Description

Forensic Science International is an international journal publishing original contributions in the many different scientific disciplines pertaining to the forensic sciences. Such fields include, for example, forensic pathology and histochemistry, chemistry, biochemistry and toxicology (including drugs, alcohol, etc.), biology, (including the identification of hairs and fibres), serology, odontology, psychiatry, questioned documents etc., as well as investigations of value to public health in its broadest sense, and the important marginal area where medicine and the law overlap. Forensic Science International publishes: Original papers Review Articles Letters to the Editor Book Reviews Case ReportsThe journal covers all legal aspects of the general disciplines listed above, as well as specialist topics of forensic interest that are included in, or are related to, these disciplines, e.g.: Biochemical and chemical analyses, and the forensic application of advanced analytical, physical, chemical and instrumental techniques Bitemark evidenceBattered child syndrome Questioned documents Ballistics, projectiles and wounds Fingerprints and identification Tool marks Contact traces Poisoning Breathanalysers Accident investigation and mass disasters

Publisher details

Elsevier

Publications in this journal

• Genetic population studies on 17 Y-STR loci in Pashtun population of Swat Valley, Pakistan

  Authors: M. Ilyas, M.S Shahzad, Z. Rahman, M. Shafeeq, M. Israr, M.S Zar, A. Ali, A. Saman, S.S. Jaferi, T. Husnaina, Niaz M. Achakzai

  Forensic Science International.

• Volatile organic compounds released by blowfly larvae and pupae: new perspectives in forensic entomology

  Authors: Frederickx C., Dekeirsschieter J., Brostaux Y., Wathelet J.-P., Verheggen F., Haubruge E.

  Forensic Science International.

• Application of CdSe nanoparticle suspension for developing latent fingermark on adhesives

  Authors: Yuan Feng Wang, Rui Qin Yang, Yan Ji Wang, Zhi Xia Shi, Jian Jun Liu

  Forensic Science International. 185:96.

  Nanometer-sized fluorescent particles were synthesized in an aqueous solution using TGA (mercaptoacetic acid) as the stabilizer. The prepared solution was characterized by fluorescence spectroscopyNanometer-sized fluorescent particles were synthesized in an aqueous solution using TGA (mercaptoacetic acid) as the stabilizer. The prepared solution was characterized by fluorescence spectroscopy and applied for detection of latent fingermarks on adhesives. The effects of stabilizer, precursor, pH value, the concentration of cadmium ion and shell structure on fluorescence were also discussed. The results indicated that the intensity of fluorescence was remarkably increased and the selectivity was well improved when using CdSe nanoparticles; it produced significantly less background development and better contrast after 15 min developing process.

• Forensic drug intelligence: an important tool in law enforcement.

  Authors: Pierrre Esseiva, Sylvain Ioset, Frédéric Anglada, Laëtitia Gasté, Olivier Ribaux, Pierre Margot, Alain Gallusser, Alex Biedermann, Yves Specht, Edmond Ottinger

  Forensic science international. 167(2-3):247-54.

  Organised criminality is a great concern for national/international security. The demonstration of complex crimes is increasingly dependant on knowledge distributed within law-enforcement agenciesOrganised criminality is a great concern for national/international security. The demonstration of complex crimes is increasingly dependant on knowledge distributed within law-enforcement agencies and scientific disciplines. This separation of knowledge creates difficulties in reconstructing and prosecuting such crimes. Basic interdisciplinary research in drug intelligence combined with crime analysis, forensic intelligence, and traditional law enforcement investigation is leading to important advances in crime investigation support. Laboratory results constitute one highly dependable source of information that is both reliable and testable. Their operational use can support investigation and even provide undetected connections or organisation of structure. The foremost difficulties encountered by drug analysts are not principally of a chemical or analytical nature, but methodologies to extract parameters or features that are deemed to be crucial for handling and contextualising drug profiling data. An organised memory has been developed in order to provide accurate, timely, useful and meaningful information for linking spatially and temporally distinct events on a national and international level (including cross-border phenomena). Literature has already pointed out that forensic case data are amenable for use in an intelligence perspective if data and knowledge of specialised actors are appropriately organised, shared and processed. As a particular form of forensic case data, the authors' research focuses on parameters obtained through the systematic physical and chemical profiling of samples of illicit drugs. The procedure is used to infer and characterise links between samples that originate from the same and different seizures. The discussion will not, however, focus on how samples are actually analysed and compared as substantial literature on this topic already exists. Rather, attention is primarily drawn to an active and close collaboration between magistrates, forensic scientists, law enforcement investigators and crime analysts from different institutions with the aim of generating, using and validating relevant profiling case data as integral part of investigative and crime analysis processes. Original advances are highlighted through experiences from criminal investigations of offences related to the unlawful importation, exportation, supply and possession of illicit drugs.

