Individual identification of disguised faces by morphometrical matching

The reliability of a morphometrical matching method for identifying disguised faces was examined experimentally using a computer-assisted facial image identification system. The 2D right oblique facial images of three target persons disguised with sunglasses, cap and gauze mask were each compared with each of the 3D facial images of 100 subjects, yielding 900 face-to-face superimpositions. The average perpendicular distance between the facial outlines and the average point-to-point distance of the corresponding landmarks in the 2D image of the disguised face and the 3D facial image, were calculated. As a matching criterion, the sum of the values of the average perpendicular difference of the facial outlines and the average point-to-point difference between the corresponding landmarks was used (abbreviation: average difference).The range of the average difference was 2.3-2.8mm for the same person (a match) and 4.0-14.6mm for different (non-matching) people, respectively. The ranges for matching and non-matching faces did not overlap. Even the 3D facial images of the non-matching person showing the closest value of average difference to the average difference for the matching person could be excluded easily. It was concluded that the morphometrical matching method can reliably identify disguised faces and the results produced by this method could be easily understandable by a court of law.     

Weight of authorship evidence with multiple categories of stylometric features: A multinomial-based discrete model

This study empirically demonstrates the efficacy of a two-level Dirichlet-multinomial statistical model (the Multinomial system) for computing likelihood ratios (LR) for linguistic, textual evidence with multiple stylometric feature types with discrete values. The LRs are calculated separately for each feature type, namely, word, character and part of speech N-grams (N = 1,2,3), which are combined as overall LRs through logistic regression fusion. The Multinomial system’s performance is compared with that of a previously proposed system with the cosine distance (the Cosine system) using the same data (i.e., documents collated from 2160 authors). The experimental results show that: (1) the Multinomial system outperforms the Cosine system with the fused feature types by a log-LR cost of ca. 0.01 ～ 0.05 bits; and (2) the Multinomial system is more advantageous in performance with longer documents than the Cosine system. Although the Cosine system is more robust overall against the sampling variability arising from the number of authors included in the reference and calibration databases, the Multinomial system can achieve reasonable stability in performance; for example, the standard deviation value of the log-LR cost becomes lower than 0.01 (10 random samplings of authors for the reference and calibration databases) with 60 or more authors in each database.     

Computer-assisted skull identification system using video superimposition

This system consists of two main units, namely a video superimposition system and a computer-assisted skull identification system. The video superimposition system is comprised of the following five parts: a skull-positioning box having a monochrome CCD camera, a photo-stand having a color CCD camera, a video image mixing device, a TV monitor and a videotape recorder. The computer-assisted skull identification system is composed of a host computer including our original application software, a film recorder and a color printer. After the determination of the orientation and size of the skull to those of the facial photograph using the video superimposition system, the skull and facial photograph images are digitized and stored within the computer, and then both digitized images are superimposed on the monitor. For the assessment of anatomical consistency between the digitized skull and face, the distance between the landmarks and the thickness of soft tissue of the anthropometrical points are semi-automatically measured on the monitor. The wipe images facilitates the comparison of positional relationships between the digitized skull and face. The software includes the polynomial functions and Fourier harmonic analysis for evaluating the match of the outline such as the forehead and mandibular line in both the digitized images.     

On using gait in forensic biometrics

Given the continuing advances in gait biometrics, it appears prudent to investigate the translation of these techniques for forensic use. We address the question as to the confidence that might be given between any two such measurements. We use the locations of ankle, knee, and hip to derive a measure of the match between walking subjects in image sequences. The Instantaneous Posture Match algorithm, using Harr templates, kinematics, and anthropomorphic knowledge is used to determine their location. This is demonstrated using real CCTV recorded at Gatwick International Airport, laboratory images from the multiview CASIA-B data set, and an example of real scene of crime video. To access the measurement confidence, we study the mean intra- and inter-match scores as a function of database size. These measures converge to constant and separate values, indicating that the match measure derived from individual comparisons is considerably smaller than the average match measure from a population.     

