Superimposition

forensic medicine, photo and video superimposition, forensic identikit, facial composite

1. Superimposition & Identikit Najihah binti M ohd Y usri 064

2. It is a technique where a post mortem record is placed over a comparable antemortem record for comparison. Skull Superimposition 1. SUPERIMPOSITION

3. Technologically, skull-photo superimposition have passed through two phases : Photographic superimposition Video superimposition

4. Photographic The antemortem photograph is enlarged to “life size” and make as transparent. The skull is adjusted in such a way that the inclination and orientation are the same as that of the head in the photograph. # The complete skull is required to obtain positive identification.

5. The anatomical landmarks compared for a positive match include : External auditory meatus Orbits Anterior nasal spine Chin point Angles of the mandible Zygomatic processes # This test only can help in exclusion rather than conclusion.

6. Disadvantages : Slight change in the enlargement of the antemortem photograph or a slight change in the angulation of the skull can lead to mismatch. # These problems can be avoided by the use of video superimposition technique.

7. Video Superimposition Skull Antemortem photograph 2 colour video camera A video image mixing device A TV monitor A videotape recorder

8. The skull is first filmed with video camera 1 and reproduced on the TV monitor. The facial photograph is then reproduced on the TV monitor using video camera 2. The individual video signals from each camera are fed into a vision mixer so that a variety of function, like horizontal & vertical wiping, superimposition & negative simulation can be done. By adjusting the mixer, the video picture of the antemortem photograph can be enlarged based on the visibility of teeth / vertical facial height.

9. Advantages : immediate results can be videotaped for court purposes

10. 2. IDENTIKIT ( facial composite ) G raphical representation of an eyewitness's memory of a face, as recorded by a composite artist. Uses : Identifying the suspect in a wanted poster. Additional evidence against a suspect. Warning vulnerable population against serial offenders.

11. References Textbook of forensic medicine and toxicology, 16 th edition, editor VV Pillay . http :// what-when-how.com/forensic-sciences/skull-photo-superimposition/ THANK YOU 