• Nicephor[e]: a web-based solution for teaching forensic and scientific photography.

  Authors: R Voisard, C Champod, J Furrer, J Curchod, A Vautier, G Massonnet, P Buzzini

  Forensic science international. 167(2-3):196-200.

  Nicephor[e] is a project funded by "Swiss Virtual Campus" and aims at creating a distant or mixed web-based learning system in forensic and scientific photography and microscopy. The practical goalNicephor[e] is a project funded by "Swiss Virtual Campus" and aims at creating a distant or mixed web-based learning system in forensic and scientific photography and microscopy. The practical goal is to organize series of on-line modular courses corresponding to the educational requirements of undergraduate academic programs. Additionally, this program could be used in the context of continuing educational programs. The architecture of the project is designed to guarantee a high level of knowledge in forensic and scientific photographic techniques, and to have an easy content production and the ability to create a number of different courses sharing the same content. The e-learning system Nicephor[e] consists of three different parts. The first one is a repository of learning objects that gathers all theoretical subject matter of the project such as texts, animations, images, and films. This repository is a web content management system (Typo3) that permits creating, publishing, and administrating dynamic content via a web browser as well as storing it into a database. The flexibility of the system's architecture allows for an easy updating of the content to follow the development of photographic technology. The instructor of a course can decide which modular contents need to be included in the course, and in which order they will be accessed by students. All the modular courses are developed in a learning management system (WebCT or Moodle) that can deal with complex learning scenarios, content distribution, students, tests, and interaction with instructor. Each course has its own learning scenario based on the goals of the course and the student's profile. The content of each course is taken from the content management system. It is then structured in the learning management system according to the pedagogical goals defined by the instructor. The modular courses are created in a highly interactive setting and offer autoevaluating tests to the students. The last part of the system is a digital assets management system (Extensis Portfolio). The practical portion of each course is to produce images of different marks or objects. The collection of all this material produced, indexed by the students and corrected by the instructor is essential to the development of a knowledge base of photographic techniques applied to a specific forensic subject. It represents also an extensible collection of different marks from known sources obtained under various conditions. It allows to reuse these images for creating image-based case files.

• Morphologic, experimental-comparative investigation as an identification of the injuring instrument method.

  Authors: R Sitiene, A Zakaras, A Pauliukevicius, G Kisielius

  Forensic science international. 167(2-3):255-60.

  Aiming to identify the injuring tool characteristics and the tool itself morphologic, experimental-comparative investigations of the skin wound, rib and cartilage injuries taken during the autopsyAiming to identify the injuring tool characteristics and the tool itself morphologic, experimental-comparative investigations of the skin wound, rib and cartilage injuries taken during the autopsy are performed. During 1995-2004, 489 investigations were performed for this purpose. In 418 cases, knives were submitted for identification of the specific injuring tool (in total-835 knives). In 205 cases the investigation included not only skin wounds, but also the injured rib cartilages. Identification investigations were performed by investigating both the skin wounds morphologic characteristics and dynamic traces-trails in the rib cartilage tissue left by the micro relief of the knife blade edge. In the case of the investigated and experimental skin wounds characteristics coincidence the experimental and comparative dynamic traces investigation was performed when the traces were suitable for the tool identification purposes. In the case of the investigated and experimental skin wounds, dynamic traces coincidence, the totality of the coincided characteristics was considered individual. In those cases, the conclusion included the fact that the injury had been made by a particular knife. According to our data during 1995-2004 in 23 cases-15.9% (5.5% out of the total investigated cases), the knife identification was based on the skin wound characteristics and dynamic traces in the rib cartilage tissue. In our opinion, the dynamic traces in the rib cartilage tissue investigations supplement the identification field and are valuable in the tool identification. In 11 (2.6% out of the total investigated cases) cases knives were identified only by the skin wounds morphologic characteristics, the ribs being not injured or dynamic traces being not suitable for the tool identification.

• Cocaine profiling for strategic intelligence purposes, a cross-border project between France and Switzerland. Part I. Optimisation and harmonisation of the profiling method.

