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CMF-iteMS: An automatic threshold selection for detection of copy-move forgery

Abd Warif NB, Idris MYI, Abdul Wahab AW, Salleh R, Ismail A

Forensic Sci Int, 2019 Feb;295:83-99.
PMID: 30576953 DOI: 10.1016/j.forsciint.2018.12.004

Taking into consideration that the prior CMF detection methods rely on several fixed threshold values in the filtering process, we propose an efficient CMF detection method with an automatic threshold selection, named as CMF-iteMS. The CMF-iteMS recommends a PatchMatch-based CMF detection method that adapts Fourier-Mellin Transform (FMT) as the feature extraction technique while a new automatic threshold selection based on iterative means of regions size (iteMS) procedure is introduced to have flexibility in changing the threshold value for various characteristics (quality, sizes, and attacks) in each input image. To ensure the reliability of the proposed CMF-iteMS, the method is compared with four state-of-the-art CMF detection methods based on Scale Invariant Feature Transform (SIFT), patch matching, multi-scale analysis and symmetry techniques using three available datasets that cover the variety of characteristics in CMF images. The results show that the F-score of the CMF-iteMS outperformed existing CMF detection methods by exceeding an average of 90% F-score values for image-level evaluation and 82% of F-score value for pixel-level evaluation for all datasets in original size. As special attention is given to the image resizing attack, the method is able to maintain the highest performance even if the images in the datasets are resized to 0.25 parameter.
Fulltext Reliability and limitations of permanent tooth staging techniques

Abdul Rahim AH, Davies JA, Liversidge HM

Forensic Sci Int, 2023 May;346:111654.
PMID: 37011430 DOI: 10.1016/j.forsciint.2023.111654

Reliability, or repeatability, of permanent tooth staging techniques is usually expressed as Cohen's Kappa. This single value obscures information about the quantity and allocation of disagreements. In this study we assess and compare intra-observer reliability of permanent tooth staging techniques described by Nolla, Moorrees et al. and Demirjian et al. The sample was panoramic radiographs of healthy dental patients made up of 100 males and 100 females aged 6-15 years. All permanent teeth on the left side (excluding third molars) were scored twice. Weighted Kappa and percentage agreement were calculated. Results show Kappa values for all teeth combined as 0.918, 0.922 and 0.938 for Demirjian (number of teeth N = 2682), Nolla (N = 2698) and Moorrees (N = 2674) respectively. A comparison of Kappa values between upper and lower teeth showed marginally higher values for upper incisors and lower molar for all three scoring methods. Small differences in Kappa values were noted between tooth types with the upper first molar having smaller values than other teeth. Percentage agreement ranged from 81 % (Moorrees), 86 % (Nolla) to 87 % (Demirjian). Tooth stage differences between first and second assessments were not more than one stage. Our findings show that Demirjian scoring is marginally more reliable than Nolla or Moorrees. We suggest that (1) data for reliability are tabulated in full to show the quantity and allocation of disagreement between first and second readings, and (2) that the reliability sample is sufficiently large with a wide age range to include multiple different tooth stages.
An investigation into the suitability of some etching reagents to restoring obliterated stamped numbers on cast iron engine blocks of cars

Abdul Wahab MF, Mohamad Ghani NI, Kuppuswamy R

Forensic Sci Int, 2012 Nov 30;223(1-3):53-63.
PMID: 22955030 DOI: 10.1016/j.forsciint.2012.07.020

