Photographic Analyses Using Skin Detail of the Hand: A Methodology and Evaluation,

Skin features have been employed by law enforcement agencies for suspect and victim identification. Comparisons of hand have arisen in casework where images have been submitted where a face was not present but a hand was visible. This research utilizes a collection of 128 hands from employees of the U.S. Army Criminal Investigation Laboratory to examine the frequency and distribution of skin detail on the dorsal surface of the hand. To assess the location of features, the hand was segmented into 14 regions using readily discernible anatomical landmarks. Overall, 2618 pigmented lesions and 92 scars or injuries were documented. When comparing the regions with one another, Regions 1–10 had fewer pigmented lesions than Regions 11–14. There was no pattern to the distribution of scars throughout the regions. The findings presented a foundation for one possible method that may differentiate hands based on the frequency and distribution of such features.     

GrinLine Identification Using Digital Imaging and Adobe Photoshop*

Abstract: The purpose of this study was to outline a method by which an antemortem photograph of a victim can be critically compared with a postmortem photograph in an effort to facilitate the identification process. Ten subjects, between 27 and 55 years old provided historical pictures of themselves exhibiting a broad smile showing anterior teeth to some extent (a grin). These photos were termed “antemortem” for the purpose of the study. A digital camera was used to take a current photo of each subject’s grin. These photos represented the “postmortem” images. A single subject’s “postmortem” photo set was randomly selected to be the “unknown victim.” These combined data of the unknown and the 10 antemortem subjects were digitally stored and, using Adobe Photoshop software, the images were sized and oriented for comparative analysis. The goal was to devise a technique that could facilitate the accurate determination of which “antemortem” subject was the “unknown.” The generation of antemortem digital overlays of the teeth visible in a grin and the comparison of those overlays to the images of the postmortem dentition is the foundation of the technique. The comparisons made using the GrinLine Identification Technique may assist medical examiners and coroners in making identifications or exclusions.     

The Possibilities and Limitations of Forensic Hand Comparison

On recordings of certain crimes, the face is not always shown. In such cases, hands can offer a solution, if they are completely visible. An important aspect of this study was to develop a method for hand comparison. The research method was based on the morphology, anthropometry, and biometry of hands. A new aspect of this study was that a manual and automated test were applied, which, respectively, assess many features and provide identification rates quickly. An important observation was that good quality images can provide sufficient hand details. The most distinctive features were the length/width ratio, the palm line pattern and the quantity of highly distinctive features present, and how they are distributed. The results indicate that experience did not improve the identification rates, while the manual test did. Intra‐observer variability did not influence the results, whereas hands of relatives were frequently misjudged. Both tests provided high identification rates.     

Relatively Permanent Pigmented or Vascular Skin Marks for Identification: A Pilot Reliability Study

In child sexual exploitation offenses, the collected evidence images often show the skin of nonfacial body parts of the criminals and victims. For identification in this scenario, “relatively permanent pigmented or vascular skin marks,” abbreviated as RPPVSM, were recently introduced as the basis for a novel biometric trait. This pilot study evaluated the interexaminer variability of RPPVSM identification. Four dermatology physicians were recruited to examine RPPVSM from 75 skin images collected from a total of 51 Caucasian and Asian subjects. The images were separated into 50 reference (“suspect”) images and 25 evaluation (“evidence”) images. The examiners were asked to perform identification by annotating RPPVSM in each of the 25 evaluation images and matching them with the reference images. The rate of misidentification was 0% while the mean rate at which examiners failed to find a match was 6%, indicating the potential of dermatology physicians performing the role of RPPVSM examiners.     

