SUBMITTED BY- Palak Saket M.Sc. 1st semester Forensic Science Department

Govt.Holkar Science College (M.P.)

SKULL SUPERIMPOSITION TECHNIQUE

ACKNOWLEDGEMENT

I am extremely thankful to my department of forensic of Holkar

Science College, Indore.

I express my sincere appreciation to all the teachers for guiding and

supporting me.

OVERVIEW IntroductionHistoryPhotographic superimpositionVideo superimpositionComputer assisted superimposition3D superimpositionCase studyConclusion

INTRODUCTION

It is one of the parameter for personal identification.

Superimposition is a technique applied to determine whether the skull is that of the person in photograph.

The skull photograph technique is considered to be the facial reconstruction.

In this it attempts to supply a facial photograph for a discovered unknown skull.

HISTORYThis technique was first applied by Glaister and Brash in 1935.

Ruxton case was solved by them.

Two skulls were found with the query of which one is Mrs. Ruxton’s skull.

Superimposition technique solved the query.

ARRANGEMENT OF PHOTOGRAPH

APPLICATION OF SUPERIMPOSITION

TECNIQUE

IDENTIFICATION

BASIC STEPS FOR PERSONAL IDENTIFICATION THROUGH SKULL SUPERIMPOSITION TECHNIQUE

PHOTOGRAPHIC SUPERIMPOSITION TECNIQUE

o This technique was developed in the mid 1930s.

o Negative of the recent photograph is obtained.

o The negative is placed under the ground glass of camera and salient features of face are marked out carefully.

o A 1inch scale is placed on the forehead of skull on a suitable skull rest.

o The skull is then photographed on quarter size cut film.

o The negative of the photograph and the skull are superimposed by aligning the characteristic points in the negative.

THE FOLLOWING PARTS ARE THEN COMPARED The eyes within the

orbital plate. The nasion. The prosthion in the

central line. The nasal spine in the

centre which is a little above the tip of nose.

The lower border of upper jaw.

The zygomas below the eyes.

Supraorbital ridges. Angle of jaw. External auditory meatus.

Teeth.

VIDEO SUPERIMPOSITION In the later half of 1970s, the video superimposition

technique has been widely used in the field of forensic anthropology.

Skull is placed on a rotatable stand and photograph is also fixed under other camera.

Images of skull and photograph are projected on a

monitor.

By series of blending, fading & sweeping images of skull & photograph are superimposed.

All the anatomical landmarks are compared.

COMPUTER ASSISTED SUPERIMPOSITION

• The skull and facial photograph are digitized using a computer.

• The two images are compared morphologically.

• Establishing the scale for digitized skull is performed by converting the actual measurements between the landmarks into the number of pixels on monitor.

• Anatomical relationships are evaluated by wiping, fade in and fade out.

3D CRANIOFACIAL SUPERIMPOSITION

CASE STUDYSHEENA BORA CASE-

On 24th April 2012 Sheena Bora killed by her mother Indrani Mukherjee and her step father Sanjeev Khanna. Their former driver Shyamavar Rai was also involved. On 23rd may 2012 a decomposed body discovered from the forest of Raigad district . On August 2015 the skull of the body found and Sheena’s photo matched with the help of digital superimposition and found positive results revealed the identification of skull that it is of Sheena Bora’s.

ACCURACY

The most well-known study to assess the reliability of superimposition was done in 1994 by Austin- Smith and Maples. These authors used three skulls of known identity and compared them to 97 lateral and 98 anterior view photographs. It was found that the chances of having a false positive identification using lateral shots were 9.6%and using anterior shots was 8.5%. However, when using the lateral and anterior shots combined,the chances of a false positive were reduced to 0.6%. A study conducted in India in 2001established a 91% positive identification rate.

CONCLUSION

Skull superimposition is reliable and an accurate technique for identification and recognition in forensic anthropology.

Helpful in solving many cases.

This method has been developed to try to speed up and automate the traditional method used by forensic doctors making possible the comparison of a large number of photos with a skull with little user intervention.

Nowadays, this technique is in validation process

THANKYOU