  Authors: S Lociciro, P Hayoz, P Esseiva, L Dujourdy, F Besacier, P Margot

  Forensic science international. 167(2-3):220-8.

  Optimisation and harmonisation of analytical and statistical methodology have been carried out between two forensic laboratories (Lausanne, CH and Lyon, F) in order to provide drug intelligence forOptimisation and harmonisation of analytical and statistical methodology have been carried out between two forensic laboratories (Lausanne, CH and Lyon, F) in order to provide drug intelligence for cross-border cocaine seizures. The aim was to improve the gas chromatographic analysis of cocaine samples for profiling. Some important validation parameters were tested to verify the developed method and demonstrate its profiling capacity: the selectivity of the method with retention time reproducibility, the choice of a derivatisation agent improving the chromatography (MSTFA, BSA, TMSI and BSTFA+TMCS 1%), the cutting agents influence (matrix effect), the influence of the sample storage conditions and the sample quantity to weigh for analyses. Eight main alkaloids, which represent the sample signature, have been selected: ecgonine methyl ester, ecgonine, tropacocaine, benzoylecgonine, norcocaine, cis- and trans-cinnamoylcocaine and 3,4,5-trimethoxycocaine. Their stability in the solvent used (CHCl(3)/pyridine) was demonstrated. In order to reach the final objective, which is the comparison of samples seized and analyzed in two different laboratories, the harmonisation of the profiling method between the two laboratories had to be ensured and is the subject of ongoing research.

• The current status of forensic science laboratory accreditation in Europe.

  Authors: Ekrem Malkoc, Wim Neuteboom

  Forensic science international. 167(2-3):121-6.

  Forensic science is gaining some solid ground in the area of effective crime prevention, especially in the areas where more sophisticated use of available technology is prevalent. All it takes isForensic science is gaining some solid ground in the area of effective crime prevention, especially in the areas where more sophisticated use of available technology is prevalent. All it takes is high-level cooperation among nations that can help them deal with criminality that adopts a cross-border nature more and more. It is apparent that cooperation will not be enough on its own and this development will require a network of qualified forensic laboratories spread over Europe. It is argued in this paper that forensic science laboratories play an important role in the fight against crime. Another, complimentary argument is that forensic science laboratories need to be better involved in the fight against crime. For this to be achieved, a good level of cooperation should be established and maintained. It is also noted that harmonization is required for such cooperation and seeking accreditation according to an internationally acceptable standard, such as ISO/IEC 17025, will eventually bring harmonization as an end result. Because, ISO/IEC 17025 as an international standard, has been a tool that helps forensic science laboratories in the current trend towards accreditation that can be observed not only in Europe, but also in the rest of the world of forensic science. In the introduction part, ISO/IEC 17025 states that "the acceptance of testing and calibration results between countries should be facilitated if laboratories comply with this international standard and if they obtain accreditation from bodies which have entered into mutual recognition agreements with equivalent bodies in other countries using this international standard." Furthermore, it is emphasized that the use of this international standard will assist in the harmonization of standards and procedures. The background of forensic science cooperation in Europe will be explained by using an existing European forensic science network, i.e. ENFSI, in order to understand the current status of forensic science in Europe better. The Council of Europe and the European Union approaches to forensic science will also be discussed by looking at the legal instruments and documents published by these two European organizations. Data collected from 52 European forensic science laboratories will be examined and findings will be evaluated from a quality assurance and accreditation point of view. The need for harmonization and accreditation in forensic science will be emphasized. The steps that should be taken at the European level for increasing and strengthening the role of European forensic science laboratories in the fight against crime will be given as recommendations in the conclusion.

• How do forensic scientists learn to become competent in casework reporting in practice: a theoretical and empirical approach.

  Authors: Stephen Doak, Dimitris Assimakopoulos

  Forensic science international. 167(2-3):201-6.

  In their day-to-day work, carrying out complex tasks, forensic scientists use a combination of explicit, codified standard operating procedures and tacit knowledge developed through their ongoingIn their day-to-day work, carrying out complex tasks, forensic scientists use a combination of explicit, codified standard operating procedures and tacit knowledge developed through their ongoing practice. We show that tacit knowledge is an integral part of the activities of expert forensic science practitioners who continually add to their knowledge repertoire by engaging other scientists through communities of practice. We wish to shed fresh light on the gaining of tacit knowledge by forensic scientists during their apprentice formative years, termed as legitimate peripheral participation. In quantifying tacit knowledge exchanges, we use social network analysis, a methodology for the analysis of social structures, to map relational knowledge flows between forensic scientists within communities of practice at the Forensic Science Laboratory, Ireland. This paper sheds light on the importance of tacit knowledge within the training regime of forensic scientists and its recognition as equal to the part played by explicit knowledge.

