«DESCRIBING TYPES OF PRINTS 20-1. Latent prints can be seen or unseen and often require development. The word “latent” means “hidden,” but ...»
Fingerprint evidence remains the most positive means of personal
identification in forensics, to date. Though often compared with other
modern innovations such as DNA, fingerprint evidence results in positive
identifications whereas other evidence does not. Fingerprint evidence can
also distinguish between identical twins. Identifications can be effected
from fingerprints made in a victim's blood, paint, or other contaminants,
which no other form of evidence can accomplish. There should not be competition between fingerprint evidence and other innovations because all should work hand in hand to solve identification questions.
DESCRIBING TYPES OF PRINTS20-1. Latent prints can be seen or unseen and often require development. The word “latent” means “hidden,” but normally the term latent prints refers to those prints left at crime scenes and/or on items of evidence. Another category of latent prints is patent prints. Patent prints are impressions that are visible in some form of contaminant. Plastic prints are those impressions left in materials, such as wax, window putty, or other pliable materials.
20-2. Record prints are the controlled recordings of the friction ridge skin contained on the palms of the hands and each finger, using various methods such as fingerprint cards, printer’s ink, or electronic recording by way of “live scan.” Though there are many variations on how to obtain record prints, the principles are the same. Traditionally, the term major case prints refers to finger and palm prints. Record prints can also be taken from feet, which also bear friction ridge skin. Record prints must be submitted for all victims, witnesses, suspects, medical and law enforcement personnel, and anyone known or suspected of handling evidence or entering a crime scene. Once legible and complete elimination prints for investigators are on file at USACIL, there is no requirement to resubmit record prints for each investigation conducted. In some cases, it may be necessary to record ear and lip prints for comparison. The laboratory should be contacted for guidance in these cases.
Fingerprints 20-1 FM 3-19.13
SEARCHING FOR, IDENTIFYING, AND PROCESSING LATENT PRINTS20-3. Prints deposited on items of evidence are generally divided into the
following two basic categories:
Porous evidence. This type of evidence can absorb fingerprint
PRESERVING LATENT PRINTS20-4. Latent prints on nonporous evidence are often deposited on the surface of an item and are extremely vulnerable. Wearing gloves does not protect the latent prints from being destroyed if they are touched, rubbed, or smeared;
they only prevent additional prints from being deposited. When it cannot be determined from appearance whether a drop of water would be absorbed into a surface, the evidence should be handled and processed as nonporous (such as a leather wallet, cigarette cartons, and shiny cardboard boxes).
Photography, superglue-fuming, and fingerprint-powdering are techniques used to preserve latent prints.
PHOTOGRAPHY20-5. The very first step in latent print preservation is photography. Visible latent prints should always be photographed to prevent the loss of evidence.
Latent prints deposited in grease, blood, paint, and other visible substances will often not require additional processing before photography. Always use a scale in evidence photography and steady the camera using a tripod. It is best to use a macro lens, filling the entire frame. Do not use digital photographic field-issued equipment; digital photography has not advanced technologically for the recording of latent print evidence. Traditional photography is still required for latent print evidence to be suitable for identification. If there is no other choice but to use digital photography, use maximum resolution (largest photo file size) settings combined with good lighting and a tripod.
20-6. Attempt to keep the back of the camera parallel to the surface bearing the latent print. If it is necessary to photograph the evidence from an angle to catch the light in a manner that increases the contrast of the latent print, additional photographs should also be made of the same area with the camera back parallel to the surface bearing the latent print.
LIFTING LATENT PRINTS20-14. The most common means used to lift latent prints are commercially produced lifting devices, such as hinge lifters, lifting tapes, rubber and gel lifters, and various types of liquid lifting mediums. Hinge lifters and transparent lifting tape have the advantage of presenting the lifted latent print in its correct perspective. Latent prints on rubber lifters are in a reversed perspective and must be reversed again using photographic techniques to properly visualize and compare the latent print. However, rubber lifters generally work better than hinge lifters. Transparent lifting tape works better for taking prints from curved or uneven surfaces.
Transparent tapes used in office work, such as cellophane tape, are not suitable for lifting fingerprints except in dire circumstances. A lift background that contrasts the color of the powder should always be used. A gel lifter is not as tacky as hinge, tape, and rubber lifters. It can be used on surfaces that are
moisture has washed everything else away. SPR is simply applied and then rinsed away with water. It also works on metal and masonry type surfaces. It can be photographed and lifted as with powdered prints, after drying. SPR comes in contrasting colors and UV formulas.
TAKING RECORD PRINTS20-22. Record prints are taken to show the entire friction ridge skin surface of the fingers, thumbs, and palms. Record fingerprints for submission to the laboratory should consist of at least two completed FBI fingerprint cards and a set of fully rolled fingers and fully rolled palm prints to include the web and side areas of the palms. (See Appendix G.) To prepare for recording the prints, the fingerprint card should be secured in the holding device. A small dab of ink should be placed on the inking plate and rolled until a thin, even film covers the surface. The consistency of the ink should appear almost opaque.