Most of the automotive companies use cast iron for their engine blocks. Restoration of obliterated number on these iron surfaces by chemical etching is known to be quite difficult. Heating of the obliterated surface using oxyacetylene flame is an alternative recovery treatment suggested in literature and used in practice. However chemical etching has been established to be the most sensitive technique for detection of metal deformation present under stamped serial numbers. Hence, the current work investigated the suitability of some common etchants on cast iron surfaces with a view to determining the most suitable one for revealing the obliterated marks. The reagents tested were mostly copper containing Fry's reagent and its modifications. Two cast iron engine blocks (3.29%C and 3.1%C) of two cars--a Proton Saga and a Toyota--were utilized for the experiments. The engine blocks were cut into several small plates and each plate was stamped with some numerical characters at 8 kN load using Instron Table Mounted Universal Testing Machine. The depth of stamping impression varied between 0.2 mm and 0.3 mm. The stamped number was completely ground off manually using a metal file. The grounded surface was then polished smooth using emery papers and etched with a few selected reagents mostly by swabbing. Experimental results showed that a modified Fry's composition consisting of 4 5g CuCl(2), 100 mL HCl, and 180 mL H(2)O restored the number with better contrast at a reasonably shorter time. The above reagent is a slightly modified form of one of the Fry's original compositions--45 g CuCl(2), 180 mL HCl, and 100 mL H(2)O. Quite importantly the proposed reagent restored the original stamped numbers of both Proton and Toyota cars and also a Mitsubishi car that had been obliterated. The most widely used Fry's composition (90 g CuCl(2), 120 mL HCl and 100 mL H(2)O), although recovered the obliterated number, did not cause the desired contrast.
Passive detection of copy-move forgery in digital images: state-of-the-art

Al-Qershi OM, Khoo BE

Forensic Sci Int, 2013 Sep 10;231(1-3):284-95.
PMID: 23890651 DOI: 10.1016/j.forsciint.2013.05.027

Currently, digital images and videos have high importance because they have become the main carriers of information. However, the relative ease of tampering with images and videos makes their authenticity untrustful. Digital image forensics addresses the problem of the authentication of images or their origins. One main branch of image forensics is passive image forgery detection. Images could be forged using different techniques, and the most common forgery is the copy-move, in which a region of an image is duplicated and placed elsewhere in the same image. Active techniques, such as watermarking, have been proposed to solve the image authenticity problem, but those techniques have limitations because they require human intervention or specially equipped cameras. To overcome these limitations, several passive authentication methods have been proposed. In contrast to active methods, passive methods do not require any previous information about the image, and they take advantage of specific detectable changes that forgeries can bring into the image. In this paper, we describe the current state-of-the-art of passive copy-move forgery detection methods. The key current issues in developing a robust copy-move forgery detector are then identified, and the trends of tackling those issues are addressed.
STR data for the 13 CODIS loci in Singapore Malays

Ang HC, Sornarajah R, Lim SE, Syn CK, Tan-Siew WF, Chow ST, et al.

Forensic Sci Int, 2005 Mar 10;148(2-3):243-5.
PMID: 15639622

Allele frequencies for the 13 CODIS (Combined DNA Index System, USA) STR loci included in the AmpFISTR Profiler Plus and AmpFISTR Cofiler kits (Applied Biosystems, Foster City, USA) were determined in a sample of 197 unrelated Malays in Singapore.
A review on the abuse of three NPS (synthetic cannabinoids, kratom, poppers) among youths in Asia

Bae K, Kwon NJ, Han E

Forensic Sci Int, 2018 Nov;292:45-49.
PMID: 30273913 DOI: 10.1016/j.forsciint.2018.09.008

Abuse of new psychoactive substances (NPSs) among youths is increasing at an unprecedented rate all over the world. In Asia, abuse of synthetic cannabinoids (SCs), kratom, and poppers has been reported, but up to date information related to abuse of these three NPSs is lacking. This literature review focuses on the recent abuse of these three NPS among Asian youth. Many studies have been conducted to investigate the abuse statuses of SCs in Asian youth in Turkey, Japan, and Korea, and many cases of kratom abuse have been reported in Malaysia and Thailand. In addition, concerns have been expressed about the use of kratom in combination with other substances by teenagers. Popper abuse has been reported among many young people in Asia, including Korea and China, and many studies on popper abuse have focused on men who have sex with men in China and Malaysia. Since NPS abuse can have severe adverse effects and create social problems, there is a continuing need to investigate NPS abuse status continuously among young people.
Recovering obliterated engraved marks on aluminium surfaces by etching technique

