Sexual Offences - Notes from your prescribed text book "Introduction to Medico-Legal Practice"

1.       Rape

·       Rape (The crime of rape in South Africa is defined by Criminal Law (Sexual Offences and Related Matters) Amendment Act 32 of 2007. It falls under the broad category of sexual offences, which includes sexual assault, incest, bestiality and flashing, among other crimes.

·       South Africa’s legal definition of rape is very broad. The act states that “any person (‘A’) who unlawfully and intentionally commits an act of sexual penetration with a complainant (‘B’), without the consent of B, is guilty of the offence of rape”. This includes the oral, anal or vaginal penetration of a person with a genital organ, anal or vaginal penetration with any object and the penetration of a person’s mouth with the genital organs of an animal.

-         Sexual offences include rape and a variety of so-called ‘‘unnatural offences’’ such as sodomy, incest, bestiality and masochism.

-         Of these rape is the most frequently reported, and the medico-legal investigation of the victims and assailants forms one of the most frequent and important tasks of the district surgeon.

-         The use of drugs to induce amnesia and also to suppress the level of consciousness, has become more popular during the last few years, particularly with so-called ‘‘date rape’’.

Medical examination

Interpretation of clinical findings

·       - Extragenital injuries

·       - Genital injuries

·       - Laboratory test results

·       - General considerations

- The medical examination should commence as soon as the complainant (or a representative) has given consent.

·       The examination must be thorough, taking particular note of even the most trivial of injuries, as well as the mental state of the victim.

·       The appropriate specimens (eg vaginal smears, blood, pubic hair) must be routinely taken. It is often only much later, and usually at the trial, that the relevance of a particular observation or laboratory result relating to the victim or assailant is revealed. It is important to bear in mind that bruising may only appear some hours after the assault.

·       It is equally important to examine the alleged assailant thoroughly, both with regard to his physical and his mental state.

·       The examining doctor will not be in a position to say whether the complainant was raped from the medical findings alone.

·       Although the very nature of the investigation demands a sympathetic approach, his or her function is to report objectively on the observations and to prepare him/ herself adequately to interpret these during evidence, avoiding at all stages and at all costs prejudgment of the case.

·       Note that section 335B of the Criminal Procedure Act 51 of 1977 contains special provisions enabling a magistrate or, in cases of extreme urgency, even a policeman, to consent to medical examination of a minor who was probably a victim of a sexual offence. This may occur where, for example, a parent cannot be traced within a reasonable time, or unreasonably refuses to consent, or is himself or herself the suspected offender, or is deceased.

Interpretation of clinical findings

-        Injuries:

·       No observable injuries were recorded in 33% of cases;

·       Tenderness and abrasions of the genitals in 37%;

·       Genital tears in 25%, and

·       Severe genital lacerations with or without extra-genital traumatic lesions in 5%.

·       Seventy-three per cent of the victims were allegedly assaulted by a single assailant.

Interpretation of clinical findings

·       - Extragenital injuries

·       - Genital injuries

·       - Laboratory test results

·       - General considerations

 

- Extra-genital injuries

-         The absence of signs of injury on the complainant’s person should not be construed as consent to sexual relations.

-         She may have been overcome by fear, submitted under threat of harm to her children or partner, or had been heavily intoxicated.

-         In gang rapes, where the victim is overcome by a number of assailants, or if attacked from the back by a single person, it may be very difficult to offer any resistance.

-         Furthermore the victim may be examined shortly after the event, in which case bruising, which may only appear many hours later, is not evident.

-         It is therefore sometimes indicated that the person must be re-examined 24 hours later.

-         Conversely, although the presence of injuries suggests that force was used to overcome resistance — and the more extensive they are the more likely this is to be the case — it should be borne in mind that the injuries may be unrelated to the rape as such, the allegation of rape being part of a trumped-up charge.

-         The occasional bruise, nail scratch or bite mark is not infrequently inflicted during over-zealous intercourse with consent. This includes a so called love-bite.

-         It is also important to examine the finger nails for any foreign material.

 

- Genital injuries

-         In the case of a marked disproportion in size between the assailant and the victim (eg when a child was assaulted) the injuries to the genital organs may be extensive and extend into the abdominal cavity and rectum.

-         If the victim had borne children, no injuries may be detected in or about the vagina, despite the fact that force was used to penetrate the vagina.

-         The presence of an intact hymen, depending on the type of hymen, is not necessarily an indication of virginity. Neither is it an indication that rape has not taken place.

-         On occasion, rape is associated with other abnormal sexually perverse acts such as sodomy, fellatio lingua (oral stimulation of the sexual organ) and genital mutilation.

 

Laboratory test results

-         The results concerning injuries related to sexual assault should be evaluated just as critically as test results from any other type of injury.

-         What the analyst conveys to the reader should be what is read into the report, purely and simply, namely that from the specimen a certain result was elicited. In evaluating this finding relative to the subject under review the reader must determine whether the following was carried out:

. The specimen submitted for analysis was drawn properly.