Computer‐aided Dental Identification: An Objective Method for Assessment of Radiographic Image Similarity*

Abstract: A pilot study evaluated a computer‐based method for comparing digital dental images, utilizing a registration algorithm to correct for variations in projection geometry between images prior to a subtraction analysis. A numerical assessment of similarity was generated for pairs of images. Using well‐controlled laboratory settings, the method was evaluated as to its ability to identify the correct specimen with positive results. A subsequent clinical study examined longitudinal radiographic examinations of selected anatomical areas on 47 patients, analyzing the computer‐based method in making the correct identification based upon a threshold level of similarity. The results showed that at a threshold of 0.855, there were two false negative and two false positive identifications out of 957 analyses. Based on these initial findings, 25 dental records having two sets of full mouth series of radiographs were selected. The radiographs were digitized and grouped into six anatomical regions. The more recent set of films served as postmortem images. Each postmortem image was analyzed against all other images within the region. Images were registered to correct for differences in projection geometry prior to analysis. An area of interest was selected to assess image similarity. Analysis of variance was used to determine that there was a significant difference between images from the same individual and those from different individuals. Results showed that the threshold level of concordance will vary with the anatomical region of the mouth examined. This method may provide the most objective and reliable method for postmortem dental identification using intra‐oral images.     

Failure of anthropometry as a facial identification technique using high-quality photographs

Anthropometry can be used in certain circumstances to facilitate comparison of a photograph of a suspect with that of the potential offender from surveillance footage. Experimental research was conducted to determine whether anthropometry has a place in forensic practice in confirming the identity of a suspect from a surveillance video. We examined an existing database of photographic lineups, where one video image was compared against 10 photographs, which has previously been used in psychological research. Target (1) and test (10) photos were of high quality, although taken with a different camera. The anthropometric landmarks of right and left ectocanthions, nasion, and stomion were chosen, and proportions and angle values between these landmarks were measured to compare target with test photos. Results indicate that these measurements failed to accurately identify targets. There was also no indication that any of the landmarks made a better comparison than another. It was concluded that, for these landmarks, this method does not generate the consistent results necessary for use as evidence in a court of law.     

A Preliminary Study of the Reliability of Anatomical Facial Landmarks Used in Facial Comparison

Anatomical landmarks are considered the most objective indicators for use in forensic facial comparisons. Therefore, accurately identifying and locating these landmarks is the beginning of reliable facial comparison. This study evaluated the accuracy with which facial landmarks are located and examined their reliability according to type of landmark, head posture, and image quality. Nine operators located a series of landmarks on prepared facial images used to produce comparison images. Then, the average distances between the reciprocal landmarks (ADRL) on the reference and the comparison images were measured as indicators of landmark reliability. We found that a set of landmarks had higher or lower reliability as a function of the head angle and image quality. More reliable landmarks were associated with certain head postures and degrees of image quality. These should be used for facial comparison analysis depending on various head and image conditions.     

Uniqueness of the Dentition as Impressed in Human Skin: A Cadaver Model*

Abstract: Bitemark interpretation assumes that the human dentition is unique and that its attributes can be accurately transferred to skin. A cadaver model was used to investigate whether the correct biter could be determined from similarly aligned dentitions once the dentitions were impressed in human skin. One‐hundred dental stone models, which were measured and determined to be unique, were divided into 10 groups based upon similarities of mal‐alignment patterns. One model was randomly selected from each group and bites were produced on unembalmed human cadavers. Metric/angular measurements and hollow volume overlays of the models were compared with the bites made. The percentage of dentitions from each group as well as the 100 dental model population that could not be excluded as the biter was determined. Results showed difficulty distinguishing the biter from individuals with similarly aligned dentitions and in some cases, an incorrect biter appeared better correlated to the bite.     

Individual Camera Identification Using Correlation of Fixed Pattern Noise in Image Sensors

Abstract:  This paper presents results of experiments related to individual video camera identification using a correlation coefficient of fixed pattern noise (FPN) in image sensors. Five color charge-coupled device (CCD) modules of the same brand were examined. Images were captured using a 12-bit monochrome video capture board and stored in a personal computer. For each module, 100 frames were captured. They were integrated to obtain FPN. The results show that a specific CCD module was distinguished among the five modules by analyzing the normalized correlation coefficient. The temporal change of the correlation coefficient during several days had only a negligible effect on identifying the modules. Furthermore, a positive relation was found between the correlation coefficient of the same modules and the number of frames that were used for image integration. Consequently, precise individual camera identification is enhanced by acquisition of as many frames as possible.     

