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

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

Contents

Chapter 1 – Introduction.

1.1 History of prints in forensic identification 1

1.2 The aim of the study 2

1.3 Why choose the ear? 2

1.4 Anatomy and development of the human ear 4

1.5 Embryology of the external ear 5

1.6 Growth of the ear 8

1.7 Literature search 9

1.8 Current research on the ear 10

1.9 Measuring the ear 12

1.10 Limitations of current knowledge 13

1.11 Aims of the study 16

Chapter 2 – Method.

2.1 Setting up the project 17

2.2 Ethics 17

2.3 Selection of volunteers and consent 17

2.4 Equipment 18

2.5 The apparatus 19

2.6 Data collection and storage 21

2.7 Photographing ears 22

2.8 Printing ears 23

Chapter 3 – Designing a photographic ear database.

3.2 Standardising photographic analysis 26

3.3 Positioning the grid 28

3.4 Constructing a photographic ear database 28

3.5 Searching for an image 32

3.6 Results 33

3.7 Conclusion 37

Chapter 4 – Designing a database of earprints.

4.1 Print analysis 40

4.2 Selecting a standardised method of marking prints 40

4.3 Positioning the grid 43

4.4 Method 44

4.5 Results 46

4.6 Conclusion 50

Chapter 5 – Manual methods.

5.1 Sample selection 52 5.2 Manual methods 53 5.2.1 Method 1 5.2.2 Method 2 55 5.3 Results 58 5.4 Conclusion 59

Chapter 6 – Designing an ideal ear.

6.1 Method 61

6.2 Results 62

Chapter 7 – Distribution of piercings.

7.1 Method 70

7.2 Results 70

7.3 Conclusion 71

Chapter 8 – Final discussion.

References

Appendix A – Setting up the project

B – Data collection and manual analysis

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

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

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

Abstract

The ear was first used to identify individuals in the late 19th 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

20th 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

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