Bhoelai B.,Netherlands Forensic Institute NFI |
de Jong B.,Netherlands Forensic Institute NFI |
Sijen T.,Netherlands Forensic Institute NFI
Forensic Science International: Genetics Supplement Series | Year: 2013
The presence of contact traces on objects can be caused by different activities such as personal use, firm gripping or casual touching. As these activities are of distinct duration and intensity, we hypothesised that cell material corresponding to different epidermal depth may be deposited. Epidermal layers have distinguishable biomarker profiles [1,2] that are formed by cell proliferation, cell differentiation and cell death. Thus, we examined whether mRNAs corresponding to different epidermal layers can distinguish the different types of contact. From an initial set of 14 candidates, six epidermal markers showed sufficient expression in contact traces to be included in an mRNA multiplex assay that carried body fluid markers as well . Using a set of 30 user and 30 grip traces left by identical donors on identical substrates, we determined that none of these epidermal mRNAs could specify contact type. When the corresponding DNA data were included in the analyses no relation with contact type could be established either. © 2013 Elsevier Ireland Ltd.
Bailey J.A.,Minnesota State University, Mankato |
Wang Y.,University of North Carolina at Wilmington |
van de Goot F.R.W.,VU University Amsterdam |
Gerretsen R.R.R.,Netherlands Forensic Institute NFI |
Gerretsen R.R.R.,Leiden University
Forensic Science, Medicine, and Pathology | Year: 2011
Saw marks on bone have been routinely reported in dismemberment cases. When saw blade teeth contact bone and the bone is not completely sawed into two parts, bone fragments are removed forming a channel or kerf. Therefore, kerf width can approximate the thickness of the saw blade. The purpose of this study is to evaluate 100 saw kerf widths in bone produced by ten saw types to determine if a saw can be eliminated based on the kerf width. Five measurements were taken from each of the 100 saw kerfs to establish an average thickness for each kerf mark. Ten cuts were made on 10 sections of bovine bone, five with human-powered saws and five with mechanical-powered saws. The cuts were examined with a stereoscopic microscope utilizing digital camera measuring software. Two statistical cumulative logistic regression models were used to analyze the saw kerf data collected. In order to estimate the prediction error, repeated stratified cross-validation was applied in analyzing the kerf mark data. Based on the two statistical models used, 70-90% of the saws could be eliminated based on kerf width. © 2010 The Author(s).
Van Den Bos J.,Netherlands Forensic Institute NFI
2014 Software Evolution Week - IEEE Conference on Software Maintenance, Reengineering, and Reverse Engineering, CSMR-WCRE 2014 - Proceedings | Year: 2014
Binary file formats are regularly extended and modified, often unintentionally in the form of bugs in the implementations of applications and libraries that create files. Applications that need to read data from binary files created by other applications face the complicated task of supporting the resulting many variants. Lightweight implementation patterns to perform runtime reverse engineering can be used to handle common extensions, modifications and bugs. This increases application usability by generating fewer errors as well as provides useful automated feedback to maintainers. This paper describes a set of patterns that are the result of experience in developing and maintaining a collection of automated digital forensics tools. The patterns are illustrated through practical examples and can be directly applied by practitioners. © 2014 IEEE.
Berger C.E.H.,Netherlands Forensic Institute NFI |
Buckleton J.,Environmental Science and Research |
Champod C.,University of Lausanne |
Evett I.W.,London Laboratory |
Jackson G.,University of Abertay Dundee
Science and Justice | Year: 2011
This is a discussion of a number of issues that arise from the recent judgment in R v T . Although the judgment concerned with footwear evidence, more general remarks have implications for all disciplines within forensic science. Our concern is that the judgment will be interpreted as being in opposition to the principles of logical interpretation of evidence. We re-iterate those principles and then discuss several extracts from the judgment that may be potentially harmful to the future of forensic science. A position statement with regard to evidence evaluation, signed by many forensic scientists, statisticians and lawyers, has appeared in this journal  and the present paper expands on the points made in that statement. © 2011 Forensic Science Society.