• ENFSI collaborative testing programme for ignitable liquid analysis: a review.

  Authors: Jeanet Hendrikse

  Forensic science international. 167(2-3):213-9.

  The Fire and Explosion Investigation Working Group of the European Network of Forensic Science Institutes (ENFSI) is the organiser of a collaborative testing programme for ignitable liquid analysis.The Fire and Explosion Investigation Working Group of the European Network of Forensic Science Institutes (ENFSI) is the organiser of a collaborative testing programme for ignitable liquid analysis. The testing programme was initiated in 1998. Initially to inventory the analytical methods used in this field of analysis, but with the ultimate goal to establish a European testing programme for fire debris analysts. As of today, five tests have been conducted. This article will provide an overview of the first five ENFSI collaborative tests for ignitable liquid analysis. The background, objectives and characteristics of the testing programme are summarised, followed by an overview of the sample composition employed, the participants' performance, the difficulties and the lessons learned in each test.

• Non-destructive testing techniques for the forensic engineering investigation of reinforced concrete buildings.

  Authors: Brian Hobbs, Mohamed Tchoketch Kebir

  Forensic science international. 167(2-3):167-72.

  This study describes in detail the results of a laboratory investigation where the compressive strength of 150mm side-length cubes was evaluated. Non-destructive testing (NDT) was carried out usingThis study describes in detail the results of a laboratory investigation where the compressive strength of 150mm side-length cubes was evaluated. Non-destructive testing (NDT) was carried out using ultrasonic pulse velocity (UPV) and impact rebound hammer (IRH) techniques to establish a correlation with the compressive strengths of compression tests. To adapt the Schmidt hammer apparatus and the ultrasonic pulse velocity tester to the type of concrete used in Algeria, concrete mix proportions that are recommended by the Algerian code were chosen. The resulting correlation curve for each test is obtained by changing the level of compaction, water/cement ratio and concrete age of specimens. Unlike other works, the research highlights the significant effect of formwork material on surface hardness of concrete where two different mould materials for specimens were used (plastic and wood). A combined method for the above two tests, reveals an improvement in the strength estimation of concrete. The latter shows more improvement by including the concrete density. The resulting calibration curves for strength estimation were compared with others from previous published literature.

• Clothing damage analysis in alleged sexual assaults--the need for a systematic approach.

  Authors: C A Boland, S D McDermott, J Ryan

  Forensic science international. 167(2-3):110-5.

  Clothing damage analysis is an integral part of the examinations carried out in sexual assault type cases. This analysis can be used to corroborate different versions of events and is at its mostClothing damage analysis is an integral part of the examinations carried out in sexual assault type cases. This analysis can be used to corroborate different versions of events and is at its most powerful in elucidating false allegation cases and consent cases. The purpose of this study was to determine to what extent people with varying levels of forensic awareness, experience and training could correctly carry out damage analysis. Two participant groups were asked to take part in this study. Group A ('forensic group') comprised participants at a forensic science conference, and Group B ('student group') comprised students undertaking a degree course in Forensic Science. Each group was given a practical workshop consisting of a lecture outlining common fabric types and general features observed in different damage types. Each participant was subsequently shown 25 pieces of 'damage' and asked to identify both the type of fabric construction (knit or weave) and the type of damage (cut, tear, rip, wear and tear). The ability to identify fabric construction and damage types varied within the two groups studied and across the groups. The forensic group performed better both in fabric and damage assessment than the student group. This paper suggests a systematic approach to clothing damage analysis to maximise the benefits that can be obtained from this area of forensic science and to minimise the subjectivity within the field.

• Influence of rubber compound and tread pattern of retreaded tyres on vehicle active safety.

  Authors: Jakub Zebala, Piotr Ciepka, Adam Reza, Robert Janczur

  Forensic science international. 167(2-3):173-80.

  The aim of the article is to present the results of road tests of original and retreaded tyres, analysed in the aspect of vehicle active safety. The tests covered emergency braking, steady-stateThe aim of the article is to present the results of road tests of original and retreaded tyres, analysed in the aspect of vehicle active safety. The tests covered emergency braking, steady-state circular tests and severe lane-change manoeuvre. The tests were performed in summer and winter conditions. Original Michelin tyres and Michelin tyres retreaded with summer and winter rubber compounds were used. The results of the tests proved that vehicle active safety is affected by retreaded tyres. The differences between braking deceleration of a car with original tyres and braking deceleration of a car with retreaded tyres confirmed the necessity of performing braking tests on the place of accident with the set of tyres with which the vehicle participating in the accident was equipped.

