The purpose of major case prints is to record all friction ridge detail

Transcription

1 Chapter 12 Major Case Prints The purpose of major case prints is to record all friction ridge detail so that complete and accurate finger and palm print comparisons can be completed. This includes the fingers, fingertips, finger joints and edges of the fingers as well as the entire palm. Major case prints should be taken of all felony suspects and victims of homicide. Major case prints were traditionally taken by inking all friction ridge skin on the underneath portion of the hands and transferring the detail to a white card (the ink method). In more recent years, the powder and tape method has been used and is the preferred method at the Laboratory. Both methods are addressed in this chapter. I. Powder & Tape Method Equipment Needed A. Black powder (traditional or magnetic). B. 1.5 and 4 clear tape. C. Fingerprint brush or magnetic applicator. D. 8 x 10 or larger clear acetate sheets. Fig Equipment needed for the powder and tape method. NOTE: White opaque tape may be used instead of clear tape for additional contrast. 113

2 Major Case Prints 12 Recording the Fingers A. Black fingerprint powder is lightly applied to the fingers and palms (see Figure 12-2). B. Starting with the right thumb, powder is applied until all of the elevated ridges of the finger have been darkened. C. A 2 to 3 inch length of clear tape is attached to the fingertip and spread down the finger towards the palm (see Figure 12-3). D. The outer edges of the tape are then molded around the edges of the thumb to cover the remaining ridge detail. E. The tape is then lifted and attached to the clear acetate (see Figure 12-4). F. Be sure to label each fingerprint on the acetate and repeat the above procedure until all fingers have been recorded. Fig Lightly dust finger with black powder. Fig The dusted finger with tape attached. Be sure to cover the very tip and sides of the finger. Run the tape down towards the palm. 114

3 Fig Attach the tape to clear acetate. Be sure to label each fingerprint. Note: Friction ridge detail recorded using tape is in a reversed position when attached to acetate. Recording the Palms A. Lightly brush the palms in the same manner as the fingers (see Figure 12-5). B. Using 4 tape, smooth the tape onto the palm from the bottom of the fingers to the wrist (see Figure 12-6). C. Any areas not covered by the 4 tape can be covered with the narrow tape. The narrow tape should overlap the 4 tape enough to allow the removal of both pieces of tape as one lift. D. Be sure to wrap the ends of the tape over the edges of the palm so that all friction ridge detail is recorded. E. Care should be taken depositing the lift onto the clear acetate to ensure creases are avoided (see Figure 12-7). Major Case Prints 12 Fig Lightly dust the palm with black powder. Note: An alternative to dusting is to rub a light coat of black powder onto the fingers and palm. 115

4 Major Case Prints 12 Fig Smooth 4 tape over palm from the bottom of the fingers to the wrist. Fig Attach tape to clear acetate taking care to avoid creases. This process is repeated until clear and legible prints are obtained for all ridge detail of the fingers and palms. Benefits of the Powder and Tape Method A. B. C. D. E. Less time to complete than inked major case prints. Little or no cleanup. Powder covers ridge detail more evenly. No rolling of fingers or palms to cause smearing. Gives greater detail in one recording. II. Ink Method Equipment Needed A. An ordinary inking standard for taking a tenprint card. B. A roller for spreading ink on the fingers and hands. C. Black printers ink. D. A cylinder, 3 or more in diameter, for rolling palms. E. At least (4) plain white Fig cards (8 x 8 ). Equipment needed for the ink method. 116 *Physical Evidence Master File.indd 116 6/9/09 2:56 PM

5 Recording the Fingers A. The first step to taking major case prints is to roll a standard tenprint card (see Figure 12-9). Each finger should be rolled from nail edge to nail edge to obtain the entire width of the pattern area. Care should be taken to also include as much of the tip and the first crease as possible. B. After the tenprint card has been properly recorded, the entire finger is then inked for recording the inner edge, middle, outer edge and tip of each finger. This step will require the use of at least two 8 x 8 cards (see Figures and 12-11). C. Starting with the thumb of either hand, the outer edge or side of the inked thumb is placed on the card and rolled 45 inward towards the middle. D. The middle area of the thumb is then placed on the card next to the rolled outer edge. E. The inner edge of the thumb is recorded in the same manner as the outer edge. F. The thumb is then completed by recording the tip area, placing it on another sheet (as in Figure 12-11) or above the previously recorded areas. Major Case Prints 12 This process is repeated until all friction detail is recorded and the prints are clear and legible. Fig Tenprint card with properly recorded inked prints. Fig Rolled tips of fingers and thumbs. Fig Outer, middle and inner edges of fingers and thumbs. 117

6 Major Case Prints 12 Recording the Palms A. Attach an 8 x 8 card to the cylinder using rubber bands on each end to avoid movement during rolling. B. Apply a thin layer of ink to the palm and fingers (see Figure 12-12). C. Roll the hand onto the 8 x 8 card attached to the cylinder. The wrist area of the palm is placed onto the bottom edge of the card and rolled gently backwards towards the body (see Figure 12-13). A hand placed on the back of the palm, using a slight downward pressure will help ensure the entire palm is recorded properly. D. The outer edge of the palm is then recorded on the card (see Figure 12-14). E. The palm is completed by rolling the inner edge of the palm on the card (see Figure 12-15). This process is repeated until all friction detail is recorded and the prints are clear and legible (see Figure 12-16). Fig Ink the palm and fingers with a thin uniform coat. 118

7 Major Case Prints 12 Fig Place the palm of the hand on the cylinder and roll the hand to the fingertips maintaining pressure on the hand. Fig The outer edge of the palm is recorded. Fig The inner edge of the palm is recorded. Fig Ridge detail of the palm is recorded from the base of the palm to the fingertips and both the inner and outer edges of the palm. A sheet of paper can be used to protect the rest of the document when recording the inner and outer edges of the palm. 119 *Physical Evidence Master File.indd 119 6/9/09 2:56 PM

8 Major Case Prints 12 Drawbacks of the Ink Method A. Hard to apply an even coating of ink to all areas of hands and fingers uneven results. B. Rolling of hand often introduces slippage duplicate cards must be taken until documented properly. C. Requires equipment not always handy to the scene technician. D. Uncooperative persons can affect outcome by movement. E. Can take upwards of 45 minutes to an hour to complete. Examples Illustrating the Two Methods Inked Powder & Tape 120