A new experimental approach to computer-aided face/skull identification in forensic anthropology

The present study introduces a new approach to computer-assisted face/skull matching used for personal identification purposes in forensic anthropology.In this experiment, the authors formulated an algorithm able to identify the face of a person suspected to have disappeared, by comparing the respective person's facial image with the skull radiograph. A total of 14 subjects were selected for the study, from which a facial photograph and skull radiograph were taken and ultimately compiled into a database, saved to the hard drive of a computer. The photographs of the faces and corresponding skull radiographs were then drafted using common photographic software, taking caution not to alter the informational content of the images. Once computer generated, the facial images and menu were displayed on a color monitor. In the first phase, a few anatomic points of each photograph were selected and marked with a cross to facilitate and more accurately match the face with its corresponding skull. In the second phase, the above mentioned cross grid was superimposed on the radiographic image of the skull and brought to scale. In the third phase, the crosses were transferred to the cranial points of the radiograph. In the fourth phase, the algorithm calculated the distance of each transferred cross and the corresponding average. The smaller the mean value, the greater the index of similarity between the face and skull.A total of 196 cross-comparisons were conducted, with positive identification resulting in each case. Hence, the algorithm matched a facial photograph to the correct skull in 100% of the cases.     

Forensic genetic analysis of mitochondrial DNA hypervariable region I/II sequences: an expanded Korean population database

We have analyzed variation of the mitochondrial DNA (mtDNA) hypervariable segments I and II (HVS-I and HVS-II) in 185 randomly chosen individuals from Korea to provide an expanded and reliable Korean database. Combined sequence comparison of HVS-I and HVS-II led to the identification of 167 different haplotypes characterized by 154 variable sites. One hundred and fifty-one of the haplotypes were individual-specific, 14 were found in two individuals and 2 were found in three individuals. A pairwise comparison of the 185 HVS-I/II sequences found an average of 10.11 +/- 4.63 differences between individuals. The random match probability and gene diversity for the combined hypervariable regions were estimated at 0.66% and 0.9988, respectively. Analyzing the expanded database including three previously reported data sets and the present data using haplogroup-based comparisons and comparison with closely related sequences allowed errors to be detected and eliminated, thus considerably improving data quality. Sample division comparisons based on PhiST genetic distance measures revealed no significant population differentiation in the distribution of mtDNA sequence variations between the present data set and a database in The Scientific Working Group on DNA Analysis Methods (SWGDAM), but did indicate differences from other sets of data. Based on the results of mtDNA profiles, almost all of the mtDNA types studied here could be classified into subsets of haplogroups common in east Asia, and show that the Koreans possess lineages from both the southern and the northern haplogroup complexes of east Asian populations. The new data, combined with other mtDNA sequences, demonstrate how useful comparison with closely related mtDNA sequences can be for improving database quality, as well as providing haplotype information for forensic and population genetic analyses in the Korean population.     

Computer-assisted facial image identification system using a 3-D physiognomic range finder

This system consists of a 3-D physiognomic range finder and a computer-assisted facial image superimposition unit. The 3-D range finder is composed of a detector for measuring facial surface and its control computer. The detector has two sinusoidal grating projection devices and two CCD cameras. The computer-assisted facial image superimposition unit consists of a host computer including a proprietary software, a flat surface color display and a color image scanner for inputting 2-D facial images of a criminal. The 3-D facial shape and texture of a suspect is obtained by using the range finder. To make the comparison between the 3-D facial image and the 2-D facial image, the 3-D facial image is first reproduced on a display of the host computer from a MO disk and then the 2-D facial image is taken with the color image scanner and reproduced on the display. The 3-D facial image is exactly adjusted to match the orientation and size of the 2-D facial image under the fine framework mode, and then the fine framework mode of 3-D facial image is converted to the fine texture image. The shape and positional relationships of facial components between the 3-D and 2-D facial images are examined by the fade-out or wipe image mode. The distance between the selected two points and angle among the selected three points on the 3-D and 2-D facial images are automatically measured for the assessment of anthropometrical data between both images. For evaluating the fit between the anthropometrical points on the 3-D and 2-D facial images, the reciprocal point-to-point difference between both images is compared.     