Baharum MI, Kuppuswamy R, Rahman AA

Forensic Sci Int, 2008 May 20;177(2-3):221-7.
PMID: 18313246 DOI: 10.1016/j.forsciint.2008.01.004

A study has been made of the characteristics of restoration of obliterated engraved marks on aluminium surfaces by etching technique. By etching different reagents on 0.61mm thick sheets of aluminium (99wt%) on which some engraved marks had been erased to different depths it was found that the reagent 60% hydrochloric acid and 40% sodium hydroxide on alternate swabbing on the surfaces was found to be the most sensitive one for these metal surfaces. This reagent was able to restore marks in the above plates erased down to 0.04mm below the bottom of the engraving. The marks also presented excellent contrast with the background. This reagent was further experimented with similar aluminium surfaces, but of relatively greater thickness of 1.5mm. It was noticed that the recovery depth increased slightly to 0.06mm; this suggested the dependence of recovery depth on the thickness of the sheet metal. Further, the depth of restoration decreased in cases where the original number was erased and over which a new number was engraved; the latter results are similar to those of steel surfaces reported earlier [M.A.M. Zaili, R. Kuppuswamy, H. Harun, Restoration of engraved marks on steel surfaces by etching technique, Forensic Sci. Int. 171 (2007) 27-32].
Validation of Cameriere's third molar maturity index alone and in combination with apical maturity of permanent mandibular second molar for indicating legal age of 14 years in a sample of South Indian children

Balla SB, Banda TR, Galic I, N NM, Naishadham PP

Forensic Sci Int, 2019 Apr;297:243-248.
PMID: 30844636 DOI: 10.1016/j.forsciint.2019.02.009

The aims of the present study were to validate the discriminatory potential of Cameriere's third molar maturity index (I3M) cut-off value of I3M
Revealing obliterated engraved marks on high strength aluminium alloy (AA7010) surfaces by etching technique

Bong YU, Kuppuswamy R

Forensic Sci Int, 2010 Feb 25;195(1-3):86-92.
PMID: 20022189 DOI: 10.1016/j.forsciint.2009.11.018

Restoration of obliterated engraved marks on high strength Al-Zn-Mg-Cu alloy (AA7010) surfaces by etching technique was studied. The alloy surfaces were mechanically engraved with some identification marks using "Gravograph". The marks were then erased by removing the metal to different levels up to and below the depth of engraving. Five metallographic reagents were tested on the obliterated surfaces by etching. The following two methods (i) immersion in 10% aq. phosphoric acid and (ii) alternate swabbing of 60% HCl and 40% NaOH were found to be quite effective to reveal the obliterated marks. These two procedures were also able to show effectively the marks obliterated by over-engraving and centre punching. Of the two techniques immersion in phosphoric acid provided more contrast. Interestingly, alternate swabbing of 60% HCl and 40% NaOH presented itself to be the common reagent for restoration on pure aluminium as well as its alloy surfaces. This is evident from our own current experiments and those of earlier researchers [G. Peeler, S. Gutowski, H. Wrobel, G. Dower, The restoration of impressed characters on aluminium alloy motor cycle frames, J. Forensic Ident. 58 (1) (2008) 27-32; M. Izhar M. Baharum, R. Kuppuswamy, A.A. Rahman, Restoration of engraved marks on aluminium surfaces by etching technique, Forensic Sci. Int. 177 (2008) 221-227]. The findings have assumed importance as engines and chassis of cars and frames of firearms are currently made of high strength aluminium alloys and recovery on these surfaces by current methods is not satisfactory.
Correlation and assessment of coronary artery luminal stenosis: Post-mortem computed tomography angiogram versus histopathology

Chainchel Singh MK, Abdul Rashid SN, Abdul Hamid S, Mahmood MS, Feng SS, Mohd Nawawi H, et al.

