Kalagate Imagery Bureau

Report by Geoffrey John Oxlee

Specialisation: FORENSIC IMAGERY ANALYST

Comparison Between Two Persons Called Man A and Man B

Introduction

I am Geoffrey John Oxlee, a senior imagery analyst with the Kalagate Imagery Bureau. I was asked to look at 8 photographs, each of which nominated a person as the subject. I was then asked to answer 3 questions relating to these pictures.

The photographs were analyzed using an Abrams stereoscope and a precision Bausch and Lomb measuring magnifier. Because of the lack of detail on some of the photographs, I was only able to make a small number of photogrammetric measurement comparisons. The results of the photogrammetry are shown at Annex A.

The Questions

Question 1

Are photographs N1-GO to N6-GO the same person or a different person?

Answer

The photographs are of the same person. There is an overwhelming similarity in the major facial features to the extent that only an identical twin would share. Hereinafter this person is called Man A.

Question 2

Are the photographs N7-GO and N8-GO the same or a different person?

Answer

These photographs are not the originals and appear to have undergone digital processing. The photographs are of the same person. The facial features that can be seen are the same, and the facial hair and clothing are identical. Hereinafter this person is called Man B.

Question 3

Can it be determined from the photographs that Man A and Man B are one and the same or not one and the same?

Answer

Neither can be determined. There are insufficient details of the features of Man B to be able to make a safe comparison. The top of the face of Man B is hidden by his hat, and the lower half is covered by facial hair. There are some similarities, such as the general face shape and the general shape of the nose. However, these similarities will be shared by many in the population.

Question 4

Would it be wise to use photographs N7-GO and N8-GO alone to make a positive identification?

Answer

No, it would be both unwise and forensically unsafe to do so. There is insufficient facial detail and an insufficient number of measurements are possible.

ANNEX A PHOTOGRAMMETRIC WORK

The photographs used were N3-GO and N8-GO. These are of different scales. However, if ratios between distances are used, this obviates the need for rescaling. In each case, 10 measurements of distances were made, and the mathematical average was used to minimize measurement errors.

The results

Man A

• Nasion (Top of nose): 0mm = 0%
• Pronasale (nose tip): 6.5 mm = 70.6%
• Stomion (centre mouth): 9.2mm = 100%
• Ears: 7.4 mm = 80.4%
• Interoccular: 8.6mm = 93.4%

Man B

• Nasion: 0mm = 0
• Pronasale: 3.8 mm = 69.1%
• Stomion: 5.5 mm = 100%
• Ears: 4.0mm = 72.7%
• Interoccular: 5.1mm = 92.7%

From these results, it can be seen that within the mathematical tolerances, the two persons are similar in most measurements. The exception is the proportional size of the ears. Although this may tend to cast doubt that Man A and Man B are the same, one difference of this magnitude is insufficient to be sure that they are different.