Forensic Science

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Forensic Science FORENSIC SCIENCE ‘AN ART OF FACIAL RECONSTRUCTION’

Presented by: Asmita A.Inamdar USN: 2GI06MCA08 M.C.A 2nd SEM And Veena S.Mithare USN: 2GI06MCA58 M.C.A 2nd SEM

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Forensic Science
ABSTRACT Facial reconstruction for postmortem identification of humans from their skeletal remains is a challenging and fascinating part of forensic art. The former look of a face can be approximated by predicting and modeling the layers of tissue on the skull. This work is as of today carried out solely by physical sculpting with clay, where experienced artists invest up to hundreds of hours to craft a reconstructed face model. Remarkably, one of the most popula r tissue reconstruction methods bears many resemblances with surface fitting techniques, thus suggesting the possibility of a transfer of the manual approach to the computer. In this paper, we present a facial reconstruction approach that fits an anatomy-based virtual head model, incorporating skin and muscles, to a scanned skull using the data on skull / tissue relationships. The approach has many advantages over the traditional process: a reconstruction can be completed in about an hour from acquired skull data; also, variations such as a slender or a more obese build of the modeled individual are easily created. Last not least, by matching not only skin geometry but also virtual muscle layers, head model is generated that can be used to form facial expressions.

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Forensic Science INDEX

Sl.no 1. 2. 3. 4. Definition History Types of identification

Contents

Page no. 01 01- 02 02- 03 03- 05

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Types of reconstructions 4.1 Two-dimensional reconstructions 4.2 Three-dimensional reconstructions 4.3 Superimposition Technique for creating 3-D reconstruction 5.1 3-D clay reconstructions 5.2 computerized 3-D facial reconstruction Problems with facial reconstruction 6.1 Insufficient tissue thickness data 6.2 Lack of methodological standardization 6.3 Subjectivity Facial reconstructions and the media Future developments Subdivisions of forensic science Indian institutions offering forensic science Conclusion References

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Forensic Science DEFINITION – Forensic facial reconstruction (or forensic facial approximation) is the process of recreating the face of an unidentified individual from their skeletal remains through an amalgamation of artistry, forensic science, anthropology, osteology, and anatomy. It is easily the most subjective - as well as one of the most controversial - techniques in the field of forensic anthropology. Despite this controversy, facial reconstruction has proved successful frequently enough that research and methodological developments continue to be advanced.

1. HISTORYWelcker (1883) and His (1895) were the first to reproduce three-dimensional facial approximations from cranial remains. Most sources, however, acknowledge His as the forerunner in advancing the technique. His also produced the first data on average facial tissue thickness followed by Kollmann and Buchly who later collected additional data and compiled tables that are still referenced in most laboratories working on facial reproductions today. Facial reconstruction originated in two of the four major subfields of anthropology. In biological anthropology, they were used to approximate the appearance of early hominid forms, while in archaeology they were used to validate the remains of historic figures. In 1964, Gerasimov was probably the first to attempt paleo-anthropological facial reconstruction to estimate the appearance of ancient peoples.

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Forensic Science Although students of Gerasimov later used his techniques to aid in criminal investigations, it was Wilton M. Krogman who popularized facial reconstruction’s application to the forensic field. Krogman presented his method for facial reconstruction in his 1962 book, detailing his method for approximation. Others who helped popularize three-dimensional facial reconstruction include Cherry (1977), Angel (1977), Gatliff (1984), Snow (1979), and Iscan (1986).

2. TYPES OF IDENTIFICATION There are two types of identification in forensic anthropology: circumstantial and positive. Circumstantial identificationIt is established when an individual fits the biological profile of a set of skeletal remains. This type of identification does not prove or verify identity because any number of individuals may fit the same biological description.

3.2 Positive identificationIt one of the foremost goals of forensic science, is established when a unique set of biological characteristics of an individual are matched with a set of skeletal remains. This type of identification requires the skeletal remains to correspond with medical or dental records, unique ante mortem wounds or pathologies, DNA analysis, and still other means. Facial reconstruction presents investigators and family members involved in criminal cases M.C.A 2nd Semester 5

Forensic Science concerning unidentified remains with a unique alternative when all other identification techniques have failed. Facial approximations often provide the stimuli that eventually lead to the positive identification of remains.

4. TYPES OF RECONSTRUCTIONS There are two main methods used in forensic facial approximation: twodimensional and three-dimensional. 4.1 Two-dimensional reconstructionsTwo-dimensional facial reconstructions are hand-drawn portraits based on radiographs, ante mortem photographs, and the skull. This method usually requires the collaboration of an artist and a forensic anthropologist. Recently developed, the F.A.C.E. and C.A.R.E.S. computer software programs quickly produce two-dimensional facial approximations that can be edited and manipulated with relative ease. These programs help speed the reconstruction process and allow subtle variations to be applied to the drawing.

Figure 1- 2-D facial reconstruction.