Forensic Sci Int, 2020 Mar;308:110171.
PMID: 32032870 DOI: 10.1016/j.forsciint.2020.110171

BACKGROUND: Post-mortem Computed Tomography (PMCT) allows non-invasive or minimally invasive detection of findings that may or may not be visible during conventional autopsy, however, it does not allow the investigator to draw any conclusions regarding patency of the vessel's lumen. To address this deficiency, Post-mortem Computed Tomography Angiography (PMCTA) utilizing different contrast media and techniques have been introduced with various studies looking at the correlation between PMCTA, autopsy (gross) findings and coronary artery histology in diagnosing coronary artery disease.
OBJECTIVES: The aim of this study is to investigate the sensitivity and specificity of PMCTA in diagnosing coronary artery stenosis using water-based contrast media introduced though the vessels of the neck, compared to the gold standard of diagnosis i.e. gross and histological evaluation of the coronary artery.
METHOD: This was a cross sectional study of 158 arterial sections involving 37 subjects recruited from the National Institute of Forensic Medicine (IPFN), Hospital Kuala Lumpur (HKL). An unenhanced PMCT was performed followed by PMCTA using water-based contrast media introduced though the vessels of the neck. Coronary artery stenosis was determined using multiplanar reconstructionD while the degree of stenosis was determined by calculating the percentage of luminal diameter divided by the diameter of the vessel internal elastic.
RESULTS: The analysis of PMCTA and histopathology examinations revealed a sensitivity of 61.5%, specificity of 91.7%; positive predictive value (PPV) of 40.0% and negative predictive value (NPV) of 96.4%.
CONCLUSION: PMCTA utilizing water-based contrast introduced though the vessels of the neck yielded similar results as other methods and techniques of PMCTA. We would therefore conclude that PMCTA utilizing this technique could be used to assess the degree of calcification and the presence of significant stenosis.
A distinct Y-STR haplotype for Amelogenin negative males characterized by a large Y(p)11.2 (DYS458-MSY1-AMEL-Y) deletion

Chang YM, Perumal R, Keat PY, Yong RY, Kuehn DL, Burgoyne L

Forensic Sci Int, 2007 Mar 2;166(2-3):115-20.
PMID: 16765004

The use of STR multiplexes with the incorporated gender marker Amelogenin is common practice in forensic DNA analysis. However, when a known male sample shows a dropout of the Amelogenin Y-allele, the STR system falsely genotypes it as a female. To date, our laboratory has observed 18 such cases: 12 from our Y-STR database and six from casework. A study on 980 male individuals in the Malaysian population using the AmpFlSTR Y-filer has revealed a distinct Y-chromosome haplotype associated with the Amelogenin nulls. Our results showed that whilst the Amelogenin nulls were noticeably absent among the Chinese, both the Indians and Malays exhibited such mutations at 3.2 and 0.6%, respectively. It was also found that the Amelogenin negative individuals predominantly belonged to the J2e lineage, suggesting the possibility of a common ancestor for at least some of these chromosomes. The null frequencies showed concordance with the data published in Chang et al. [Higher failures of Amelogenin sex test in an Indian population group, J. Forensic Sci. 48 (2003) 1309-1313] on a smaller Malaysian population of 338 males which used a Y-STR triplex. In the current study, apart from the absence of the Amelogenin Y-locus, a complete absence of the DYS458 locus in all the nulls was also observed. This study together with the 2003 study has indicated a similar deletion region exists on the Y(p)11.2 band in all the 18 Y-chromosomes. Using bioinformatics, this deletion has been mapped to a region of at least 1.13 Mb on the Y(p)11.2 encompassing the Amelogenin, MSY1 minisatellite and DYS458 locus. Further, the Y-filer haplotypes revealed an additional null at Y-GATA H4 in two of the Indian males presented here.
Haplotype diversity of 16 Y-chromosomal STRs in three main ethnic populations (Malays, Chinese and Indians) in Malaysia