• Multimodal biometrics for identity documents (MBioID).

  Authors: Damien Dessimoz, Jonas Richiardi, Christophe Champod, Andrzej Drygajlo

  Forensic science international. 167(2-3):154-9.

  The MBioID initiative has been set up to address the following germane question: What and how biometric technologies could be deployed in identity documents in the foreseeable future? This researchThe MBioID initiative has been set up to address the following germane question: What and how biometric technologies could be deployed in identity documents in the foreseeable future? This research effort proposes to look at current and future practices and systems of establishing and using biometric identity documents (IDs) and evaluate their effectiveness in large-scale developments. The first objective of the MBioID project is to present a review document establishing the current state-of-the-art related to the use of multimodal biometrics in an IDs application. This research report gives the main definitions, properties and the framework of use related to biometrics, an overview of the main standards developed in the biometric industry and standardisation organisations to ensure interoperability, as well as some of the legal framework and the issues associated to biometrics such as privacy and personal data protection. The state-of-the-art in terms of technological development is also summarised for a range of single biometric modalities (2D and 3D face, fingerprint, iris, on-line signature and speech), chosen according to ICAO recommendations and availabilities, and for various multimodal approaches. This paper gives a summary of the main elements of that report. The second objective of the MBioID project is to propose relevant acquisition and evaluation protocols for a large-scale deployment of biometric IDs. Combined with the protocols, a multimodal database will be acquired in a realistic way, in order to be as close as possible to a real biometric IDs deployment. In this paper, the issues and solutions related to the acquisition setup are briefly presented.

• Latent fingermark visualisation using a scanning Kelvin probe.

  Authors: Geraint Williams, Neil McMurray

  Forensic science international. 167(2-3):102-9.

  The current state of the art in fingermark visualisation on metallic surfaces by a scanning Kelvin probe (SKP) technique is described. Latent eccrine fingermarks deposited on a range of polished andThe current state of the art in fingermark visualisation on metallic surfaces by a scanning Kelvin probe (SKP) technique is described. Latent eccrine fingermarks deposited on a range of polished and roughened metallic surfaces can be effectively imaged. Results are presented which show that the SKP technique is able to visualise fingermarks obscured beneath optically opaque soot films and retrieve ridge detail in instances where fingermarks have been physically removed (e.g. by rubbing with a tissue) from a metal surface. SKP Volta potential mapping of small, severely non-planar metal objects such as fired brass cartridge cases is demonstrated.

• Evidence evaluation in fingerprint comparison and automated fingerprint identification systems--modelling within finger variability.

  Authors: Nicole M Egli, Christophe Champod, Pierre Margot

  Forensic science international. 167(2-3):189-95.

  Recent challenges and errors in fingerprint identification have highlighted the need for assessing the information content of a papillary pattern in a systematic way. In particular, estimation of theRecent challenges and errors in fingerprint identification have highlighted the need for assessing the information content of a papillary pattern in a systematic way. In particular, estimation of the statistical uncertainty associated with this type of evidence is more and more called upon. The approach used in the present study is based on the assessment of likelihood ratios (LRs). This evaluative tool weighs the likelihood of evidence given two mutually exclusive hypotheses. The computation of likelihood ratios on a database of marks of known sources (matching the unknown and non-matching the unknown mark) allows an estimation of the evidential contribution of fingerprint evidence. LRs are computed taking advantage of the scores obtained from an automated fingerprint identification system and hence are based exclusively on level II features (minutiae). The AFIS system attributes a score to any comparison (fingerprint to fingerprint, mark to mark and mark to fingerprint), used here as a proximity measure between the respective arrangements of minutiae. The numerator of the LR addresses the within finger variability and is obtained by comparing the same configurations of minutiae coming from the same source. Only comparisons where the same minutiae are visible both on the mark and on the print are therefore taken into account. The denominator of the LR is obtained by cross-comparison with a database of prints originating from non-matching sources. The estimation of the numerator of the LR is much more complex in terms of specific data requirements than the estimation of the denominator of the LR (that requires only a large database of prints from an non-associated population). Hence this paper addresses specific issues associated with the numerator or within finger variability. This study aims at answering the following questions: (1) how a database for modelling within finger variability should be acquired; (2) whether or not the visualisation technique or the choice of different minutiae arrangements may influence that modelling and (3) what is the magnitude of LRs that can be expected from such a model. Results show that within finger variability is affected by the visualisation technique used on the mark, the number of minutiae and the minutiae configuration. They also show that the rates of misleading evidence in the likelihood ratios obtained for one of the configurations examined are low.

