After arrival at the ED, the patient should remain clothed until it is time to conduct the examination, if possible. Once a patient consents to evidence collection, the steps delineated in the evidence-collection kit should be followed. A thorough history of the sexual assault should be obtained (see the bulleted list under Victim Interview on page 92). The patient’s general appearance and demeanor should be documented objectively. Along with the vital signs, the patient’s height, weight, and color of eyes and hair should be noted. Once evidence collection begins, the examiner should wear gloves to prevent DNA contamination. The patient’s clothing should be observed for rips, tears, odors, stains, and other foreign materials, including fibers, hair, twigs, grass, soil, splinters, glass, blood, and seminal fluid. Before the patient’s clothing is collected, it should be scanned for fluorescent exudates (using a Wood’s lamp), and positive areas should be noted in the examination report. All clothing worn during and immediately after the assault should be collected and labeled and its collection should be documented (Table 6-1). If the victim is not wearing the clothing worn at the time of the assault, then only the items that are in direct contact with the victim’s genital area need to be collected. The police officer in charge should be informed to arrange for collection of the clothing worn at the time of the assault.

The proper method of collecting the clothing is to have the patient stand on two sheets of clean paper on the floor, one sheet on top of the other. The disposable paper placed routinely on examination tables can be used for this process. The purpose of the bottom sheet of paper is to protect evidence on the clothing from being contaminated by debris or dirt on the floor. The top sheet is submitted to the crime laboratory. The patient should remove her/his shoes prior to stepping on the paper for disrobing to avoid contamination of loose trace evidence with nonevidential debris from the shoe soles. The shoes should be collected and packaged separately. The victim’s clothing should not be shaken, because microscopic evidence could be lost. Holes, rips, or stains in the victim’s clothing must not be disturbed by cutting. In the case of a ligature, the knot should not be untied (see the explanation in the next section).

A thorough head-to-toe skin surface survey must be conducted. The skin should be searched grossly for evidence of bleeding, lacerations, abrasions, bruises, erythema, edema, scratches, bite marks, burns, stains, moist and dried secretions, and foreign materials. Different patterns of trauma are associated with an assailant’s efforts to stop the victim from screaming: clamping the hand over the mouth, use of adhesive materials over the mouth, gagging. The mouth and lips must be inspected for evidence of trauma or residual adhesive material. Marks of brute force or strangulation should be sought. The presence of ligature marks, bruises, abrasions, or scratches on the neck should be noted. Swabbing these areas for DNA using a wet and then a dry swab has led to an increase in DNA findings. Gagging and strangulation both lead to asphyxia and may result in physical evidence, such as scattered petechial hemorrhages over the face and the eyelids. Subconjunctival hemorrhages and retinal hemorrhages may also result from attempted strangulation (29,39).

The perpetrator may have used ligatures or tape (e.g., duct tape) to restrain the victim. If ligatures are still in place, the entire ligature and its placement (including the knot) should be photographed before its removal. Then the ligature can be cut away
from the knot, taking care not to destroy the knot, which may be a signature of the assailant. The physical signs of restraint, usually on the ankles and/or wrists, vary and depend on the tightness, resistance, and the length of time the victim was restrained. The patterned abrasion or bruise at the site of the restraint may range from tenderness to slight erythema of the skin to a deeper skin lesion with distal edema (29).

With the lights darkened in the room, the entire body should be scanned with a long-wave ultraviolet light (Wood’s lamp/Bluemaxx light), searching for fluorescent exudates. The ultraviolet light reveals evidence of dried or moist secretions, stains, fluorescent fibers, and subtle injuries (such as rope marks and contusions) not readily visible in white light. If findings are noted, their location, size, and appearance should be documented in the text and on the schematic figures of the body. Photographs of the skin trauma should be taken. If photographs are to be taken of injuries that are visible only in ultraviolet light, the examiner may want to rely on local crime laboratory experts. Photographic documentation of these subtle injuries requires a longer exposure time and the use of a stationary tripod in a darkened room. Photographs of bruises may be helpful in defining the object that inflicted the injury (patterned injury).

