that current CNNs cannot achieve individualization with PRNU patterns. Nevertheless, the paper provided material for further research.

Original photo on the top and the extracted PRNU pattern with scene residue on the bottom.

Results of the model training for Experiment 1 (10 different cameras)


27

Student Marianna Bedeli Research carried out at

NFI

Supervisor Prof. Dr. Ing. Zeno Geradts Title thesis Clothing identification via deep learning:

forensic applications Abstract

Usually, people can be described based on their clothing, which can be considered a visual cue to facilitate the process of identifying individuals. The research project aims to identify people based on the visual information that can be drawn from the attire they wear. Deep learning has been applied in this project in order to train the computer in classifying images with clothing content. Initially, the research involves clothing type classification in a large scale dataset. Unfortunately, the model performs poorly on the large scale dataset. In addition to that, the second part of the research applies clothing attribute classification in a dataset containing popular logos and famous brands images. The results show that the model classifies correctly most of the test images with a success rate higher than 70%. Finally, the research focuses on clothing type classification in footage from surveillance cameras. Interestingly, the system performs above par, labeling correctly the test images with approximately 70% success.

Graphical interpretation of the performance of the model-180 epochs were used. The accuracy plateaus at 75.4% while the loss (val) is 1.9.

Top-5 classifications with their corresponding confidence values for the test image. The model classified correctly with 62.79% prediction for the


28

Forensic chemistry

Student Lara van Duin Research carried out at

Van ‘t Hoff Institute for Molecular Sciences (HIMS), the Netherlands

Supervisor Karlijn Bezemer MSc Title thesis Chemical analysis of pyrotechnic charges in

confiscated illegal fireworks in the Netherlands with Capillary Electrophoresis

Abstract With the increase of heavy firework abuse more in debt information is required about the chemical compositions of the pyrotechnic charges of these items. In this study CE analysis with indirect UV detection was applied to investigate the possibility to distinguish between batches of flash bangers based upon the composition of the inorganic pyrotechnic charge. With a rapid extraction procedure followed by CE analysis it was possible to differentiate between black powder, flash powder and fake flash powder within 30 minutes. Analysis of flash powder samples concluded in no significant differences between batches due to a similar composition of the powder. However, CE analysis showed potential for black powder and fake flash powder batch differentiation. The impurities found in these powders provided extra information resulting in the possibility of profiling. However, further analysis is required.

Appearance Cobra 6, outside and inside. At the fuse side a compressed block of black powder is shown, the rest has been filled with flash powder.


29

Student Mariska de Heiden Research carried out at

HIMS

Supervisor Dr. Alina Astefanei Title thesis Surface Acoustic Wave Nebulisation – Mass

Spectrometry for the rapid identification of explosives

Abstract In forensic investigations, there is a need for rapid on-site analysis of explosives. The accurate identification of explosives is a difficult task because of the distinct properties of each explosive. Mass spectrometry (MS) is a very sensitive and selective technique that has the potential to identify a wide variety of explosives by using the appropriate ionisation technique. It is well known that the ionisation of explosives is a difficult task because by nature they contain a lot of intrinsic energy. Hence, extensive fragmentation during ionisation leads to uninformative spectra. To overcome this, ambient methods could be an interesting alternative.

This research proposes the use of a new ambient ionization technique called surface acoustic wave nebulisation (SAWN)-MS for the analysis of several relevant classes of organic explosives and their mixtures. The obtained SAWN-MS spectra in this study are compared to the conventional electrospray ionisation (ESI)-MS for all studied compounds. The SAWN-MS spectra show more identified peaks, are more effective at identifying molecular ion peaks, and show higher signal to noise ratios. The method is rapid and involves low sample amounts. Moreover, the results obtained by analysing mixtures of explosives show that SAWN-MS is capable of distinguishing between the explosives analysed in this study and it is also capable of identifying their degradation products that would be present post-explosion.

Figure 1. (a) SAWN-chip and (b) the

experimental setup.


30

Toxicology

Figure 1. The evaporation of the toxic industrial chemical allyl alcohol from rubber and CARC painted panels.

Figure 2. The percentage of hydrazine transferred from a surface to the skin for 15 minutes contact time and a pressure of 20 g/cm2.

Student Mirjam de Bruin-Hoegée Research carried out at

The Netherlands Organisation for applied scientific research (TNO), Rijswijk, the Netherlands

Supervisor Dr. Marloes Joosen Title thesis Determination of the contact risk of toxic

(industrial) chemicals by Gas Chromatography and Ultra-high Performance Liquid Chromatography tandem Mass Spectrometry

Abstract The continuing threats of military conflicts and terrorism may involve the misuse of Toxic Industrial Chemicals (TICs) and toxic pharmaceutical chemicals. Evaluation of the health hazard from contaminated surfaces is essential for the determination of legal exposure safety limits. Quantification and qualification of a contamination may be necessary in case of forensic investigations after terrorist attacks. The main goal of the present study was to develop a validated method to quantify the contact risk of surfaces contaminated with allyl alcohol, fentanyl, hydrazine and phenyl hydrazine. A rapid method was developed for the detection of allyl alcohol using Gas Chromatography (GC-FID). Ultra-high Performance Liquid Chromatography tandem Mass Spectrometry (UPLC-MS/MS) was used for the detection of fentanyl, hydrazine and phenyl hydrazine. Hydrazine and phenyl hydrazine were derivatized before analysis. The amount of chemical transferred from a panel to the skin was a measure for the contact risk. The data showed that the average transfer to the skin was 5 ± 4% for allyl alcohol, 79 ± 9% for fentanyl, 69 ± 13% for hydrazine and 51 ± 11% for phenyl hydrazine. This study demonstrated that the condition of the skin (either wet or dry) and the agent significantly influenced the transfer. Surprisingly, the variables contact time, pressure, contamination level, surface and contamination dispersion did not significantly influence the transfer.

master forensic science

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