1 / 35

The Reliability of CCTV as Forensic Evidence.

The Reliability of CCTV as Forensic Evidence. Glenn Porter School of Natural Sciences University of Western Sydney. Presented at the Expert Evidence Conference Canberra February 2011 Organised by the National Judicial College of Australia and the ANU College of Law. What is CCTV?.

asher-ellison
Download Presentation

The Reliability of CCTV as Forensic Evidence.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Reliability of CCTV as Forensic Evidence. Glenn Porter School of Natural Sciences University of Western Sydney Presented at the Expert Evidence Conference Canberra February 2011 Organised by the National Judicial College of Australia and the ANU College of Law

  2. What is CCTV? • Closed Circuit TeleVision. • Provides electronic surveillance. • Analogue or digital systems. • Monitored or non-monitored; static or PTZ (pan, tilt or zoom); covert or overt. Image sourced from; http://homesecuritysystem-10.com

  3. Benefits....... • Security. • Crime prevention (?) Image sourced from; www.hfs-info.com

  4. Benefits....... • Forensic Intelligence.... • Provides vision of the event for reconstruction. • Crime scene investigation (point of entry & exit, identify key scene areas and items of interest). • Circumstantial evidence – clothing, bags etc. • Track suspects and/or victims movement prior and after event. • Trace identifiable items such as vehicle registration plates.

  5. Benefits....... Images sourced from; www.thamesvalley.police.uk Images sourced from; www.thamesvalley.police.uk

  6. Benefits....... • Recognition evidence. • Identification by persons known to the accused. • Identification (?) Image sourced from: http://interestingphoto.net/

  7. Individualisation Methods • Distinctive markings (scars, birth marks, freckles, tattoos). • Facial asymmetry. • Morphological comparison. • Photo-anthropometry.

  8. Distinctive Markings • Scars. • Moles. • Freckles. • Tattoos. • Anatomical peculiarities. Image sourced from; http://0.tqn.com/d/weirdnews

  9. Facial Asymmetry Right + Right Left + Left

  10. Facial Asymmetry Right + Right Left + Left

  11. Morphological Comparison Side-by-side method.

  12. Morphological Comparison Photosuperimposition. Cattaneo C., (2007) “Forensic anthropology: developments of a classical discipline in the new millennium” Forensic Science International, 165: 185-193

  13. Morphology Issues

  14. Exemplar Images at 0.5m, 1.0m and 2.0m Questioned Imageat 0.5m Images by Jodie Green Exemplar Images at 3.0m, 4.0m and 6.0m

  15. Graph & Data by Jodie Green

  16. Photo-anthropometry Image sourced from; http://slince.iespana.es

  17. Bertillonage • Early identification method developed in the 19th century by Alphonse Bertillon (1853-1914). • Comprised of 11 different physical measurements from anatomical features. • Considered as an unique method of identification with a 411 or 4,191,304 to 1 probability. Source; Bertillon A. (1896) “Signaletic Instructions: Including the Theory and Practice of Anthropometrical Identification” The Werner Company

  18. Will & William West (1903) • Bertillon’s anatomical identification system failed because; • In 1903 two unrelated prisoners in the Leavenworth Prison (USA) were found to have identical anthropometric measurements. • Found not to be unique for identification of anatomical features. Source; Nickell J., (1994) “Camera Clues: A Handbook for Photographic Investigation” The University Press of Kentucky

  19. Technical Issues • Image resolution (optical resolution, digital resolution, screen height of subject). • System compatibility. • File acquisition – native file or copy. • Lighting. • Frame rate. • Image dimensional integrity (camera placement, optical aberrations, image perspective). • Chain of custody of image.

  20. Poor Resolution

  21. Dimensional Integrity

  22. Dimensional Integrity – Body Shape -40% Lens Distortion +40% Lens Distortion No Lens Distortion

  23. Rectilinear distortion: body shape changes with camera height, distance and the relationship of both.

  24. Similarities • NSW CCA – Tang. • Pseudo identification evidence. • Predominately based on body shape. • ‘Strong anatomical similarities’. • Evidence expression always based on similarities of the individual – no explanation regarding how many other individuals would share same physical appearance. • s137 .................

  25. What Next.........? • Who should examine CCTV evidence? • Photographic or imaging science experts. • Anatomists. • Photogrammetrists. • Pattern recognition experts. • Determine technical parameters required for forensic science examination of images. • Develop camera placement strategies for a range of applications including identification.

  26. What Next.........? • Gain a better understanding of visual culture influences. • Visual narratives. • Intertextuality. • Theoretical frameworks when images are used as forensic evidence and photointerpretation. • Determine conceptual and pragmatic parameters of identification of individuals using images........if any.

  27. Edmond G., Biber K., Kemp R., Porter G., (2009) “Laws Looking Glass: Expert Identification Evidence Derived from Photographic and Video Images” Current Issues in Criminal Justice, 20:3 337-377.

  28. Porter G., (2011) “A New Theoretical Framework Regarding the Application and Reliability of Photographic Evidence.” International Journal of Evidence & Proof, 15:1 26-61.

More Related