With the proper technique, photographs of bite marks assist in identifying the perpetrator. If the bite mark has broken or perforated the skin, the creation of a cast by a forensic odontologist, if available, may be indicated. This evidence can be compared with court-ordered impressions and wax bites from the suspect. A typical human bite mark is a round or oval ring-shaped lesion with two opposing, often symmetric, U shapes with open spaces at the bottom. The intensity of force behind the bite affects the pattern depth and characteristics (i.e., the pattern may have abrasions, contusions, or lacerations in the area of the teeth) (40) (Figs. 6-5 and 6-6, see color plate). The classic bite mark shape is not always present, so if a bite mark is suspected, then forensic evaluation of the lesion is indicated. In documenting the bite mark, the site, size, shape, color, and type of injury are noted (e.g., contusion with ecchymosis, abrasion, laceration, incision, avulsion, petechial lesion). Findings such as smooth skin or indentation of the skin by teeth should be noted. If the patient gives a history of being bitten in a certain area but tenderness is the only physical sign noted, the clinician must remember that bruises and bite marks may not be apparent immediately following an assault but can develop later. A recommendation should be made to the police to arrange for a follow-up examination and additional photographs by the crime laboratory after the bruising has developed more fully. Serial photographs have been recommended by law enforcement and should be taken for 6 days at 24-hour intervals, because bruises and bite marks become more evident with time.

The perpetrator’s saliva and residual epithelial cells on bite mark wounds should be collected using the two-swab technique for the collection of dried secretions. The outside border of the bite mark should be swabbed toward the center of the bite mark, first with the wet swab, then the dry one. Some local protocols specify the use of two moist swabs together. The greatest amount of saliva is usually deposited in the area of the bite mark caused by the lower teeth. Both swabs must be allowed to dry thoroughly, the wet swab for at least 1 hour. Then both swabs are submitted for the forensic analysis of DNA.

Along with textual, diagrammatic, and photographic documentation, evidence on the patient’s body (e.g., foreign materials, dried and moist secretions, and stains) should be collected properly. Foreign materials include fibers; hair; grass; dirt; and thicker stains of semen, saliva, or blood. A separate “miscellaneous” envelope should be used for each location on the body from which foreign material is collected. The envelope should be labeled with the term “debris” and the materials and the site of collection should be noted. The separate foreign material envelopes are sealed and placed in the main miscellaneous evidence-collection envelope. Location of the foreign material should be recorded in the text and marked on the diagram. For the collection of foreign materials, a tweezer, a glass slide, or the dull side of a scalpel blade can be used to gently loosen or scrape the foreign substance onto the opened and flat miscellaneous paper collection
envelope. Sometimes the use of a cotton-tipped swab moistened with sterile water can be helpful. The paper envelope should be refolded in a manner to retain the scraping and debris. If heavily crusted semen or blood is found on the pubic hair, the matted hairs bearing the specimen should be cut out and placed in a collection envelope, which is then labeled and sealed.

If the victim gives a history of scratching the assailant or if foreign material is observed under the nails, fingernail scrapings should be collected, as they may contain blood and/or tissue of the perpetrator or other evidence from the crime scene. The right- and left-hand collections are performed as separate procedures. Most sexual assault examination kits provide the two fingernail scrapers and the collection envelopes required for the procedure. Each of the victim’s hands should be held over an unfolded, flat collection paper. Then scrapings are taken from under all five fingernails and the debris is allowed to fall onto the paper. The used scraper is placed in the center of the paper, which is then refolded to retain the debris and the scraper and placed in a labeled envelope. The two envelopes are identified as containing “right-hand fingernail scrapings” or “left-hand fingernail scrapings.” The nails may also be swabbed using a cotton swab moistened with sterile water.