Chang YM, Perumal R, Keat PY, Kuehn DL

Forensic Sci Int, 2007 Mar 22;167(1):70-6.
PMID: 16457976

We have analyzed 16 Y-STR loci (DYS456, DYS389I, DYS390, DYS389II, DYS458, DYS19, DYS385a/b, DYS393, DYS391, DYS439, DYS635 or Y-GATA C4, DYS392, Y-GATA H4, DYS437, DYS438 and DYS448) from the non-recombining region of the human Y-chromosome in 980 male individuals from three main ethnic populations in Malaysia (Malay, Chinese, Indian) using the AmpFlSTR((R)) Y-filertrade mark (Applied Biosystems, Foster City, CA). The observed 17-loci haplotypes and the individual allele frequencies for each locus were estimated, whilst the locus diversity, haplotype diversity and discrimination capacity were calculated in the three ethnic populations. Analysis of molecular variance indicated that 88.7% of the haplotypic variation is found within population and 11.3% is between populations (fixation index F(ST)=0.113, p=0.000). This study has revealed Y-chromosomes with null alleles at several Y-loci, namely DYS458, DYS392, DYS389I, DYS389II, DYS439, DYS448 and Y-GATA H4; and several occurrences of duplications at the highly polymorphic DYS385 loci. Some of these deleted loci were in regions of the Y(q) arm that have been implicated in the occurrence of male infertility.
Analysis of the D1S80 locus by amplified fragment length polymorphism technique in the Chinese, Malays and Indians in Singapore

Chuah SY, Tan WF, Yap KH, Tai HE, Chow ST

Forensic Sci Int, 1994 Oct 21;68(3):169-80.
PMID: 7982636

The distributions of the D1S80 alleles and genotypes in the Chinese, Malays and Indians in Singapore were determined by amplified fragment length polymorphism (AMP-FLP) analysis. The distributions of the observed genotypes for the three races conformed to Hardy-Weinberg expectations. The system was applied to 19 families whose paternity had been established by restriction fragment length polymorphism (RFLP) analysis. In all cases, Mendelian inheritance of the alleles at the D1S80 locus could be demonstrated. D1S80 typing on DNA recovered by differential extraction of forensic specimens which included vaginal swabs, urethral swabs and seminal stains yielded consistent results.
Oryong 501 sinking incident in the Bering Sea-International DVI cooperation in the Asia Pacific

Chung NE, Castilani A, Tierra WE, Beh P, Mahmood MS

Forensic Sci Int, 2017 Sep;278:367-373.
PMID: 28806635 DOI: 10.1016/j.forsciint.2017.07.030

On December 1st, 2014, the sinking of Oryong 501 occurred in the Bering Sea off the east coast of Russia. A total of 60 crew members, including 35 Indonesians, 13 Filipinos, 11 South Koreans and 1 Russian inspector were on board out of which only seven survived. Through an international rescue operation, the dead bodies of 27 were found and the remaining 26 crew are still missing. After transferring the dead bodies to the Busan Harbor in South Korea, the operation to identify the deceased began involving DVI teams from three countries: Korea, Indonesia and the Philippines. When a deep sea fishing boat sinks, it is very difficult to obtain antemortem data of the crew who had been on board for a long time. This is especially so if the crews are multinational. Further, the accuracy of the antemortem data provided by the families may be questionable, and the provided data is often not standardized. Despite the fact that the antemortem data were received in different formats, the identification process for the bodies of the 27 crew from the Oryong sinking was quickly completed through the cooperation among the three DVI teams. This case is an excellent example of how efficiently a DVI operation can be conducted in the Asia Pacific region. Issues raised during this operation should enable even better preparation for similar events in the future.
Study on the performance of different craniofacial superimposition approaches (II): Best practices proposal

Damas S, Wilkinson C, Kahana T, Veselovskaya E, Abramov A, Jankauskas R, et al.