Comparing the performance of IBIS and BulletTRAX-3D technology using bullets fired through 10 consecutively rifled barrels

This study evaluates the abilities of the Integrated Ballistics Identification System (IBIS) and BulletTRAX-3D electronic imaging systems to identify bullets fired by the same weapon in a large database of images. Ten consecutively rifled handgun barrels were test fired to obtain reference sample and known match sample pairs for upload onto both bullet acquisition systems. Both copper-jacketed and lead bullets were uploaded, to account for variations in the manner in which markings are reproduced on the different metal compositions. Ranked correlation lists were examined and evaluated. For copper-jacketed bullet correlations, both IBIS and BulletTRAX-3D identified all reference samples to their known matches within the top 10 positions. For lead bullets, BulletTRAX-3D identified all reference samples to their known match in the top 10 positions while IBIS identified only 30%. For inter composition comparisons, BulletTRAX-3D was more successful than IBIS, identifying 100% of reference samples to their known match in the top 20 for copper-jacketed to lead comparisons and 90% for lead to copper-jacketed comparisons. These results suggest that BulletTRAX-3D is more effective than IBIS in the analysis of a wider range of bullet types and it was also found to produce images of superior quality.     

A new retrieval system for a database of 3D facial images

A new retrieval system for a 3D facial image database was designed and its reliability was experimentally examined. This system has two steps, firstly to automatically adjust the orientation of all 3D facial images in a database to that of the 2D facial image of a target person, and then to identify the facial image of the target person from the adjusted 3D facial images in the database using a graph-matching method. From the experimental study [M. Yoshino, K. Imaizumi, T. Tanijiri, J.G. Clement, Automatic adjustment of facial orientation in 3D face image database, Jpn. J. Sci. Tech. Iden. 8 (2003) 41-47], it is concluded that the software developed for the first step will be applicable to the automatic adjustment of facial orientation in the 3D facial image database. In 28 out of 110 sets (25.5%), the 3D image of the target person was chosen as the best match (from a database of 132 3D facial images) according to the similarity of the facial image characteristics based on the graph matching. The 3D facial image of the target person was ranked in the top of 10 of the database in 75 out of 110 sets (68.2%). These results suggest that this system is inadequate for the identification level, but may be feasible for screening method in a small database. It will be necessary to further pursue the possibility of realization of a facial image retrieval system for a large database such as suspects' facial images in future.     

Determination of average vehicle speed utilizing reverse projection

Reverse projection photogrammetry has long been used to estimate the height of an individual in forensic video examinations. A natural extrapolation would be to apply the same technique on a video to estimate the speed of an object by determining the distance traveled between two points over a set amount of time. To test this theory, five digital video recorders (DVRs) were connected to a single fixed camera to record a vehicle traveling down a track. The vehicle's speed was measured through Doppler radar by a trained operator and the speedometer of the vehicle was also recorded with a video camera. The recorded video was examined and the frames that best depict the beginning and end of the vehicles course were selected. Two reverse projection photogrammetric examinations were performed on the selected frames to establish the position of the vehicle. The distance between the two points was measured, and the time elapsed between the two points was examined. The outcome provided an accurate speed result with a standard degree of uncertainty. This study proves the feasibility of using video data and reverse projection photogrammetry to determine the speed of a vehicle with a limited set of variables. Further research is needed to determine how additional variables would impact the standard degree of uncertainty.     

视频方法鉴定车速的准确性研究

目的通过实验研究用视频方法鉴定车速结果的准确性及其影响因素。方法在选定的实验场地上,让实验车辆以一定速度匀速通过一段距离,使用高空、垂直、斜角和车载四个位置的摄像机同时录制,将车速计算结果进行比较。结果理论和实验数据分析表明,误差的大小主要取决于:车速和帧速率,车体上参考点和路上参考点的对齐效果,还有行车距离的大小和播放器屏幕的大小等。结论用视频方法进行车速鉴定,相对于传统的用力学公式进行计算,其准确性和可信度较好;一般条件下,误差可在5%~10%之间估算;夜晚条件下,可在车灯的轮廓线上选择车体上参考点,炫目情况除外。     

Robust Shoeprint Retrieval Method Based on Local‐to‐Global Feature Matching for Real Crime Scenes

In this study, an automatic and robust crime scene shoeprint retrieval method is proposed. As most shoeprints left at crime scenes are randomly partial and noisy, crime scene shoeprint retrieval is a challenging task. To handle partial, noisy shoeprint images, we employ denoising deep belief network (DBN) to extract local features and use spatial pyramid matching (SPM) to obtain a local‐to‐global matching score. In this study, 536 query shoeprint images from crime scenes and a large scale database containing 34,768 shoeprint images are used to evaluate the retrieval performance. Experimental results show that the proposed method outperforms other state‐of‐the‐art methods in terms of retrieval accuracy, feature dimension, and retrieval speed. The proposed method achieves a cumulative match score (CMS) of 65.67% at top 10 which is 5.60% higher than the second best performing method.     