Rijnders M.R.,Netherlands Forensic Institute NFI |
Stamouli A.,Netherlands Forensic Institute NFI |
Bolck A.,Netherlands Forensic Institute NFI
Journal of Forensic Sciences | Year: 2010
Variations in gunshot residue (GSR) compositions are used in the reconstruction of shooting incidents. In this study, GSR samples taken from seven different locations around and in the firearm were collected and analyzed using scanning electron microscopy/energy dispersive X-ray analysis. Four different types of ammunition were applied. Very low correlations were found when different ammunition were used. This clearly shows that it is possible to differentiate between ammunition types. When the same ammunition was used, high correlations were found between samples taken from external positions (such as hands of shooter, bullet-entrance holes) but poor correlation was found between internal samples (such as firearm barrel, cartridge case) and external samples. A high degree of association was found between samples that simulated victim and shooter. These findings clearly demonstrate that GSR comparison studies are meaningful but care needs to be taken when choosing suitable exhibits. External samples (such as hands of shooter, bullet-entrance holes) are more suitable candidates than internal samples (barrel of the firearm, cartridge case). © 2010 American Academy of Forensic Sciences.
Verheij S.,Netherlands Forensic Institute NFI |
Clarisse L.,Netherlands Forensic Institute NFI |
van den Berge M.,Netherlands Forensic Institute NFI |
Sijen T.,Netherlands Forensic Institute NFI
Forensic Science International: Genetics Supplement Series | Year: 2013
DNA analysis systems suited for rapid, mobile, and non-expert operation are emerging in forensics. We show that the first version of the IntegenX RapidHIT™ 200 Human DNA Identification System enables reliable, correct and fast DNA profiling when buccal swabs are used, which is in agreement with the designed functionality. Genotyping information was also obtained for saliva, semen, skin and hair specimens, but not from blood. Standard DNA procedures were much more sensitive than this first RapidHIT release, but promise lies in the finding that mock casework samples show informative profiling results, also when the system is placed in a mobile vehicle. © 2013 Elsevier Ireland Ltd.
Muramoto S.,U.S. National Institute of Standards and Technology |
Forbes T.P.,U.S. National Institute of Standards and Technology |
Van Asten A.C.,Netherlands Forensic Institute NFI |
Van Asten A.C.,University of Amsterdam |
Gillen G.,U.S. National Institute of Standards and Technology
Analytical Chemistry | Year: 2015
A novel test sample for the spatially resolved quantification of illicit drugs on the surface of a fingerprint using time-of-flight secondary ion mass spectrometry (ToF-SIMS) and desorption electrospray ionization mass spectrometry (DESI-MS) was demonstrated. Calibration curves relating the signal intensity to the amount of drug deposited on the surface were generated from inkjet-printed arrays of cocaine, methamphetamine, and heroin with a deposited-mass ranging nominally from 10 pg to 50 ng per spot. These curves were used to construct concentration maps that visualized the spatial distribution of the drugs on top of a fingerprint, as well as being able to quantify the amount of drugs in a given area within the map. For the drugs on the fingerprint on silicon, ToF-SIMS showed great success, as it was able to generate concentration maps of all three drugs. On the fingerprint on paper, only the concentration map of cocaine could be constructed using ToF-SIMS and DESI-MS, as the signals of methamphetamine and heroin were completely suppressed by matrix and substrate effects. Spatially resolved quantification of illicit drugs using imaging mass spectrometry is possible, but the choice of substrates could significantly affect the results. © 2015 American Chemical Society.