Evidence specimens of thin secretions and stains from blood, semen, and saliva need to be collected properly to improve the forensic yield when they are subjected to genetic typing tests, most importantly DNA testing. The method of collecting evidence from moist secretions or stains differs from that involving dried secretions or stains. Both methods use swabs supplied in the sexual assault evidence kit. If the number of swabs is not sufficient, a sterile cotton-tipped swab can be used. Each suspicious moist or dried secretion, stain, or fluorescent area needs to be approached as a separate procedure with separate swabs and labeled in detail. When bloodstains are present, the stain pattern should be photographed before the evidence is collected. The area is swabbed, and injuries that might be associated with the blood should be noted.

The two-swab technique is used for dried secretions or stain areas noted on the gross visualization examination and with the light-scanning procedure (41). The first swab is moistened with sterile distilled water and then used to swab the evidence area. When wetting the swab with sterile water, one drop should be used, if possible, rather than saturating the swab. The amount of moisture applied to the swab can be controlled by using a 10-mL syringe into which distilled water has been drawn. This technique is generally adequate for obtaining the specimen and facilitates drying in a timely manner. Both swabs must be dried thoroughly—the wet swab for at least 1 hour with either a stream of cool air or on a drying rack. The second swab is left to dry and is used to swab the same site as the wet swab. Once the wet swab has dried, both swabs from one evidence site are packaged together in the original wrapper. The wrapper is labeled with the evidence-collection site and placed in the main miscellaneous evidence-collection envelope. If evidence is collected from a moist area of secretion or stain, a dry swab is used to avoid dilution of the evidence. The swab is allowed to air-dry for at least 1 hour and is then placed in a labeled envelope or tube, which is then sealed. If the swabbed area (moist or dried) was found with the use of a Wood’s lamp, “W.L.” should be marked on the envelope. The findings are recorded, and the locations of the secretions or stains are noted in the text and on the diagram of the body.
Sometimes a hand or arm print will show up on the Wood’s lamp examination. It is important to swab and document these areas because they may contain epithelial cells from the assailant.

Dried semen stains have a characteristic shiny, mucoid appearance and tend to flake off the skin. Under an ultraviolet light, semen usually exhibits a blue-white or orange fluorescence and appears as smears, streaks, or splash marks. Because freshly dried semen may not fluoresce, each suspicious area should be swabbed, whether it fluoresces or not, with a separate swab. Not all fluorescent areas observed under ultraviolet light are indicative of seminal fluid; therefore, forensic confirmation of the findings is necessary.

Reference samples, including blood and head and pubic hair, are collected to determine whether the specimens are foreign to the patient. They are also used for comparison with specimens from potential suspects. Plucking of hairs from the patient’s head permits the evaluation of hair length as well as the variation of natural pigment or hair dyes from the root to the tip of the strand. Patients should be given the option of pulling out their own hair reference samples, as this gives them the feeling of having more control over the situation. A minimum of five full-length hairs should be pulled from each of the following scalp locations (total of 25 hairs): center, front, back, left side, and right side. The hairs should represent variations in length and color. They are placed in an envelope, which is labeled and sealed. (If a patient has attached synthetic hair, samples of both the synthetic hair and the real hair should be collected, and a notation made on the outside of the collection envelope that both have been included.)

Reference samples of pubic hair can be collected simultaneously with the pubic hair evidence collection. A sheet of paper should be placed beneath the patient’s buttocks. The pubic hair is combed forward from the mons pubis toward the vaginal area first, to remove any loose hairs or foreign materials that may have transferred from the assailant to the patient during the assault. The loose hairs, foreign materials, pubic hair, and comb are placed in the sheet of paper, which is then folded with the contents inside. The folded paper and its contents are placed in a large labeled envelope, which is then sealed. Then, samples of the patient’s pubic hairs are needed for comparison with the suspect’s hairs. The patient or the examiner needs to pluck at least 10 to 15 hairs of various lengths and color from the pubic area (42). The hairs can be compared microscopically, and if hairs foreign to the victim are identified, they can be tested utilizing polymerase chain reaction (PCR) DNA. (Some crime labs request that the hairs be plucked later, when requested by laboratory personnel.)