Consent

In sexual assault evaluations, two separate consent processes exist: consent for medical diagnosis and treatment and consent for forensic examination and evidence collection. It is recommended that health care professionals obtain both written and verbal consent before conducting a medical examination and forensic evidence collection in sexual assault victims. Patients must be provided with all relevant information regarding their examinations, and it must be provided in a way that is clearly understandable. Patients can decline all or any part of an examination. Examiners should inform the patient of the risks of refusing any part of the examination, including how their decisions might affect their medical treatment and the investigative process. Consent is required for forensic examination and evidence collection including the following: photographs, toxicology screening, and examination and evidence collection.

Examiners must also refrain from any coercive practices when obtaining consent. If the child cannot tolerate the examination, the importance of the examination and evidence collection should be reassessed. If deemed necessary for either medical or forensic reasons, sedation or anesthesia should be considered for the child. Policies regarding consent for medical evaluation and treatment are generally established by the treating facility. Aspects of the examination that require this type of consent include: general medical care, pregnancy testing, testing and prophylaxis for sexually transmitted infections (STI) and HIV, and release of medical information.

Typically, consent should be obtained from both the parent and the child. Different jurisdictions have different consent requirements. For example, in some jurisdictions, minors can give consent to receive care for STIs, but not a forensic examination. Other jurisdictions have laws that allow children to consent to both the examination and evidence collection. Some states permit physicians to evaluate minors for abuse without parental consent.

Collection and Handling of Evidence

Standardized protocols, typically established in conjunction with the local police department and forensic laboratory, eliminate the need for hospital personnel to testify at each trial about how the evidence was collected and how chain of custody was maintained. Protocols also can eliminate errors of omission in the process.

Before beginning the examination, all equipment, containers, and other necessary materials should be in the room, and if possible, covered before the child’s entry. The following should be available :

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  A copy of the jurisdiction’s most current evidence collection protocol;

  
  
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  A private examination room with an obstetric/gynecological examination bed;

  
  
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  “Comfort supplies” such as a change of clothes for the victim or materials to distract a child during the examination;

  
  
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  Sexual assault evidence collection kit (see Figure 13-1 ) and related supplies;

  
  

  
  

  
  

  

  
  

  
  

  An example of a forensic medical evidence kit.

  
  
  
  
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  A method or device to dry evidence;

  
  
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  A camera, ruler, and related supplies for forensic photography;

  
  
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  Testing and treatment supplies;

  
  
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  An alternate light source, if available;

  
  
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  A colposcope with photographic ability or alternative method for detailed photodocumentation; and,

  
  
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  Written materials for patients on the sexual assault examination, counseling resources, STIs, and other medical and legal information.

The examiner should always wear gloves throughout the entire examination to avoid contamination of evidence. Evidence should be placed in paper bags rather than plastic to prevent mold, bacterial, and fungal overgrowth that can occur with moisture retention. Once collected, evidence in envelopes should be sealed with moistened gauze, as opposed to licking the envelopes, to prevent contamination. All swabs and other evidence collected should be completely air-dried in a clean environment, again, to prevent contamination. A drying box will facilitate the process. Protocols should be established for handling specimens that will not dry immediately, such as tampons, condoms, wet clothing, or diapers. Collected specimens should be labeled with the child’s name, date, and time of collection, site from which the specimen was taken, and name of the person collecting the evidence. Once evidence is appropriately processed, packaged, and labeled, it should be stored in designated locked cabinets, freezers, and refrigerators. Kits with wet evidence or drawn blood need to be refrigerated. Urine should be frozen or refrigerated. Previously, it was felt that any biological evidence possibly containing DNA should be stored at very low temperatures. However, preliminary information from the National Institute of Standards and Technology suggests that DNA samples might not need refrigeration.

Clothing

After consent is obtained and the materials needed for collection are organized, the victim should disrobe over two clean sheets of paper. The upper sheet allows for collection of any evidence that falls off the child as she/he undresses. The lower sheet prevents contamination from the examination room floor and should be discarded. If the child cannot undress on her own, or the condition of the victim is such that it is necessary to cut off items of clothing, do not cut through existing stains or tears. Tears or cuts in clothing might be evidence of a physical struggle. Each piece of clothing and the collection paper on which the victim disrobed should be placed in separate paper bags. These bags are then labeled, sealed and signed. If the child is not wearing the same clothing that she wore during the assault/abuse, the examiner should inquire about the location of this clothing and then notify investigators so the clothing can be retrieved before the degradation of biological evidence. The examiner should collect the clothing the child has on even if she has changed, as secretions on the child might have been deposited on the clothing in the interim. Any evidence that cannot be dried thoroughly at the collection site (wet clothing or tampons) should be packaged in leak-proof containers and separated from other evidence while being transported.

