Medical Examinations of Sexual Assault Victims
Forensic Use and Relevance
Dr Jean Edwards*
[1]The results of forensic medical examinations can be significant in sexual assault trials, as most sexual assaults do not take place in the presence of witnesses (other than the victim). Physicians and courts should take care, however, not to misinterpret or misuse the findings of forensic medical examinations.
[2]Two important questions regarding sexual assault medical examinations are:
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Why there are frequently no (or only minor) injuries resulting from the alleged assault.
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Why children who have accurately described penetration frequently have no medical injuries that are consistent with penetration.
[3]A better understanding of the physical aspects of sexual assault — anatomy, functions and healing processes — will help courts assess the weight to be given to the medical findings in any particular sexual assault matter.
Issues regarding adults
[4]The sexual assault of adults is an offence characterised by violence and coercion, rather than sex. There may be no signs of injury at all; or there may be signs of violence to the person’s body, in general, or to the person’s genital area. However, consensual sexual activity may also sometimes cause genital injury.
[5]For instance, on a number of occasions I have been asked to provide an opinion on whether it is a defence that the accused states that they are impotent and, therefore, could not possibly have been guilty of the offence with which they have been charged. Impotence has no relevance in most sexual assault matters. When taking histories from women who have been recently sexually assaulted, they will commonly indicate that the assailant appeared to have erectile dysfunction, with difficulty in maintaining an erection and failure of ejaculation. Impotence, however, does not prevent an accused from committing a variety of sexually assaultive (and inherently violent) acts, including penetration by fingers, objects or a partially erect penis.
Genital injuries
[6]The vagina is an anatomical organ with the capacity to accommodate, in most episodes of sexual activity, penetration by an erect penis without injury. This is so whether the sexual activity is consensual or non-consensual. Because the vagina has an extremely good blood supply, minor abrasions will heal, with no signs of injury, within 24–48 hours.
Other physical injuries and signs
[7]Most women who are sexually assaulted have been threatened with, or fear, violence if they do not comply. Fearing greater injury, they frequently comply. For this reason, any physical injuries may be very minor. These injuries may have little clinical significance but are forensically significant.
[8]Examples of such injuries include:
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Minor injuries on the limbs indicating restraint, such as circular marks around the wrists and ankles, when the victim was tied up.
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Bruising on the inside of the thighs rarely occurs in consensual sexual acts but may occur in non-consensual acts when the thighs are forced apart. This is a very protected part of the body that is rarely injured in normal daily activity.
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There may be scratch marks on the back, when the victim has been sexually assaulted lying on concrete or another abrasive surface.
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There may be vegetation caught in the hair or clothing, particularly where the sexual assault has taken place in bushland or parkland.
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Gravel may be pressed into parts of the body, such as the knees or buttocks.
[9]Of course, each set of facts is unique and impact upon the degree of physical evidence available.
[10]Circumstances tending to lead to substantial signs of injury in adults include:
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Sexual assault as part of a domestic violence situation.
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Sexual assault by multiple assailants.
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Vigorous repeated acts of vaginal penetration.
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The use of physical restraints and force.
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Lack of recent sexual activity, specifically women who have not been previously sexually active or women who have been sexually inactive for a prolonged period of time.
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Post-menopausal females subjected to vaginal penetration.
[11]Circumstances tending to lead to a lack of substantial signs of injury in adults, include:
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Threats causing compliance.
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The use of weapons.
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Drug-facilitated sexual assault.
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Fear causing the victim to “freeze” and comply.
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Late presentation, enabling injuries to heal prior to examination.
[12]Reasons why the Sexual Assault Investigation Kits frequently do not show evidence of semen, include:
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Delay in taking the samples, due to late reporting.
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Failure of the accused to ejaculate.
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Use of a condom by an accused.
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Ejaculation away from the body of the victim.
Issues regarding children
Imprecise language
[13]Adolescent or post-pubertal children may be involved in sexual assault that closely resembles adult sexual assault, and the above information applies to them. The perpetrators of sexual assault against pre-pubertal children, however, tend to function in a different way. They tend to use the body of the child as a masturbatory object.
[14]Children frequently use play words to describe the human genital area, and may use the same word for both the vagina and the anus (for example, “bottom”). It is extremely important that the actual words used by the child are considered, as the following errors may occur in assessing the accuracy of the child’s history:
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The child may use the word “vagina” to mean the genital area and, hence, penetration may be into the genital area but not, anatomically, into the vagina.
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The person to whom the child spoke of the assault may also use the term “vagina” to mean the genital area, not the anatomical structure of the vagina.