Slooten K.,Netherlands Forensic Institute NFI |
Slooten K.,VU University Amsterdam
Forensic Science International: Genetics | Year: 2016
While likelihood ratio calculations were until the recent past limited to the evaluation of mixtures in which all alleles of all donors are present in the DNA mixture profile, more recent methods are able to deal with allelic dropout and drop-in. This opens up the possibility to obtain likelihood ratios for mixtures where this was not previously possible, but it also means that a full match between the alleged contributor and the crime stain is no longer necessary. We investigate in this article what the consequences are for relatives of the actual donors, because they typically share more alleles with the true donor than an unrelated individual. We do this with a semi-continuous binary approach, where the likelihood ratios are based on the observed alleles and the dropout probabilities for each donor, but not on the peak heights themselves. These models are widespread in the forensic community. Since in many cases a simple model is used where a uniform dropout probability is assumed for all (or for all unknown) contributors, we explore the extent to which this alters the false positive probabilities for relatives of donors, compared to what would have been obtained with the correct probabilities of dropout for each donor. © 2015 Elsevier Ireland Ltd. All rights reserved.
Development and validation of highly selective screening and confirmatory methods for the qualitative forensic analysis of organic explosive compounds with high performance liquid chromatography coupled with (photodiode array and) LTQ ion trap/Orbitrap mass spectrometric detections (HPLC-(PDA)-LTQOrbitrap)
Xu X.,Netherlands Forensic Institute NFI |
Koeberg M.,Netherlands Forensic Institute NFI |
Kuijpers C.-J.,Netherlands Forensic Institute NFI |
Kok E.,Netherlands Forensic Institute NFI
Science and Justice | Year: 2014
An LTQ-Orbitrap FTMS is a new (hybrid) mass spectrometric (MS) analyzer. It allows for the acquisition of full scan MSn (n-stage fragmentations, n=1-n) spectra with the linear ion trap detector (LTQ) at high speed and/or with the Fourier Transform-detector (Orbitrap) with ultra high mass resolution (>60,000 at m/z<400amu) and high mass accuracy (≤1ppm with internal calibration). In addition it may be coupled with liquid chromatography (LC) with photo diode array (PDA) detection.Two methods for the forensic screening and confirmation of all common trace explosives in post-blast residues have been developed on this instrument using atmospheric pressure chemical ionization (APCI). In one run, the nitrogen-containing explosives are analyzed with the combination of "LC-(PDA)-APCI(-)-LTQ MS2/Orbitrap FTMS" (Method 1). In another run, peroxide explosives are analyzed with "LC-APCI(+)-LTQ MS2/Orbitrap FTMS" (Method 2).The performance of both methods has been validated according to procedures defined in the EU COMMISSION DECISION implementing Council Directive 96/23/EC concerning the performance of analytical methods and the interpretation of results (DC 2002/657/EC) and other standards (NEN 17025 and NEN 7777). The methods are highly selective due to the simultaneous utilization of the Orbitrap FTMS and LTQ MS2, both of which are highly selective detectors Tested explosive compounds can be detected in the molecular ion form by the Orbitrap analyzer with minimal mass interference in different matrices when using an extremely narrow mass tolerance detection window (≤2ppm). The identification of a detected compound follows an identification point system. Experimental results show that almost all explosive compounds meet the confirmation criteria (minimum 4 points) required for the positive identification by the DC 2002/657/EC. © 2014 Forensic Science Society.
Ricciardi F.,University of Florence |
Slooten K.,Netherlands Forensic Institute NFI
Forensic Science International: Genetics | Year: 2014
In recent years, the use of DNA data for personal identification has become a crucial feature for forensic applications such as disaster victim identification (DVI). Computational methods to cope with these kinds of problems must be designed to handle large scale events with a high number of victims, obtaining likelihood ratios and posterior odds with respect to different identification hypotheses. Trying to minimize identification error rates (i.e., false negatives and false positives), a number of computational methods, based either on the choice between alternative mutation models or on the adoption of a different strategy, are proposed and evaluated. Using simulation of DNA profiles, our goal is to suggest which is the most appropriate way to address likelihood ratio computation in DVI cases, especially to be able to efficiently deal with complicating issues such as mutations or null alleles, considering that data about these latter are limited and fragmentary. © 2014 Elsevier Ireland Ltd.