Accuracy of BR Regression Equation for Impacted Teeth in Age Estimation in Haryana Population of India

Abstract:  Dental cementum is a vital tissue that demonstrates continuous apposition throughout the life of a tooth. Positive correlation has been reported between the coronal displacement of cementum and age in impacted teeth and BR regression equation has been proposed. The present study is an attempt to calculate accuracy of BR regression equation in Haryana population of India. The study was conducted on 20 impacted mandibular third molars extracted from healthy patients, aged between 22 and 32 years. The bucco-lingual ground sections were prepared and the distance between the edges of enamel and cementum were measured with micrometer attached to a light microscope and BR regression equation was applied for age estimation. Although the estimated age with BR regression equation was less than chronological age it was not statistically significant. Hence, the BR regression equation can be used in medicolegal as well as in forensic odontology for age estimation.     

Simulation-based reconstruction of traffic incidents from moving vehicle mono-camera

Video recordings from digital cameras implemented in road vehicles present a valuable source of data concerning various dangerous traffic situations, i.e., road accidents or near-miss incidents. This data is readily available and numerous methods for forensic reconstruction of traffic situations from vehicle video were presented in the past. New alternative method for reconstruction of traffic situations from vehicle video is presented in this article. The method is based on the fusion of kinetic vehicle trajectory simulation within 3D laser scanner point cloud, projective geometry, and processing of video footage from moving vehicle camera. The method offers accurate reconstruction of general vehicle motion within relevant time domain whereby in-depth technical information about traffic incident can be quantitatively extracted from video footage. The result is physics-based 3D projection of simulated vehicle motion on the motion of real vehicle recorded by moving monocular camera. The method was validated within performed experimental test runs with respect to vehicle speed, distance travelled, acceleration/deceleration and directional quantities (yaw rate, yaw angle). The method was further applied in the reconstruction of real-world traffic events.     

The results of a randomized controlled trial of police body-worn video in Australia

Journal of Experimental Criminology - We report the results of a randomized controlled trial of police body-worn video (BWV) cameras in an Australian context, with a focus on how cameras influence...     

A population genetic database of cat breeds developed in coordination with a domestic cat STR multiplex

A simple tandem repeat (STR) PCR-based typing system developed for the genetic individualization of domestic cat samples has been used to generate a population genetic database of domestic cat breeds. A panel of 10 tetranucleotide STR loci and a gender-identifying sequence tagged site (STS) were co-amplified in genomic DNA of 1043 individuals representing 38 cat breeds. The STR panel exhibits relatively high heterozygosity in cat breeds, with an average 10-locus heterozygosity of 0.71, which represents an average of 38 breed-specific heterozygosities for the 10-member panel. When the entire set of breed individuals was analyzed as a single population, a heterozygosity of 0.87 was observed. Heterozygosities obtained for the 10 loci range from 0.72 to 0.96. The power for genetic individualization of domestic cat samples of the multiplex is high, with a probability of match (p(m)) of 6.2E-14, using a conservative θ = 0.05.     

Survey of 1276 shoeprint impressions and development of an automatic shoeprint pattern matching facility.

1276 shoeprints were collected at a scientific exhibition. Details regarding the age groups of the participants, style, size and manufacturer/brand of their shoes were recorded. The impressions were assigned to pattern groups showing that the most common pattern was present in only 1% of the population studied and most patterns were much less common. The impressions were digitized and a system developed for automatically sorting a database of images of outsole patterns in response to a reference image. The database images are ranked so that those from the same pattern group as the reference shoeprint are likely to be at the start of the list. A database of 486 complete shoeprint images belonging to 142 pattern groups was established with each group containing two or more examples. Tests of the system have shown that the first-ranked database image belongs to the same pattern group as the reference image 60% of the time and that a correct match appears within the first 5% of the ranked images 88% of the time. The system has translational and rotational invariance so that the spatial positioning of the reference shoeprint images does not have to correspond with the spatial positioning of the shoeprint images of the database. The performance of the system for matching partial shoeprints was also determined.     