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Forensic Science 4.1 Three-dimensional reconstructionsThree-dimensional facial reconstructions are either: 1) sculptures (made from casts of cranial remains) created with modeling clay and other materials or 2) high-resolution, three-dimensional computer images. Like twodimensional reconstructions, three-dimensional reconstructions usually require both an artist and a forensic anthropologist. Computer programs create three-dimensional reconstructions by manipulating scanned photographs of the unidentified cranial remains, stock photographs of facial features, and other available reconstructions. These computer approximations are usually most effective in victim identification because they do not appear too picturesque or too artificial.

Figure 2- 3-D facial reconstruction.

4.2 SuperimpositionSuperimposition is a technique that is sometimes included among the methods of forensic facial reconstruction. It is not always included as a technique because investigators must already have some kind of knowledge M.C.A 2nd Semester 7

Forensic Science about the identity of the skeletal remains with which they are dealing (as opposed to 2D and 3D reconstructions, when the identity of the ske letal remains is generally completely unknown). Forensic superimpositions are created by superimposing a photograph of an individual suspected of belonging to the unidentified skeletal remains over an X-ray of the unidentified skull. If the skull and the photograph are of the same individual, then the anatomical features of the face should align accurately.

5. TECHNIQUE FOR CREATING 3-D FACIAL RECONSTRUCTION – 5.1 3-D clay reconstructionsWhen skeletal remains are found, and the victim remains unidentified after traditional means of identification fail, investigators may call upon the forensic artist to utilize the three-dimensional facial reconstruction technique. The threedimensional process is initiated by placing the skull on a workable stand, where the skull can easily be tilted and turned in all directions. The skull must be positioned in the Frankfort Horizontal position. By utilizing proper tissue depth data determined by race, gender, and age. Artificial eyes are placed in the skull’s eye sockets, centered and at the proper depth. The tissue markers are glued directly onto the skull. Clay will be systematically applied directly on the skull, following the skull's contours; paying strict attention to the applied tissue markers. Various measurements are made, and logged, to determine nose thickness/length, mouth thickness/width, and eye placement. Information such as geographic location of where the deceased lived, his or her lifestyle, and the M.C.A 2nd Semester 8

Forensic Science various information provided to the artist by the Forensic Anthropologist and other professionals, is heavily relied upon when completing the reconstruction. Hair is accomplished by means of a wig, or by applying clay to represent hair. Various items (props), such as glasses, clothing, hats, etc. may be applied to better accentuate the features of the individual. Upon completion, the sculpture is photographed. All procedures are documented and working notes collected. When executed properly, this technique is proven to have a high success rate.

Frontal View of Skull Figure 3

Completed Reconstruction Figure 4

Reconstruction Colorized Figure 5

5.2 Computerized 3-D Facial ReconstructionMost recently, computerized methods for 3D facial reconstruction have been developed (Ubelaker and O'Donnell 1992, Vanezis et al. 1989, Shahrom et al. 1996, Miyasaka et al. 1995). These methods employ computer programs to transform laser-scanned 3D skull images into faces. Although the results are more reproducible than sculpted reconstructions, some subjectivity can remain in the 'pegging' of a composite facial image onto the digitized skull matrix. The use of M.C.A 2nd Semester 9

Forensic Science such a standardized image will reduce the influence of the individual shape of each skull, which is after all fundamental to the person's appearance. Computerized methods may be repeatable, fast and precise, but as long as they employ the old data, the quality of the reconstruction will be undermined. Here a Cyberware 3030 RGB color laser scanner and Silicon Graphics Indy™ computer to capture 3D images of the skull. As the platform rotates (Figure 5) a 'wire frame' matrix is generated (Figure 6). Computed tomography (CT) scanning permits more accurate measurement of tissue depths (Figure 7). Large samples of tissue depth measurements can be collected, with associated attributes of age, sex, build and, where appropriate, ethnic group. A pilot study on the collection of tissue depth measurements from CT scans has been carried out by one of our team (Nelson 1996). Digitized images of facial features not predicted by the skull contours (nose, eyes and mouth) must be added by separate means to generate a wire frame face (Figure 8), onto which color and texture can subsequently be rendered (Figure 9). If necessary, a skull can be reconstructed 'virtually' from the separately scanned parts.

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

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Forensic Science 6. PROBLEMS WITH FACIAL RECONSTRUCTION6.1 Insufficient tissue thickness dataThere are multiple outstanding problems associated with forensic facial reconstruction. The most pressing issue relates to the data used to average facial tissue thickness. The data available to forensic artists are still very limited in ranges of ages, sexes, and body builds. This disparity greatly affects the accuracy of reconstructions. Until this data is expanded, the likelihood of producing the most accurate reconstruction possible is largely limited.

6.2 Lack of methodological standardizationA second problem is the lack of a methodological standardization in approximating facial features and individuating characteristics. Forensic anthropologists and artists have published individual techniques used in their own practices. However, a single, official method for reconstructing the face has yet to be recognized. This also presents major setback in facial approximation because facial features like the eyes and nose and individuating characteristics like hairstyle - the features most likely to be recalled by witnesses - lack a standard way of being reconstructed. Without consistency and a standard method for approximating these features, it will remain very difficult for forensic reconstruction to earn wide recognition as a legitimate form of forensic identification.