Forensic Sci Int, 2015 Dec;257:504-508.
PMID: 26482539 DOI: 10.1016/j.forsciint.2015.07.045

Craniofacial superimposition, although existing for one century, is still a controversial technique within the scientific community. Objective and unbiased validation studies over a significant number of cases are required to establish a more solid picture on the reliability. However, there is lack of protocols and standards in the application of the technique leading to contradictory information concerning reliability. Instead of following a uniform methodology, every expert tends to apply his own approach to the problem, based on the available technology and deep knowledge on human craniofacial anatomy, soft tissues, and their relationships. The aim of this study was to assess the reliability of different craniofacial superimposition methodologies and the corresponding technical approaches to this type of identification. With all the data generated, some of the most representative experts in craniofacial identification joined in a discussion intended to identify and agree on the most important issues that have to be considered to properly employ the craniofacial superimposition technique. As a consequence, the consortium has produced the current manuscript, which can be considered the first standard in the field; including good and bad practices, sources of error and uncertainties, technological requirements and desirable features, and finally a common scale for the craniofacial matching evaluation. Such a document is intended to be part of a more complete framework for craniofacial superimposition, to be developed during the FP7-founded project MEPROCS, which will favour and standardize its proper application.
Comparison on three classification techniques for sex estimation from the bone length of Asian children below 19 years old: an analysis using different group of ages

Darmawan MF, Yusuf SM, Kadir MR, Haron H

Forensic Sci Int, 2015 Feb;247:130.e1-11.
PMID: 25540897 DOI: 10.1016/j.forsciint.2014.11.007

Sex estimation is used in forensic anthropology to assist the identification of individual remains. However, the estimation techniques tend to be unique and applicable only to a certain population. This paper analyzed sex estimation on living individual child below 19 years old using the length of 19 bones of left hand applied for three classification techniques, which were Discriminant Function Analysis (DFA), Support Vector Machine (SVM) and Artificial Neural Network (ANN) multilayer perceptron. These techniques were carried out on X-ray images of the left hand taken from an Asian population data set. All the 19 bones of the left hand were measured using Free Image software, and all the techniques were performed using MATLAB. The group of age "16-19" years old and "7-9" years old were the groups that could be used for sex estimation with as their average of accuracy percentage was above 80%. ANN model was the best classification technique with the highest average of accuracy percentage in the two groups of age compared to other classification techniques. The results show that each classification technique has the best accuracy percentage on each different group of age.
Profiling of morphine and codeine in urine after the ingestion of curry containing poppy seed as an evidence for opiates defence in Malaysia

Gan CY, Zainuddin Z, Muhamad Noh H, Rahmat R, Mohd Akir F, Mahad NH, et al.

Forensic Sci Int, 2019 Sep;302:109865.
PMID: 31279278 DOI: 10.1016/j.forsciint.2019.06.023

Consumption of curry containing poppy seeds has raised an issue concerning the opiate content in the urine that might exceed the cut-off value (300ng/mL). The main objective of this study was to examine the morphine and codeine contents in the urine of the consumers after partaking poppy seed-enriched curry in. The volunteers were asked to partake: (a) a single meal and their urines were collected within 24h, or (b) Two meals a day for three consecutive days and their urines were collected within 72h. Two different dosages were also tested in this study: (a) low dosage: 1g/100ml curry (containing 138μg of morphine and 66μg of codeine) and (b) high dosage: 5g/100ml curry (containing 690μg of morphine and 330μg of codeine). The subjects were randomised into the groups using the method of stratified randomization with age and gender groups as covariates. A total of 6 subjects was allocated for each group and placebos were used as control. Results showed that all subjects who consumed low dosage of poppy seeds either in single meal or multiple meals experiment were found negative. However, 1 out of 6high dosage subjects was confirmed positive at a period of 3-6h after the consumption of curry in the single meal study. This outlier maybe due to the lack of water consumption after consuming the curry, thus the low volume of urine was collected and the opiate was concentrated in the urine. On the other hand, 5 out of 6high dosage subjects in the multiple meals experiment were found positive. Majority of these subjects were found positive on the second and third day of the experiment after the second curry meal was consumed. The outlier (negative) in this group might be due to the high consumption of water throughout the experiment and the subject's urine volumes and frequency of urine collection were much higher compared to other subjects. From the result of this study, it can be concluded that partaking high dosages of poppy seed in curry could give a positive response (>300ng/ml+uncertainty of measurement) in the urine, and the water consumption after partaking curry has significant influence for the opiate contents in the urine.
The post-mortem resilience of facial creases and the possibility for use in identification of the dead