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A similar error may occur when a child says things like “he put his willy into my bottom” or “he put his front bit in my back bit.” For both girls and boys, this may mean that the penis was placed between the buttocks, not necessarily into the anal canal.
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When the child says “in” they may mean “on”, “against” or “partially inserted” into the genital area.
Rapid healing
[15]Because the genital area of young children has an extremely good blood supply, it heals very rapidly, usually without scarring. Unless the child is examined within 24–48 hours of the event, it is very unlikely that any injury will be seen.
The hymen
[16]The hymen is an anatomical structure situated just inside the vaginal canal, which will be ruptured if an object of sufficient size is pushed into the vagina. The hymen varies in appearance, thickness, elasticity and shape. It may be an extremely fine membrane, which ruptures very easily; or, rarely, it may be a rigid, thick, membrane that requires surgical division before any object can be placed into the vagina. A young woman with the latter type of hymen, for example, will not be able to insert tampons during her periods. If a young woman, with this unusual type of hymen, is sexually assaulted she may suffer a tear of the perineum similar to the effect of childbirth.
[17]The hymen normally has an opening through which the period flow is able to escape after the onset of puberty. The size of the opening varies from very small to fairly large. The hymen also alters in appearance, thickness and elasticity under the influence of female hormones, which increase in amount dramatically as the child approaches puberty. The increasing elasticity is physiologically designed to make the penetration of the hymen easier in preparation for the commencement of consensual sexual activity.
[18]It is possible for a young woman to have partial penetration of the vagina when physically and sexually mature with little damage to the hymen, if the hymen is of the type that is folded and elastic. However, there will usually be some disruption of the hymen, seen as a healed transection extending to the vaginal wall, if full penile penetration has occurred.
[19]In examining a hymen which has been transected or ruptured, it will not be possible to state when the injury occurred unless the examination is done within a few days of the event. The edges of the rupture will heal rapidly and the transection that remains could be a week old or a year old without a difference in appearance.
[20]In most instances, a pre-pubertal child will not suffer a full penetrative act into the vagina and the penis will be placed sideways into the genital area across the opening of the vagina, leaving no physical evidence of penetration. If full penetration does occur in a very young pre-pubertal child, she will probably suffer severe genital injury requiring surgical repair. Partial penetration, by fingers, narrow objects and the tip of the penis may cause minor disruption of the hymen tissue. Unless an examination takes place within 24–48 hours of such an event, it is not possible to state, from the examination findings, when the penetration took place.
Anal sexual assault findings
[21]Anal sexual assault may occur in adults and children, and in females and males. Because the anus is anatomically designed to allow for the evacuation of bowel products, it is able to expand to a surprisingly large extent in both adults and children. It has an extremely good blood supply, which means that injuries to the anal canal almost always heal extremely rapidly and without scarring.
[22]In anal sexual assault the penetration is usually rapid and is frequently done without the use of lubricant. Anal penetration in the course of a sexual assault is invariably described as painful and is frequently accompanied by some bright bleeding. If an examination is done within the first 24 hours, it may be possible to see linear abrasions in the anal canal. It may also be possible to see blue discolouration caused by bruising of the anal verge or the entrance to the anal canal. However, if the examination is delayed to 48 hours after the sexual assault, it is likely that these findings will have disappeared and the anal canal and verge will appear normal.
[23]There is no structure similar to the hymen in the anal canal and, consequently, anal assault is difficult to diagnose from an examination. Also, severe constipation may cause linear anal abrasions similar to those caused by a penetrative assault.
Use of medical findings
[24]The medical findings from an examination performed fairly soon after a sexual assault may be extremely important forensically or may be almost totally irrelevant. Consensual sexual intercourse can cause genital injuries if it is the first act of intercourse, if it occurs after a long period of abstinence or if there are anatomical difficulties. Non-consensual sexual intercourse may leave no evidence of trauma to substantiate the claim of sexual assault. The medical examination and its findings — the absence or presence of semen, and the absence or presence of trauma — are only one small part of the investigation of a sexual assault matter. Medical evidence must be given due weight. But the absence of injuries does not mean that a sexual assault has not taken place. Similarly, the presence of injuries does not prove that a sexual assault has occurred.
[25]It behoves the forensic physician who conducts these examinations to be accurate, careful, knowledgeable and, above all, objective. They must convey their information in a manner that can be readily understood by the members of the court, so that the court can place the appropriate weight on that evidence.
*MB BS (Syd) MACLM Grad Dip For Med (Mon) Co-ordinator, Medical Services in Sexual Assault, Northern Sydney Health, Royal North Shore Hospital. Medical Services in Sexual Assault provides clinical and forensic services to adults and children.