20-23. The motions for inking the finger and recording the finger are the same. The fingers are rolled from nail edge to nail edge and from approximately 1/8 inch below the crease of the first joint to as far up as possible. This area will allow for the recording of all ridge characteristics required for correct classification of each finger. The finger is rolled through the ink and then rolled in the corresponding block of the fingerprint card.
When the investigator takes record fingerprints, he should grasp the top of the subject's hand to ensure that the finger to be printed is extended. The investigator uses his other hand to hold the finger at the base where it meets the palm. He tells the subject to look away, relax, and allow him to do all the rolling. Each finger should be rolled in one continuous and smooth motion.
PROBLEM RECORD PRINTS20-27. Excessive perspiration and dirty hands and equipment may cause problems when recording prints. The investigator should always start with clean equipment and clean fingers. When the person whose fingers are being recorded are wet from perspiration, each finger should be wiped with alcohol, quickly inked, and rolled onto the fingerprint card. This process should be followed with each finger. Some people have dry and/or rough hands. Rubbing them with lanolin, lotions, or creams can often make them soft enough for clear, unsmudged prints. If the ridges are very worn or fine, alternate methods must be used to obtain prints, much like the methods for recording “postmortem records” (see paragraph 20-30). When nothing seems to work, USACIL should be consulted for suggestions and guidance.
20-28. If the hands and fingers are deformed, normal printing steps cannot be followed. The ink should be applied directly to the fingers with a spatula or small roller, and then a square piece of paper should be rotated around the finger. When an acceptable print has been made, the square is taped to the proper box of the fingerprint card.
20-29. If there is an extra finger (usually a little finger or a thumb), the innermost five are printed as usual on the card. The extra digit is then printed on the reverse of the card. Webbed fingers should be printed as best as possible in the rolled and plain impressions blocks of the fingerprint card. If a finger or a fingertip has been amputated, it should be noted in the proper box (such as AMP, 1st joint, FEB 1993 or TIP AMP).
OBTAINING RECORD PRINTS OF DECEASED INDIVIDUALS20-30. Full record finger and palm prints are always obtained from deceased individuals. The record prints are used to identify the deceased and/or eliminate them as the source of the latent print evidence. The process of taking postmortem record finger and palm prints has always been cumbersome, but it is too important to take lightly. The investigator only has one opportunity to obtain postmortem prints before the body is interned. This process must be completed with accuracy and diligence. The key is to prepare for the process.
20-31. The means used to record the prints depend on the condition of the fingers and the investigator's ingenuity. For the recently dead, the process is the same as for live subjects. The process of inking the fingers and using inking spoons and square paper tabs on the fingers might be used if rigor has started. When rigor mortis is present, the investigator may have to massage and straighten the fingers. Breaking rigor requires a certain technique, and massaging the fingers and hands takes time (about 10 minutes per hand).
Rigor can be broken using finger spoons or by bending the fingers backward and pressing down on the middle joint of the finger. If the investigator is not having any success using conventional methods, he should process the fingers and palms using equipment and other methods.
edge. Again, the investigator should gently and steadily peel the label from the finger and attach it to the back of the blank transparency. He should immediately write on the front of the transparency just below the applied label which finger it is so as not to lose track or get the labels out of order. The investigator should remember that, when viewing the ridge detail through the transparency, it is a reversal of the pattern on the actual finger. The following includes methods for obtaining fingertip prints, palm prints, and guidance for
Fingertips. The tip of the finger can be powdered and a label applied across the tip from side to side. This process should ensure that all of the ridge detail available has been captured. The recorded tip should be placed just above the corresponding finger on the blank transparency. The investigator should remember to keep all the labels for the same finger together on a transparency and label each accordingly. These same steps should be repeated for all ten fingers.
Palm prints. The investigator should use the same method for taking palm prints as he did for taking fingerprints, but this time he should use the larger mailing labels. In most cases, the investigator will have to overlap two labels in order to obtain all the ridge detail on the palms. The investigator should remember to keep those two labels together when removing them from the hand and applying them to the back of the transparency. He should gently mold the labels to cover the center of the palms, the edges of each palm, both the little finger and thumb sides, the area where the wrist connects to the forearm (the wrist bracelet area), and the interdigital area where the palm connects to the fingers.
NOTE: In some cases where fingers and/or palms are too damaged to allow for the powdering of the skin, photography or other methods may have to be applied.
Special cases. The hardest record prints to obtain are those from a body that has started to decompose. It may require techniques beyond the investigator's expertise. When the hands are badly damaged, the investigator may need to coordinate with USACIL for guidance on how to proceed.