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Merging Digital Photography With Crime Scene Investigations

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Merging Digital Photography With Crime Scene Investigations

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  1. Merging Digital PhotographyWith Crime Scene Investigations LVMPD Criminalistics Bureau

  2. Introduction • This training is designed to develop a foundation for the basics of digital photography, and the integration of digital photography into a law enforcement environment. • Students will leave this training with: 1) A fundamental understanding of how digital imaging works. 2) The ability to operate, and maintain a 35mm digital camera. 3) An understanding of policies and procedures related to the capture, transfer, storage, and output of digital images to keep the evidentiary integrity of images intact.

  3. A “Mega-Byte” of Digital History…

  4. 1951 • The first video tape recorder captured live images from television cameras by converting the information to electrical impulses (digital) and saving the information to magnetic tape.

  5. 1964 • First electronic photos of Mars. NASA, at the Jet Propulsion Lab in Pasadena, CA, received electronic signals from video cameras on board the Mariner (IV) spacecraft on its way to Mars. Although no CCD was used, much of the same technology was utilized in the development of the modern day CCD.

  6. 1970 • Bell Labs constructed the world’s first solid-state video camera using a CCD as the imaging device. This digital technology was applied to still cameras several years later. Complete CCD Assembly CCD Wafer

  7. 1971 THE FIRST EMAIL was sent. The person responsible for this was Ray Tomlinson, a computer engineer. Tomlinson was employed by Bolt Beranek and Newman, a company contracted by the US Defense Department to build ARPANET, the precursor to the internet.

  8. 1972 • In 1972, Texas Instruments patented a film-less electronic camera, the first company to do so.

  9. 1974 • The first astronomical image (100x100 pixels) was captured on CCD through an 8 inch telescope.

  10. 1975 • Kodak prototype still camera was designed with the world’s first known operational electronic CCD. The sensor captured a 100x100 pixel image and it required 23 seconds to record a single image onto a cassette tape

  11. 1981 • Sony released the Sony Mavica electronic still camera. This was the first commercial electronic still camera on the consumer market. Images were recorded onto a mini disc and then put into a video reader that was connected to a television monitor or color printer.

  12. 1984 • Canon conducted a trial of a professional color still camera (RC-701) and an analog transmitter at the LA Olympics. Images were transmitted back to Japan via phone lines. The camera used a 400 pixel CCD.

  13. 1985 • The Nikon SVC (Still Video Camera) prototype camera was unveiled. It had a 2/3 inch CCD of 300,000 pixels. It allowed the analog recording of 25 or 50 images on a small floppy disc of 2 inches.

  14. 1986 • Work was started to establish a standard method for representing photographic images in digital form. The group formed was ultimately called “Joint Photographic Experts Group” under the auspices of the International Organization for Standards (ISO), and the result is known as (JPEG).

  15. 1990 • The worlds first completely digital consumer camera was unveiled, the Dycam Model 1. It stored 32 images internally on 1MB RAM and only shot B/W.

  16. 1992 • In 1992 the Kodak DCS 200 was released. This camera was the first with a built in hard drive for image recording and was a 1.5 Megapixel camera. You could own this beauty for a mere $25,000.00.

  17. 1994 • Compact flash memory card first available on the market. It was introduced by SanDisk Corp. The first discs held 2-24 MB of data. It was the first solid state memory card designed that could retain data indefinitely without the use of a battery.

  18. …And On And On…

  19. Why Digital For Law Enforcement?

  20. With current technology, images are as good or better an traditional 35mm film.

  21. With current technology, images are as good or better than traditional 35mm film. • Images can be reviewed instantaneously at a scene for proper exposure, composition, content, etc.

  22. With current technology, images are as good or better an traditional 35mm film. • Images can be reviewed instantaneously at a scene for proper exposure, composition, content, etc. • Hundreds of images can be stored on a single memory card, eliminating the need for multiple rolls of film.

  23. With current technology, images are as good or better an traditional 35mm film. • Images can be reviewed instantaneously at a scene for proper exposure, composition, content, etc. • Hundreds of images can be stored on a single memory card, eliminating the need for multiple rolls of film. • Images are easily shared between law enforcement personnel and agencies through electronic means.

  24. With current technology, images are as good or better an traditional 35mm film. • Images can be reviewed instantaneously at a scene for proper exposure, composition, content, etc. • Hundreds of images can be stored on a single memory card, eliminating the need for multiple rolls of film. • Images are easily shared between law enforcement personnel and agencies through electronic means. • Film, chemicals, and photographic paper usage is dramatically reduced.