Swabs

Some protocols call for collection of swabs from the mouth, body, vagina, perineum, and anus in all cases, regardless of the history provided by the victim. The rationale for this approach is that the victim’s recollection of the event might not be complete or supportive of other evidence collected. The totality of evidence must be carefully interpreted. For example, studies have documented the presence of sperm in the anal canal despite no history of anal penetration. Large numbers of sperm were also reported in vaginal contents in these cases. The authors interpreted this as contamination of the anus with vaginal contents. Conversely, many victims, particularly children, find the examination uncomfortable and unsettling, and minimizing the trauma associated with evidence collection is appropriate. Additionally, internal vaginal swabs might not be necessary in prepubertal children who do not have apparent vaginal/hymenal injuries. Forensic evidence on these children is more likely to be in the vestibule or external surfaces, such as the perineum. In support of selective sampling of only high-yield sites, a recent national protocol recommends, “Specimens should be collected only from orifices and areas surrounding the orifices that the patients report to be involved in the assault. ”

When swabbing for forensic evidence, at least two swabs should be used at each site. One is reserved for the prosecution, the other for independent analysis. Each swab should be lightly moistened with nonbacteriostatic saline. Cotton-tipped or Dacron swabs should be used. The examiner should take special caution to prevent contamination of swabs with materials from other areas (such as vaginal secretions on a rectal swab), as the specific location of collected evidence is critical to the investigation.

Obtaining mouth swabs first allows the victim to rinse his or her mouth after specimen collection. Mouth swabs should include specimens from the buccal mucosa, the gum line, between the teeth, and underneath the tongue. Some protocols stipulate the use of dental floss for obtaining specimens from between the teeth. The victim’s entire body and hair should be searched for evidence of secretions, blood, other stains, or foreign material such as grass, dirt, or fibers. An alternate light source will assist in identification of suspicious areas. Additionally, any areas that might be high yield based on the victim’s history should be swabbed. General high-yield areas, such as the neck, external genitalia, and breasts, should be swabbed if the history is absent or incomplete. If vaginal swabs are to be collected in a prepubertal child, the swab should be placed through the hymenal opening and rotated several times. Care should be taken to avoid touching the hymen, which is uncomfortable for the prepubertal patient. A vaginal wash can sometimes yield assailant secretions. To perform this procedure, 2 to 3 ml of nonbacteriostatic saline is instilled into the vagina with a dropper. The saline in the vagina is then aspirated using a dropper and stored in a sterile glass tube. A wet mount can be done by placing a drop of saline on a glass slide, mixing the saline with one of the specimen swabs, and then placing a cover slip over the sample. After viewing under the microscope, the wet mount slide should be packaged, labeled, and sent to the forensics lab with all other collected evidence.

Swabs from both the vaginal vault and cervical os should be taken when a vaginal speculum examination is possible (only in postpubertal patients). Any contraceptive or sanitary devices identified should be collected and retained as evidence. To collect a rectal specimen, place the swab 1 inch into the rectum, rotate, and remove it. Using two slightly moistened swabs, swab the external genitalia area.

Blood, buccal swabs, or saliva “control” samples can be collected to distinguish the patient’s DNA from that of the suspect. Use of a buccal swab or saliva is suggested as it is the least invasive method of DNA collection, although a buccal or saliva sample might be contaminated with the perpetrator’s DNA as well. When oral-genital contact is suspected, a blood sample is preferred to confirm the victim’s DNA typing. If blood is not being drawn for medical purposes, a dry blood sample should be considered. For this procedure, the victim’s fingertip is cleaned with Betadine, and then pricked with a sterile lancet. Drops of blood are collected on a blood collection card, dried, and packaged.

For male patients, the presence of feces, vaginal secretions, or saliva on the penis can be used as evidence of assault or abuse. At least two swabs should be taken from the penile shaft and glans.