Hadi H, Wilkinson CM

Forensic Sci Int, 2014 Apr;237:149.e1-149.e7.
PMID: 24613011 DOI: 10.1016/j.forsciint.2013.12.014

The post-mortem resilience of facial creases was studied using donated bodies in order to establish the efficacy of crease analysis for identification of the dead. Creases were studied on normal (pre-embalmed) and bloated (embalmed) cadavers at the Centre for Anatomy and Human Identification (CAHID) to establish whether facial bloating would affect facial crease visibility. Embalming was chosen to simulate the effects produced by post-mortem bloating. The results suggested that creases are resilient and changes were only detected for creases located on the periphery of the face, particularly at areas where the skin is thick, such as at the cheeks. Two new creases not previously classified were identified; these creases were called the vertical superciliary arch line and the lateral nose crease. This research suggests that facial creases may be resilient enough after death to be utilised for human identification.
Development of an objective method for the comparison of fired projectiles using an air pistol as a template

Hamzah NH

Forensic Sci Int, 2016 07;264:106-12.
PMID: 27081766 DOI: 10.1016/j.forsciint.2016.03.050

The ability to objectify ballistic evidence is a challenge faced by firearms examiners around the world. A number of researchers are trying to improve bullet-identification systems to address deficiencies detailed within the National Academy of Science report (2009). More recently focus has turned to making use of more sophisticated imaging modalities to view entire regions of the projectile and the development of automated systems for the comparison of the topographical surfaces recorded. Projectiles from a newly bought air pistol with 0.177 calibre pellets (unjacketed), fired series of 609 pellets were examined using an optical microscope. A mathematical methodology was developed to pre-process the resultant topographical maps generating point data for comparison, analysed using the principal component analysis (PCA). In most cases limited to reasonable success was achieved. The objective method still requires an operator to identify the Land Engraved Areas to be scanned, however the mathematical alignments were objectively achieved. The PCA results illustrated that the striation marks were neither exclusive nor specific to the LEA regions but rather crossed over regions. This study also proves that a single weapon does not necessarily leave identical marks of projectiles on its surface.
Practical relevance of prescribing superimposition for determining a frontal sinus pattern match

Hashim N, Hemalatha N, Thangaraj K, Kareem A, Ahmed A, Hassan NF, et al.

Forensic Sci Int, 2015 Aug;253:137.e1-7.
PMID: 26103928 DOI: 10.1016/j.forsciint.2015.05.020

A research that tested the methods suitable for comparing ante- and post-mortem radiographic patterns of frontal sinuses concluded that superimposition should be followed as a stringent method for establishing individual identification. We verified the practical relevance of prescribing superimposition by superimposing ante- and post-mortem frontal sinus patterns recorded in case situations as well as simulated ante- and post-mortem of frontal sinus patterns recorded using archived skulls. For superimposition, the wipe facility available in the vision mixer was employed in addition to the mix mode. Ante- and post-mortem radiographic patterns that were available in two earlier cases were not superimposable. Related simulated ante- and post-mortem radiographic patterns of frontal sinuses are superimposable only when the skull that is initially oriented for recording the ante-mortem radiograph is retained in the same posture for recording the post-mortem radiograph also. Once the skull has been removed from the X-ray table, after recording the simulated ante-mortem radiograph, and repositioned for the simulated post-mortem radiograph, even when the intervening time is 1min, the sinus patterns in these radiographs are not superimposable. Superimposition cannot be used as a conditional requirement for side-by-side comparison of radiographic patterns of frontal sinuses.

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