Cocaine profiling for strategic intelligence, a cross-border project between France and Switzerland: part II. Validation of the statistical methodology for the profiling of cocaine

Harmonisation and optimization of analytical and statistical methodologies were carried out between two forensic laboratories (Lausanne, Switzerland and Lyon, France) in order to provide drug intelligence for cross-border cocaine seizures. Part I dealt with the optimization of the analytical method and its robustness. This second part investigates statistical methodologies that will provide reliable comparison of cocaine seizures analysed on two different gas chromatographs interfaced with a flame ionisation detectors (GC-FIDs) in two distinct laboratories. Sixty-six statistical combinations (ten data pre-treatments followed by six different distance measurements and correlation coefficients) were applied. One pre-treatment (N+S: area of each peak is divided by its standard deviation calculated from the whole data set) followed by the Cosine or Pearson correlation coefficients were found to be the best statistical compromise for optimal discrimination of linked and non-linked samples. The centralisation of the analyses in one single laboratory is not a required condition anymore to compare samples seized in different countries. This allows collaboration, but also, jurisdictional control over data.     

Image matching algorithms for breech face marks and firing pins in a database of spent cartridge cases of firearms

On the market several systems exist for collecting spent ammunition data for forensic investigation. These databases store images of cartridge cases and the marks on them. Image matching is used to create hit lists that show which marks on a cartridge case are most similar to another cartridge case. The research in this paper is focused on the different methods of feature selection and pattern recognition that can be used for optimizing the results of image matching.The images are acquired by side light images for the breech face marks and by ring light for the firing pin impression. For these images a standard way of digitizing the images used. For the side light images and ring light images this means that the user has to position the cartridge case in the same position according to a protocol. The positioning is important for the sidelight, since the image that is obtained of a striation mark depends heavily on the angle of incidence of the light. In practice, it appears that the user positions the cartridge case with +/-10 degrees accuracy.We tested our algorithms using 49 cartridge cases of 19 different firearms, where the examiner determined that they were shot with the same firearm. For testing, these images were mixed with a database consisting of approximately 4900 images that were available from the Drugfire database of different calibers.In cases where the registration and the light conditions among those matching pairs was good, a simple computation of the standard deviation of the subtracted gray levels, delivered the best-matched images. For images that were rotated and shifted, we have implemented a "brute force" way of registration. The images are translated and rotated until the minimum of the standard deviation of the difference is found. This method did not result in all relevant matches in the top position. This is caused by the effect that shadows and highlights are compared in intensity. Since the angle of incidence of the light will give a different intensity profile, this method is not optimal.For this reason a preprocessing of the images was required. It appeared that the third scale of the "à trous" wavelet transform gives the best results in combination with brute force. Matching the contents of the images is less sensitive to the variation of the lighting.The problem with the brute force method is however that the time for calculation for 49 cartridge cases to compare between them, takes over 1 month of computing time on a Pentium II-computer with 333MHz. For this reason a faster approach is implemented: correlation in log polar coordinates. This gave similar results as the brute force calculation, however it was computed in 24h for a complete database with 4900 images.A fast pre-selection method based on signatures is carried out that is based on the Kanade Lucas Tomasi (KLT) equation. The positions of the points computed with this method are compared. In this way, 11 of the 49 images were in the top position in combination with the third scale of the à trous equation. It depends however on the light conditions and the prominence of the marks if correct matches are found in the top ranked position. All images were retrieved in the top 5% of the database. This method takes only a few minutes for the complete database if, and can be optimized for comparison in seconds if the location of points are stored in files.For further improvement, it is useful to have the refinement in which the user selects the areas that are relevant on the cartridge case for their marks. This is necessary if this cartridge case is damaged and other marks that are not from the firearm appear on it.