The examiner might identify secretions such as semen, saliva, or blood on other parts of the victim’s body. If dry, this material should be collected by moistening a swab with sterile water and swabbing the identified area. Alternatively, dry secretions can be flaked off with a sterile instrument and collected. Moist secretions can be collected with a dry swab. Any head, facial, or pubic hair matted with dried secretions should be cut and placed into an evidence envelope.

Semen/sperm: Multiple factors must be considered when evaluating the presence of sperm or semen after an assault. Activities of the victim, such as running, walking, defecating, urinating, spitting, or brushing teeth, are thought to decrease the longevity of sperm. No sperm will be recovered if the assailant is azoospermic, impotent, or vasectomized. At the bedside, semen can be identified by microscopic examination of bodily fluids and the observation of motile sperm or nonmotile sperm. Motile sperm can be detected using a saline wet mount. Nonmotile sperm are detected by gram stain, Papanicolaou smear, or nuclear fast red-picroindigocarmine (“Christmas tree”) stain.

Previous sources have documented time frames for the persistence of sperm and other markers in the vagina, oral cavity, and rectum. However, motile and nonmotile sperm have been recovered from these sites well beyond the accepted timeframes. Typically, motile sperm rarely persist for longer than a few hours after intercourse. Yet, motile sperm have been detected in the endocervix up to 7 days after intercourse, and have been reported in vaginal samples up to 24 hours after intercourse. Even in a controlled environment with volunteer couples, only 50% of women tested positive for motile sperm 3 hours after intercourse. Nonmotile sperm can be found beyond 72 hours in vaginal samples from nearly 50% of postcoital women, and have been detected up to 17 days after intercourse. Vaginal douching was found to reduce the percentage of spermatozoa found in vaginal smears.

Sperm persists for a shorter time in the rectum. It is uncommon to recover sperm from anal swabs beyond 6 hours. Sperm is rarely found in the oral cavity beyond a few hours, but has been documented up to 13 hours after an alleged offense. Others report persistence of sperm up to 28 to 31 hours in the oral cavity . Additionally, both saliva (obtained by having the patient expectorate saliva) and swab samples may be necessary to detect all sperm in the oral cavity.

Bite Marks

Some victims of sexual assault have evidence of bite marks on their skin. Bite marks frequently contain useful forensic evidence (see Chapter 60 for a discussion on preserving and interpreting bite mark evidence).

Hair

Any hairs seen on the victim should be collected for forensic analysis. Hairs may be transferred via direct contact, clothing transfer, friction, or forcible removal during an assault. Hair, particularly head and pubic hair, can be compared to known samples from the victim and alleged perpetrator. The victim’s hair should be combed over a piece of paper to collect any loose hairs or fibers. The comb and materials gathered from the combing are then folded into the paper, placed into an envelope, and labeled. This procedure should be repeated with the pubic hair. Many patients, if capable, prefer to do this procedure themselves to minimize embarrassment. Though combing is more comfortable for the patient, plucked hair is more likely to contain roots and is better for DNA analysis. Many jurisdictions do not collect victim hair samples routinely during the examination. However, samples of the victim’s hair might be requested at a later time, depending on evidence found at a crime scene. The family and victim should be told to avoid having the victim’s hair processed, colored, or cut before completion of the investigation. Protocols typically require hair to be collected from multiple areas of the scalp (sides, top, front, and back) with up to 100 hairs being collected.

Nails

If the patient states that he/she scratched the alleged perpetrator’s body or clothing, or if material is noted under the patient’s fingernails, the nails should be scraped individually with a solid implement or a cotton swab lightly moistened with sterile water. The nails from each hand should be scraped over a separate piece of paper, and the paper should be placed in an individual collection envelope along with the device used for scraping.

Toluidine Dye

Some previous rape kit protocols have suggested using toluidine dye on the perineum and posterior fourchette for detection of minor tissue injuries not readily visible with white light and/or magnification. ^, However, minor tissue injury to these regions is a nonspecific finding for trauma and can be caused by other irritative and infectious conditions. Toluidine dye is not a diagnostic tool, but rather accentuates minor epithelial damage that can then be photographed.