  25. With current technology, images are as good or better an traditional 35mm film. • Images can be reviewed instantaneously at a scene for proper exposure, composition, content, etc. • Hundreds of images can be stored on a single memory card, eliminating the need for multiple rolls of film. • Images are easily shared between law enforcement personnel and agencies through electronic means. • Film, chemicals, and photographic paper usage is dramatically reduced. • Storage space is reduced to nearly nothing.

  26. With current technology, images are as good or better an traditional 35mm film. • Images can be reviewed instantaneously at a scene for proper exposure, composition, content, etc. • Hundreds of images can be stored on a single memory card, eliminating the need for multiple rolls of film. • Images are easily shared between law enforcement personnel and agencies through electronic means. • Film, chemicals, and photographic paper usage is dramatically reduced. • Storage space is reduced to nearly nothing. • Images can be digitally tracked with an audit trail to authenticate chain of evidence

  27. The Courts View On Digital Imaging…

  28. TWO QUESTOINS...

  29. Got SOPs?

  30. Got SOPs? • 2) Can “Frye” Fly?

  31. If you can answer these two questions with a “YES”, chances are, you are going to be set in court.

  32. SOPs ARE A MUST! Standard Operating Procedures MUST be in place prior to utilizing digital imaging in the field for evidentiary purposes. The SOP should include… • When and how digital imaging is appropriate to use • Chain of Custody • Image Security • Image Enhancement Procedures • Proper Dissemination of Digital Images

  33. Court Precedence • A landmark case regarding any new technology was….

  34. Frye v. United States (1923) The resulting decision from this case is as follows…

  35. Frye v. United States (1923) • Any technique after being invented or discovered within a particular field, would first be subject to rigorous analysis by the scientific community during its “experimental stage.” Only after this community “agreed” that the technique was valid would evidence of its use be admissible in court.

  36. The IAI (International Association for Identification) reaffirms our beliefs that digital photography is a viable method of photographic documentation…

  37. International Association for Identification Resolution 97-9 “… the International Association for Identification recognizes that electronic/digital imaging is a scientifically valid and proven technology for recording, enhancing, and printing images and like conventional silver-halide base photography, it is accepted by professional commercial photographers, law enforcement photographers, and the identification community.”

  38. Going Digital

  39. So…What is a Digital Photograph? • A digital photograph is simply an image that has been created by encoding information using a binary system made up of ones and zeros, much like that of a standard computer. As a matter of fact…

  40. Your Camera IS A Computer • Each time you take a picture, millions of calculations have to be made in just a few seconds. It’s these calculations that make it possible for the camera to preview, capture, compress, filter, store, transfer, and display the image. All of these calculations are performed by a microprocessor in your camera that’s similar to the one on your desktop computer.

  41. How Does A Digital Camera Work?

  42. Instead of film, digital cameras use a solid-state device called an image sensor, otherwise known as a CCD (Charged Coupler Device). On the surface of each of these silicon chips is a grid containing millions of photo sensitive diodes called photo-elements, or PIXELS.

  43. CCD’s • The area of 35mm film is 24mm x 36mm, whereas the area of a CCD could be as much as 40% smaller. This will result in correspondingly shorter focal lengths from your lenses. Typical sensor size of Typical sensor size of 3, 4, and 5 megapixel camera 6 megapixel cameras

  44. Images captured on a digital camera with a 1.6 magnification ratio on the CCD look like this… Film Digital 100mm Lens 35mm Lens

  45. What exactly is a pixel? • Short for “picture –element" a pixel is the smallest picture element of a digital image. Pixels are similar to grain in a photograph.

  46. The Exposure • When the shutter is released and light hits the sensor, each pixel on the sensor records the intensity of the light that falls on it by accumulating an electrical charge. The more light that hits the pixel, the greater the electrical charge. When the shutter is closed and the exposure is complete, each pixel is measured and given a digital number.

  47. Pixels do NOT record color, only brightness values. The pixels record only in gray scale, a series of 256 increasingly darker tones, ranging form pure white to pure black. The sensor reacts to the AMOUNT of light hitting it, not color of light. No color information is passed on.

  48. Creating Color From Black & White • Since daylight is made up of red, green, and blue light, placing red, green, and blue filters over individual pixels on the image sensor can create color images.

  49. Creating Color From Black & White • With filters in place, each pixel records only the brightness of the light that matches its filter when passing through it, while other colors are blocked. For example, a pixel with a red filter knows only the brightness of the red light that strikes it.

  50. Creating Color From Black & White • This step is very computer intensive since the comparisons with as many as eight neighboring pixels is required to perform this process properly.