• Sugar and fatty acid analysis in ecstasy tablets.

  Authors: Ines Baer, Pierre Margot

  Forensic science international. 167(2-3):229-33.

  Sugars and stearates (composed of fatty acids) are both frequent components used in the production of ecstasy tablets. Their analysis can therefore provide supplementary information useful for drugSugars and stearates (composed of fatty acids) are both frequent components used in the production of ecstasy tablets. Their analysis can therefore provide supplementary information useful for drug intelligence. Links established using these substances would be very significant as they should give us information about the manufacturer of the tablets. Two methods have been developed for the analysis of sugars and fatty acids by GC-MS and were applied to 109 ecstasy tablets. Characterisation of the samples should allow the differentiation of a certain number of them and furthermore their classification into groups. This is obtained by analysing the raw data using chemometric methods. Several pre-treatments have been tested together with six similarity measures on a small number of ecstasy samples in order to determine which combination would best characterise one ecstasy sample and differentiate it from the others at the same time. Normalisation followed by the fourth square and applied together with the squared cosine function appeared to give the best results and has been applied to all samples. The correlation values obtained of each sample with all others express the probability of a presence of a link between two samples. In order to verify the signification of these values, and thus of a link, all samples have been compared considering the data visually according to three selected criterions. The 109 examined samples could be divided into 67 groups, with 43 of them containing only one sample. Considering the distribution of their correlation values, sample pairs showing a value below 0.23 can be considered as linked. As the excipients are necessarily related to the blending, which also includes the active substance, and variation in the excipient content has been proven by the grouping of the samples, a low similarity value does indicate a link with regard to the producer. In conclusion, it appears that the result obtained with the excipients is certainly very valuable, but all other available information has to be taken into account as well before making any conclusions.

• The difference between drug money and a "lifetime's savings".

  Authors: Karl A Ebejer, Jane Winn, James F Carter, Richard Sleeman, Jill Parker, Fritjof Körber

  Forensic science international. 167(2-3):94-101.

  In many countries, monies suspected of being associated with drug trafficking can be seized by the authorities. One of the ways of investigating this association is through the analysis of seizedIn many countries, monies suspected of being associated with drug trafficking can be seized by the authorities. One of the ways of investigating this association is through the analysis of seized banknotes for traces of controlled drugs. We report three studies which may assist the expert in assessing whether banknotes contaminated with diamorphine are part of the general population of notes in circulation or whether they show unusual contamination patterns which require explanation. Study 1 is based on three plausible contamination scenarios as they may occur during the various stages of an illicit drug transaction and seizure. It shows that notes which have been in direct contact with visible traces of diamorphine show significantly higher contamination to those in more indirect contact with the drug. Study 2 investigates the transfer of diamorphine from one highly contaminated note to other notes in a bundle over a period of 10 weeks with and without agitation. It was found that the total amount of drug transferred was smaller than 6% and no more than 4 out of a bundle of 10 previously clean notes became lightly contaminated. Based on extensive background data, study 3 proposes a probabilistic model to assess whether an observed proportion of diamorphine bearing banknotes is likely to have been contaminated by chance. The model predicts that there is only a 0.3% chance that a bundle of 100 notes from the general banknote population contains more than six contaminated specimens. Jointly, the three studies give useful indications for the spread of contamination throughout a sample and the amounts of heroin which may be expected given plausible contamination scenarios.

• Max Frei theory revisitation: does really strokes depth change along time?

  Authors: Giuseppe Schirripa Spagnolo, Davide Zavattaro, Michele De Santis, Luca Gennaro Ferrillo

  Forensic science international. 167(2-3):163-6.