Alternative Light Sources

A Wood’s lamp produces ultraviolet radiation emitting wavelengths of approximately 320 to 400 nm. Various substances fluoresce when viewed under a Wood’s lamp. Semen placed on cotton fabric was not found to fluoresce using a Wood’s lamp, but was found to fluoresce at a wavelength outside of that emitted by a Wood’s lamp. A different light source, the Bluemaxx 500 (Sirchie Finger Print Laboratories, Inc., Youngsville, N.C.) is a more appropriate tool for identifying semen on fabric by fluorescence. The Bluemaxx 500 used in conjunction with an added orange barrier filter has been reported to be 100% sensitive in detecting semen as a fluorescing agent on cotton fabric and this fluorescence persists for at least 16 months. It should be noted, however, that other substances fluoresce under the Bluemaxx 500 in addition to semen (hand cream, castile soap, and bacitracin).

Detecting semen on skin by fluorescence is more difficult. Wawryk et al found that the light source needed to be very close to the skin (less than 3 cm) to cause visible fluorescence of the semen. In fact, dried semen was noted to be more easily visible with the naked eye than with a number of alternative light sources and filters. A Poliray light source (Rofin Forensic, Melbourne, Australia) with a filter and goggles documented semen fluorescing on various cloths and skin, but still may not be as effective as the naked eye when looking for semen on skin.

In summary, a Wood’s lamp is not likely to be useful in detecting semen on skin or fabrics. Instead, other light sources (Bluemaxx 500 or Poliray), with appropriate filters, should be used with the understanding that relatively fresh, dried semen might be more easily seen with the naked eye than with an alternative light source.

Saliva

DNA evidence can be recovered from saliva deposition after biting, licking, kissing, and sucking. Saliva can be collected with the “double swab” technique as described for bite marks.

Frequency of Forensic Evidence in Children

Few studies have examined the frequency of recovery of forensic evidence from sexually abused children. Christian et al reviewed 273 children younger than 10 years who were evaluated for sexual assault. Approximately 25% of those evaluated had forensic evidence identified, all of whom were examined within 44 hours of assault. Over 90% of those with forensic evidence present were seen within 24 hours of the assault, and 64% of the evidence was found on clothing and linens. However, only 35% had clothing collected for analysis. After 24 hours, all evidence, with the exception of 1 pubic hair, was recovered from clothing or linens. No swabs taken from the child’s body were positive for blood after 13 hours or sperm or semen after 9 hours. Of the children evaluated, 23% had genital injuries. Genital injury and a history of ejaculation provided by the child were associated with an increased likelihood of identifying forensic evidence, but the forensic evidence recovered in several children was unanticipated by the child’s history. The authors concluded that swabbing a young child’s body for evidence is probably unnecessary after 24 hours, but clothing and linens should be obtained for analysis whenever possible.

A 2006 study by Palusci et al evaluated the presence of sperm or semen in children under the age of 13 evaluated within 72 hours of assault. Of 190 subjects, 9% had positive findings; 6.5% of body swabs and 12.5% of clothing analyzed had sperm or semen found. Semen or sperm was identified from body swabs only from female children older than 10 years who had not bathed since assault. All other semen or sperm was recovered from clothing or objects. No child under the age of 10 had a positive body swab, but some with negative body swabs had positive evidence on clothing. Factors that best predicted forensic evidence findings were: victim age greater than 10, older alleged perpetrator, pubertal status of victim, and victim with examination findings consistent with sexual assault. Factors that best predicted lack of forensic evidence were: alleged perpetrator less than 15 years old, victim less than 10 years old, prepubertal status, normal or nonspecific anogenital examination findings, and victim changing clothes before collection of evidence.

Young et al reviewed 80 children evaluated within 72 hours of sexual abuse. Sixteen of the 80 cases had positive findings for semen. All 16 of those subjects presented for evaluation within 24 hours of the last assault or abuse. Of those older than 12 years, 13 of 31 had semen identified. Of those younger than 12 years, 3 of 49 were positive for semen, and in those 3 children, semen was recovered only from clothing or linens.

These studies indicate that younger children rarely have positive body swabs after sexual abuse, and clothing and linens should be collected and analyzed whenever possible. Additionally, although there are associations between the likelihood of forensic evidence recovery and several factors including ages of the involved parties, timing of the abuse relative to the examination, and other specific aspects of the abuse, each case requires individual considerations and careful assessment.