The Role of the Human Ear in the process of Forensic Identification

Transcription

1 The Role of the Human Ear in the process of Forensic Identification By Ali Abbas A thesis submitted in partial fulfilment of the requirement for the degree of BMedSci Supervisor Professor Guy Rutty Division of Forensic Pathology, Department of Pathology, Robert Kilpatrick Clinical Science Building Leicester Royal Infirmary Leicester

2 May 2003

3 Contents Chapter 1 Introduction. 1.1 History of prints in forensic identification The aim of the study Why choose the ear? Anatomy and development of the human ear Embryology of the external ear Growth of the ear Literature search Current research on the ear Measuring the ear Limitations of current knowledge Aims of the study 16 Chapter 2 Method. 2.1 Setting up the project Ethics Selection of volunteers and consent Equipment The apparatus Data collection and storage Photographing ears Printing ears 23 Chapter 3 Designing a photographic ear database. 3.1 The computer software 25

4 3.2 Standardising photographic analysis Positioning the grid Constructing a photographic ear database Searching for an image Results Conclusion 37 Chapter 4 Designing a database of earprints. 4.1 Print analysis Selecting a standardised method of marking prints Positioning the grid Method Results Conclusion 50 Chapter 5 Manual methods. 5.1 Sample selection Manual methods Method Method Results Conclusion 59 Chapter 6 Designing an ideal ear. 6.1 Method Results Conclusion 68

5 Chapter 7 Distribution of piercings. 7.1 Method Results Conclusion 71 Chapter 8 Final discussion. 73 References 78 Appendix A Setting up the project I B Data collection and manual analysis II C Statistical methods III

6 Figures and Tables Chapter 1 Figure 1.1 CCTV camera used to capture ear images. 3 Figure 1.2 Anatomy of the ear. 5 Figure 1.3 Brachial arches that form the ear. 6 Figure 1.4 Formation of the ear. 6 Figure 1.5 Developmental abnormalities of the ear. 7 Figure 1.6 Developmental timeline of the ear. 8 Figure 1.7 Anthropological measurements used by Bertilloni. 10 Figure 1.8 Earlobe variation. 12 Figure 1.9 Measuring method designed by Iannarelli. 13 Figure 1.10 Measuring method designed by M. Alexander. 13 Chapter 2 Figure 2.1 Apparatus used to capture photographs of ears. 20 Figure 2.2 Comparison betweenan ear photograph and an earprint. 24 Chapter 3 Figure 3.1 An example of the lattice generated by the computer software. 25 Figure 3.2 An annotated diagram of Iannarelli s grid. 27 Figure 3.3 The computerised form used to record the demographic data. 29 Figure 3.4 The sequence used to construct a photographic ear database. 30 Figure 3.5 An example of a search outcome for an ear photograph. 32

7 Table 3.1 Ethnic diversity of the volunteers used in the study. 33 Table 3.2 Distribution of photographic matches. 34 Table 3.3 The results of a search conducted on a whole ear photograph. 35 Table 3.4 The results of a search conducted on a partial ear photograph. 36 Chapter 4 Figure 4.1 Grid used to mark earprints. 43 Figure 4.2 The method used to position the grid on earprints. 44 Figure 4.3 The sequence used to construct a database of earprints. 45 Figure 4.4 An example of a search outcome for earprints. 47 Table 4.1 The results of a search conducted on a whole earprint. 48 Table 4.2 The results of a search conducted on a partial earprint. 49 Chapter 5 Figure 5.1 Manual methods used to mark ear photographs. 54 Figure 5.2 Anatomical points used to position Iannaralli s grid. 56 Figure 5.3 Measurements taken using Iannarelli s grid. 56 Figure 5.4 An example of the table used to record Iannarelli s measurements. 57 Table 5.1 Results comparing the manual methods with the computer method. 58 Chapter 6

8 Figure 6.1 Extra measurements recorded using Iannarelli s grid. 62 Figure 6.2 Ideal male right ear. 63 Figure 6.3 Ideal male left ear. 63 Figure 6.4 Ideal female right ear. 64 Figure 6.5 Ideal female left ear. 64 Figure 6.6 Significant differences between right and left male ears. 65 Figure 6.7 Significant differences between right and left female ears. 65 Figure 6.8 Significant differences between right male and right female ears. 66 Figure 6.9 Significant differences between left male and left female ear. 66 Table 6.1 T-test comparing male right ear with male left ear. 65 Table 6.2 T-test comparing female right ear with female left ear. 65 Table 6.3 T-test comparing male right ear with female right ear. 66 Table 6.4 T-test comparing male left ear with female left ear. 66 Chapter 7 Figure 7.1 The distribution of piercings on each ear. 71 Chapter 8 Figure 8.1 Facial reconstruction techniques. 75

9 Abstract The ear was first used to identify individuals in the late 19 th century as part of 11 anthropometric measurements of the human body that included measuring ear length and width. However, despite the fact that earprints are found in 15% of crime scenes, research in this field has been very limited since the advent and success of fingerprinting in the early 20 th century. Although earprint identification has been used in criminal trials both within the UK and abroad, to date a standardised computer method for earprint and ear image recognition does not exist. This project has managed to design the first computerised system for earprints and image identification, using data collected from 400 volunteers and a novel piece of software designed by K9 Forensic Services Ltd, (Northampton, UK). Previously published manual methods for ear image identification were critically reviewed and their effectiveness in constructing a database and identifying a match was tested against the computerised system. The data generated in the project was also used to assess differences between right and left ears within each gender, and enabled the design of an ideal ear for each group for use in anthropological identification. Finally, the distribution of piercings on the right and left ears was also assessed and

10 helped to identify another feature that may be of use in ear identification. The project has produced, to my knowledge, the first computerised earprint and ear photograph recognition system in the world, and has managed to design the first published method for earprint identification.