  A serious problem in questioned document examination is to establish the age of written lines. With respect to paper dating, in the past, Max Frei theory (based only on microscope analysis) claimedA serious problem in questioned document examination is to establish the age of written lines. With respect to paper dating, in the past, Max Frei theory (based only on microscope analysis) claimed that strokes are time-dependent. Therefore, according to this theory, it has been asserted that from the analysis of the strokes depth changes it is possible to try to date the handwritten document (to find out that the document is older than ...). In the present work, we investigate the strokes depth change by a laser profilometer considering not only the time but also microclimatic variations. First, we analyze the stability of stroke characteristics along the time. In particular, we demonstrate that if the document is preserved without change of temperature and humidity, the depth of the strokes has not appreciable changes. In this way, we have the purpose to verify the real possibility of documents dating by means of Max Frei theory. Subsequently, we test how the 3D profile of strokes changes in connection with the microclimatic variations. In particular, we test humidity variations. With this experiment, we show that humidity variations reduce the strokes depth. Moreover, this effect shows a non-linear trend, leaving a hysteresis on the depth. Finally, we show that the analysis of 3D stroke profile is unable to determine the age of documents.

• Applications of ENF criterion in forensic audio, video, computer and telecommunication analysis.

  Authors: Catalin Grigoras

  Forensic science international. 167(2-3):136-45.

  This article reports on the electric network frequency criterion as a means of assessing the integrity of digital audio/video evidence and forensic IT and telecommunication analysis. A briefThis article reports on the electric network frequency criterion as a means of assessing the integrity of digital audio/video evidence and forensic IT and telecommunication analysis. A brief description is given to different ENF types and phenomena that determine ENF variations. In most situations, to reach a non-authenticity opinion, the visual inspection of spectrograms and comparison with an ENF database are enough. A more detailed investigation, in the time domain, requires short time windows measurements and analyses. The stability of the ENF over geographical distances has been established by comparison of synchronized recordings made at different locations on the same network. Real cases are presented, in which the ENF criterion was used to investigate audio and video files created with secret surveillance systems, a digitized audio/video recording and a TV broadcasted reportage. By applying the ENF Criterion in forensic audio/video analysis, one can determine whether and where a digital recording has been edited, establish whether it was made at the time claimed, and identify the time and date of the registering operation.

• Pattern detection in forensic case data using graph theory: application to heroin cutting agents.

  Authors: Anne-Laure Terrettaz-Zufferey, Frédéric Ratle, Olivier Ribaux, Pierre Esseiva, Mikhail Kanevski

  Forensic science international. 167(2-3):242-6.

  Pattern recognition techniques can be very useful in forensic sciences to point out to relevant sets of events and potentially encourage an intelligence-led style of policing. In this study, thesePattern recognition techniques can be very useful in forensic sciences to point out to relevant sets of events and potentially encourage an intelligence-led style of policing. In this study, these techniques have been applied to categorical data corresponding to cutting agents found in heroin seizures. An application of graph theoretic methods has been performed, in order to highlight the possible relationships between the location of seizures and co-occurrences of particular heroin cutting agents. An analysis of the co-occurrences to establish several main combinations has been done. Results illustrate the practical potential of mathematical models in forensic data analysis.

• Superimposition and projective transformation of 3D object.

  Authors: Hana Eliásová, Pavel Krsek

  Forensic science international. 167(2-3):146-53.

  Superimposition is an efficient method for evaluation of coincidence between a skull and a photo portrait. The principle of superimposition method lies in the projection of the skull into the faceSuperimposition is an efficient method for evaluation of coincidence between a skull and a photo portrait. The principle of superimposition method lies in the projection of the skull into the face image. During the projection of an object with a perspective camera, the mapping of a three-dimensional object into a two-dimensional image takes place. The acquired images of the same object are more or less distorted due to various photographic conditions, due to extrinsic and intrinsic parameters of the camera. The distortions have important influence onto reliability of human identification by the superimposition method. Mathematically we can describe most of the distortions. On the basis of the description the divergences could be simulated and in some cases eliminated by geometric transformation of the compared images. We are presenting a mathematical model of the standard projective camera and the mathematical description of distortions which are important for the superimposition process. The results show the distortions and the elimination of the distortions by means of the projection model.

• Application of computational fluid dynamics modelling in the process of forensic fire investigation: problems and solutions.

  Authors: O Delémont, J-C Martin

  Forensic science international. 167(2-3):127-35.