6.3 SubjectivityM.C.A 2nd Semester 11

Forensic Science Reconstructions only reveal the type of face a person may have exhibited because of artistic subjectivity. The position and general shape of the main facial features are mostly accurate because they are greatly determined by the skull, but subtle details like certain wrinkles, birthmarks, skin folds, the shape of the nose and ears, etc, are unavoidably speculative because skeletal remains leave no evidence of their appearance. The success of reconstruction depends as much upon the circumstances pertaining to the subject under investigation as it does upon the accuracy of the technique.

7. FACIAL RECONSTRUCTION AND THE MEDIA The facial reconstruction of Tutankhamen as shown on the cover of National Geographic in 2005.

Due to the recent rise in popularity of television shows (e.g. CSI: Crime Scene Investigation, CSI: Miami, CSI: NY, NCIS, Bones, and the UK program M.C.A 2nd Semester 12

Forensic Science Meet the Ancestors) and feature films concerned with criminal investigations, forensics, and law enforcement, the presence of forensic facial reconstructions in the entertainment industry and the media has also increased.. In reality, facial reconstructions are widely used as a last resort to stimulate the possibility of identifying a victim. Interest in discovering and identifying “lost” and/or significant historical figures has also increased the presence of forensic facial reconstruction among the public consciousness. For example, the facial reconstruction of Egypt’s King Tut made the June 2005 cover of National Geographic Magazine. Casdon Toys has produced a line of at-home facial reconstruction toys featuring Julius Caesar, King Tut, Queen Nefertiti, and Neanderthal Man. The popular CSI: Crime Scene Investigation television show has also produced an at- home facial reconstruction kit.

8. FUTURE DEVELOPMENTSCurrently, data collection from CT scans is a laborious and timeconsuming process of amassing a series of point-to-point measurements. The automated capture of 3D data from CT scans is an imminent proposition, but will not be cost effective for facial reconstruction in the near future. Methods for ageing a reconstruction or for making comparisons with digitized missing person databases are also far off. It has been suggested that an eventual understanding of the developmental genetics of facial growth may allow forensic or ancient DNA to be used to inform reconstructions. This imaginative idea somewhat downplays the importance of epigenetic factors in physiological development – and the M.C.A 2nd Semester 13

Forensic Science influence of ageing, build and a plethora of environmental influences upon one's appearance! Research on the psychology of face recognition will be applicable, and portable laser scanning equipment is shortly to be made available – raising the possibility that computerized facial reconstruction could be used in sensitive human rights work in the field.

9. SUBDIVISIONS OF FORENSIC SCIENCE1. Forensic accounting is the study and interpretation of accounting evidence. 2. Forensic anthropology is the application of physical anthropology in a legal setting, usually for the recovery and identification of skeletonized human remains. 3. Forensic archaeology 4. Forensic computing 5. Forensic economics is the study and interpretation of economic damage evidence to include present day calculations of lost earnings and benefits, the lost value of a business, lost business profits, lost value of household service, replacement labor costs and future medical care costs. 6. Forensic engineering studies the causes of failure of devices and structures. 7. Forensic epistemology deals with philosophical knowledge in a legal setting, typically for understanding behavior of states. 8. Forensic linguistics deals with anything in the legal system that requires linguistic expertise. 9. Forensic Medicine M.C.A 2nd Semester 14

Forensic Science 10. Forensic psychology and forensic psychiatry deal with the legal aspects of human behavior. 11. Forensic science using science to create an argument in places such as court. 12. Forensic biology performs serological and DNA analysis of physiological fluids for the purpose of identification and individualization. 13. Forensic serology is the application of the study of blood, semen, saliva and other body fluids to legal matters. 14. Digital forensics deals with the digital evidence (e.g. e-mail, photos stored on a computer).

10. INDIAN INSTITUTIONS OFFERING FORENSIC SCIENCE1. Dr. Harisingh Gour University, Sagar, MP 2. University of Madras (Chennai), Chennai 3. University of Mysore, Karnataka 4. Osmania Universty, Hyderabad 5.Lok Nayak Jayaprakash Narayan National Institute of Criminology and Forensic Science 6. School of Engineering and Applied Sciences (SEAS),(Rai University) 7.Bureau of Police Research & Development, Govt. of India, New Delhi

11. CONCLUSIONFacial reconstruction is destined to remain an art, albeit an increasingly informed one. Nevertheless, a forensic facial reconstruction has value in M.C.A 2nd Semester 15

Forensic Science potentially allowing the exclusion of a particular individual as the unidentified subject.

12. REFERENCES9.1 Reference to an internet source http://www.google.co.in/ http://en.wikipedia.org/wiki/Forensic_facial_reconstruction http://en.wikipedia.org/wiki/Forensic_identification http://en.wikipedia.org/wiki/Forensic http://www.forensicpage.com/new05.htm http://www.assemblage.group.shef.ac.uk/1/evison.html

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