Sex Assessment from the Sacral Base by Means of Image Processing

Abstract:  To help improve sex assessment from skeletal remains, the present study considers the diagnostic value of the sacral base (basis osseus sacri) based on its planar image and related metric data. For this purpose, 114 adult sacra of known sex and age from two early 20th century Italian populations were examined, the first from Bologna, northern Italy ( n  = 76), and the second from Sassari, Sardinia ( n  = 38). Digital photos of the sacral base were taken with each bone in a standardized orientation. Technical drawing software was used to trace its profile and to measure related dimensions (area, perimeter, and breadth of S1 and total breadth of the sacrum). The measurements were subjected to discriminant and classification function analyses. The sex prediction success of 93.2% for the Bolognese sample, 81.6% for the Sassarese sample, and 88.3% for the pooled sample indicates that the first sacral vertebra is a good character for sex determination.     

Effect of History and Context on Forensic Pathologist Interpretation of Photographs of Patterned Injury of the Skin

In a previous study, a survey‐based analysis of pathologist diagnoses of patterned injury was performed. Subjects were provided with photographs of “classic” injuries and asked to diagnose the lesion in the absence of history or context. There was a relatively low diagnostic consensus among respondents. A second survey suggested that the disparate answers were not due to a strong belief in different diagnoses, but instead reflected how the respondents dealt with ambiguity. A third survey was created that asked participants to evaluate patterned injuries of the skin, but provided history and contextual information. The addition of history and contextual information increased consensus from a median of 80% to 98% on a per‐question basis. Confidence increased from a median of 56%–92%. These results demonstrate the importance of history and context in medical diagnosis of patterned injuries of the skin.     

Identification from Chest X‐Rays: Reliability of Bone Density Patterns of the Humerus*

Abstract: A critical review of Kahana and Hiss’ study on identification from bone trabecular pattern and a test of their method conducted on the humerus are presented. Bone trabecular pattern was studied through the generation of a numerical file representing the gray scale. Using the correlation coefficient, several pairwise comparisons between numerical files were performed. The test gave nearly 30% of incorrect exclusions (the method did not recognize couples of radiographs belonging to the same subject) and 50% of misidentifications (the method recognized couples of radiographs belonging to different subjects, as belonging to the same subject); therefore, this research shows that at the present time, it is not possible to safely quantify identification through bone density patterns, of the proximal humerus taken from thoracic X‐rays. Thus, an “easy”—but dangerous—use of trabecular density patterns on this specific type of radiogram as an identification method should be currently avoided.     

Quantification of Osteon Morphology Using Geometric Histomorphometrics

Many histological methods in forensic anthropology utilize combinations of traditional histomorphometric parameters which may not accurately describe the morphology of microstructural features. Here, we report the novel application of a geometric morphometric method suitable when considering structures without anatomically homologous landmarks for the quantification of complete secondary osteon size and morphology. The method is tested for its suitability in the measurement of intact secondary osteons using osteons digitized from transverse femoral diaphyseal sections prepared from two human individuals. The results of methodological testing demonstrate the efficacy of the technique when applied to intact secondary osteons. In providing accurate characterization of micromorphology within the robust mathematical framework of geometric morphometrics, this method may surpass traditional histomorphometric variables currently employed in forensic research and practice. A preliminary study of the intersectional histomorphometric variation within the femoral diaphysis is made using this geometric histomorphometric method to demonstrate its potential.     

A Novel Forged Image Detection Method Using the Characteristics of Interpolation

Development of digital image‐editing programs has enabled us to be widely exposed to forged digital images surrounding us. Such forged images have been dispersed through the Internet, newspaper articles, and magazines, and in particular, the information contained in these unverified images happened to be regarded as true. As a result, the forged images provided wrong information for individuals and society, thus sometimes creating social issues. In order to solve such problems, this study was aimed to suggest the methods of identifying the veracity of forged images. In this way, it suggested re‐interpolation algorithm. Namely, the study re‐interpolated in identical arbitrary values both the interpolated and un‐interpolated regions based on the interpolation used a lot in forged, confirmed discrete fourier transform (DFT) characteristics of these two regions, and embodied a detection map for the final forged images, using the subtraction value between two regions in DFT characteristics.     