  Fire modelling has been gaining more and more interest into the community of forensic fire investigation. Despite an attractiveness that is partially justified, the application of fire models in thatFire modelling has been gaining more and more interest into the community of forensic fire investigation. Despite an attractiveness that is partially justified, the application of fire models in that field of investigation rises some difficulties. Therefore, the understanding of the basic principles of the two main categories of fire models, the knowledge of their effective potential and their limitations are crucial for a valid and reliable application in forensic science. The present article gives an overview of the principle and basics that characterise the two kinds of fire models: zone models and field models. Whereas the first ones are developed on the basis of mathematical relation from empirical observations, such as stratification of fluid zones, and give a relatively broad view of mass and energy exchanges in an enclosure, the latter are based on fundamentals of fluid mechanics and represent the application of Computational Fluid Dynamics (CFD) to fire scenarii. Consequently, the data that are obtained from these two categories of fire models differ in nature, quality and quantity. First used in a fire safety perspective, fire models are not easily applied to assess parts of forensic fire investigation. A suggestion is proposed for the role of fire modelling in this domain of competence: a new tool for the evaluation of alternative hypotheses of origin and cause by considering the dynamic development of the fire. An example of a real case where such an approach was followed is explained and the evaluation of the obtained results comparing to traces revealed during the on-site investigation is enlightened.

• The potential (negative) influence of observational biases at the analysis stage of fingermark individualisation.

  Authors: Beatrice Schiffer, Christophe Champod

  Forensic science international. 167(2-3):116-20.

  Recent cases of erroneous identification have strengthened critical comments on the reliability of fingerprint identification. This goes hand in hand with recent publications regarding the lack ofRecent cases of erroneous identification have strengthened critical comments on the reliability of fingerprint identification. This goes hand in hand with recent publications regarding the lack of scientific foundation of the discipline. Combined with "legislative" needs, such as for instance the admissibility criteria under Daubert, or experimental studies revealing potential bias, the call for research on the identification process has become more urgent. That background set the basis of this research project financed by the Swiss National Science Foundation (SNSF) which includes, among other parts, experimental tests to study potential observational biases in the analysis stage of fingerprint individualisation. These tests have been submitted to several groups of forensic science students at the University of Lausanne. The aim is to study factors potentially influencing the analysis of fingermarks, more specifically the influence of training/education (test I) as well as the potential impact of case contextual information or known print availability (test II). For all tests students were given 11 or 12 fingermarks of a medium to difficult quality, with a range of 8-15 minutiae. For all tests the task was always the same for the participants but carried out in different contexts: to analyse the marks, to annotate the minutiae observed, to designate them and to decide on the status of the mark in two categories, exploitable and identifiable. The aim was to see how the fingermarks were annotated by different individuals so as to have an idea of the variation in annotation and counting in the analysis stage only. For test I, students were submitted the same 12 fingerprints before and after having followed specific training in fingermark individualisation. The aim was to see how training/education impacts the analysis of fingermarks. For test II, were participants given eleven fingermarks so as to study whether the presence of a comparison print changes the amount of minutiae found and whether low/high-profile background information influences the analysis stage. Results show that for test I the effect of training can be observed, among other, in an increase of minutiae annotated and a higher consensus between participants. For test II no effect of the stimuli used to induce observational biases has been observed by all of the factors studied.

• NIR analysis of cellulose and lactose--application to ecstasy tablet analysis.

  Authors: Ines Baer, Robert Gurny, Pierre Margot

  Forensic science international. 167(2-3):234-41.

  Cellulose and lactose are the most frequently used excipients in illicit ecstasy production. The aim of this project was to use near infrared reflectance spectroscopy (NIRS) for the determination ofCellulose and lactose are the most frequently used excipients in illicit ecstasy production. The aim of this project was to use near infrared reflectance spectroscopy (NIRS) for the determination of the different chemical forms of these two substances, as well as for the differentiation of their origin (producer). It was possible to distinguish between the different chemical forms of both compounds, as well as between their origins (producers), although within limits. Furthermore, the possibilities to apply NIR for the analysis of substances such as found in illicit tablets were studied. First, a few cellulose and lactose samples were chosen to make mixtures with amphetamine at three degrees of purity (5, 10 and 15%), in order to study the resulting changes in the spectra as well as to simultaneously quantify amphetamine and identify the excipient. A PLS2 model could be build to predict concentrations and excipient. Secondarily, the technique was to be applied to real ecstasy tablets. About 40 ecstasy seizures were analysed with the aim to determine the excipient and to check them against each other. Identification of the excipients was not always obvious, especially when more than one excipient were present. However, a comparison between tablets appeared to give groups of similar samples. NIR analysis results in spectra representing the tablet blend as a whole taking into account all absorbing compounds. Although NIRS seems to be an appropriate method for ecstasy profiling, little is known about intra- and intervariability of compression batches.

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