A Novel Method for the Photographic Recovery of Fingermark Impressions from Ammunition Cases Using Digital Imaging

The photographic preservation of fingermark impression evidence found on ammunition cases remains problematic due to the cylindrical shape of the deposition substrate preventing complete capture of the impression in a single image. A novel method was developed for the photographic recovery of fingermarks from curved surfaces using digital imaging. The process involves the digital construction of a complete impression image made from several different images captured from multiple camera perspectives. Fingermark impressions deposited onto 9‐mm and 0.22‐caliber brass cartridge cases and a plastic 12‐gauge shotgun shell were tested using various image parameters, including digital stitching method, number of images per 360° rotation of shell, image cropping, and overlap. The results suggest that this method may be successfully used to recover fingermark impression evidence from the surfaces of ammunition cases or other similar cylindrical surfaces.     

The Response of Skin to Applied Stress: Investigation of Bitemark Distortion in a Cadaver Model*

Abstract: Knowledge of distortional properties of skin is important in bitemark analysis. Thus, the response of skin to stress from bites was investigated. Four sets of models were created from the dentition of one individual. Anterior teeth were systematically removed to vary contact surface area. A biting apparatus was constructed with an integrated load cell. Forty‐six bites were created perpendicular to Langer lines on six cadavers. Rate of force application and bite pressure were controlled. Metric/angular measurement and hollow volume overlays were employed. Distortion produced by each dentition was calculated and assessed. Results showed that as teeth impressed loose tissue, mesial/distal distance increased, angles of rotation flattened, and inter‐canine distance lengthened. An opposite effect was seen in tight tissue. When the surface area of the dentition was reduced, a mixture of these effects was observed. Conclusions indicated that stiffness of the tissue was the most important variable in bitemark distortion.     

A Method for Estimating Sex Using Metric Analysis of the Scapula*

Abstract: The most accurate and precise methods for the assessment of age and stature often require knowledge of sex. Thus, being able to correctly identify sex from skeletal remains is critical in the forensic context. The presence of the os coxae or skull can never be guaranteed, making the development of reliable methods of sex estimation using other skeletal elements necessary. Using a 724 individual calibration sample from the Hamann‐Todd collection, this study identifies sexual dimorphism in the human scapula, and presents a new five‐variable discriminant function for sex estimation. The overall accuracy of this method proved to be 95.7% on the cross‐validated calibration sample, 92.5% on an 80 individual test sample from the Hamann‐Todd collection, and 84.4% on a 32 individual test sample from the skeletal collection of the Wichita State University Biological Anthropology Laboratory. Additionally, a slightly less accurate two‐variable model was developed and has cross‐validated accuracy of 91.3%.     

Recovery of Latent Fingerprints and DNA on Human Skin*

Abstract: The project “Latent Fingerprints and DNA on Human Skin” was the first systematic research in Europe dealing with detection of fingerprints and DNA left by offenders on the skin of corpses. One thousand samples gave results that allow general statements on the materials and methods used. The tests were carried out according to a uniform trial structure. Fingerprints were deposited by natural donors on corpses. The latent fingerprints were treated with magnetic powder or black fingerprint powder. Afterward, they were lifted with silicone casting material (Isomark^®) or gelatine foil. All lifts were swabbed to recover DNA. It was possible to visualize comparable and identifiable fingerprints on the skin of corpses (16%). In the same categories, magnetic powder (18.4%) yielded better results than black fingerprint powder (13.6%). The number of comparable and identifiable fingerprints decreased on the lifts (12.7%). Isomark^® (14.9%) was the better lifting material in comparison with gelatine foil (10.1%). In one‐third of the samples, DNA could be extracted from the powdered and lifted latents. Black fingerprint powder delivered the better result with a rate of 2.2% for full DNA profiles and profiles useful for exclusion in comparison with 1.8% for the magnetic powder traces. Isomark^® (3.1%) yielded better results than gelatine foil (0.6%).     

Anthropological and Radiographic Comparison of Antemortem Surgical Records for Identification of Skeletal Remains*

Abstract: This case review illustrates the important contributions of forensic archeological methods and forensic anthropological analysis to the identification of found skeletal remains. After reassociation of skeletal remains found in two locations, anthropological analysis provided the basis for a presumptive identification and a request for antemortem medical records. Partial DNA profiles were supportive but not conclusive and antemortem dental records were not available. Comparison of antemortem traumas, skeletal morphology, and surgical artifacts with antemortem radiographs and surgical records led to positive identification of an individual missing for almost a decade.