. It was adequately preserved in transit.

. It was suitably identified.

. It was not contaminated before or after collection.

. It was representative of the subject matter under consideration.

In addition, the method of testing should be known to the reader, and its accuracy, specificity and the ability to reproduce it, understood.

-         Molecular biology and the use of DNA analysis has made it much easier to identify an assailant. In the case of DNA typing the result can prove beyond any doubt that a single hair, drop of blood, sperm, minute fragment of tissue, et cetera, is derived from a particular person.

-         This specificity, which makes it possible to determine a person’s identity almost 100% accurately, is due to the uniqueness of each individual’s nucleic acid (DNA) structure of the cell, and hence the many different permutations of each of these characteristics in any one individual.

 

General considerations

-         Ejaculation may have occurred in the anus or on the perineal surface.

-         Where no ejaculation has occurred, despite penetration, there may be a considerable amount of secreted penile (urethral) mucous which the woman may mistake for ejaculate.

-         Intense emotion or depressants such as alcohol or drugs may inhibit ejaculation.

-         The presence of smegma (secretion) below a free prepuce (foreskin) suggests that the male has not had intercourse for some days.

-         During sexual intercourse, where there is marked disproportion in the sexual organs, the male may rupture the frenular artery, which passes below the head of the penis, and it may bleed profusely. In intercourse with consent this may be a source of considerable embarrassment to both parties, and a revelation to a third party.

-         In studying the topic of rape it is important to bear in mind that mere contact, for example when the penis is placed on the vulva, constitutes penetration. Penetration, therefore, does not necessarily involve penetration of the hymen.

The following examples should clarify this point:

1. Strips of hymenal tissue may still be present in women who gave birth vaginally.

2. The hymen of the non-virginal non-parous (ie not giving birth) woman, depending on the type of hymen, generally reveals an old rupture at the mid-posterior position.

3. A ruptured hymen may be the result of masturbation, and the hymen may bleed profusely.

4. Non-virginal women may have intact hymens, particularly of the annular type. Cases have been reported of prostitutes where this type of hymen revealed no evidence of having ever ruptured. Spermatozoa may be found in the vagina for as long as five to ten days after being introduced there. Although motile spermatozoa can retain their motility for as long as five to ten days after being introduced into the vagina, this period is reduced to no more than an hour or two in the majority of cases.

The absence of sperm in the vagina does not mean that there was no ejaculation into the vagina. This absence may be the result of a zoospermia (absence of sperm) in the ejaculate, or the use of a condom.

 

 

Firearm Injuries - Notes from your prescribed text book " Introduction to Medico - Legal Practice"

Introduction

 

- firearms include arms that can fire plastic and rubber bullets, industrial nail guns, pistols, revolvers and rifles

- This group of firearms is divided into:-

*      hand arms and shoulder arms and also

*      according to whether the barrel is rifled or not.

 

- Rifled firearms have spiral grooves on the inner surface of the barrel which gives the spinning movement to the projectile as it travels down the barrel. This rotational movement or spin stabilizes the projectile in flight.

- Hand arms for example:-

* revolvers and

* pistols, as well as

* shoulder arms such as hunting rifles, and

* automatic and semi-automatic machine guns, all have these grooves.

 

-Smooth-bore firearms (eg shotguns) do not have grooves.

 

What happens when firing a firearm?

- When the striking pin activated by the trigger strikes the striking cap, the spark generated ignites the propellant powder in the bullet casing.

- This powder has chemical and physical characteristics peculiar to the type of ammunition.

-The gases which develop during the explosion have a potential volume many times greater than that of the powder, generally in excess of 500 times under atmospheric pressure.

- It is this gas pressure which drives the projectile along the barrel. While passing along the barrel the projectile is soiled by oil and gas in the barrel. When it leaves the muzzle there is also a flash and a gas emission, which includes carbon monoxide, as well as hot and partially unignited powder particles, all of which impart to the recipient surface characteristics which assist in determining the firing range for that particular weapon and its ammunition.

 

 Medical Examination

- The medical practitioner - the observations made in the case of firearm injuries can be of considerable assistance:-

* in establishing the range

* as well as the direction of fire,

* the type and caliber of weapon and

* the nature of the wound, for example whether it points at suicide, homicide or an accident,

* the manner of death as well as the

* period of survival and the extent of immobilization of the victim.

 

- In order to measure up to the expectations of the court in this regard, close attention must be paid to the size and shape of the entrance and exit wound(s).

 

* Careful inspection of the skin around the entrance wound, noting the presence, size and shape of any abrasion collar, smoke blackening, tattooing and singeing of hair, is an essential element of the medical investigation.

* Evidence should also be sought of any vital reaction, such as erythema (a reddening of the skin) in the vicinity of hot-powder tattooing.

* An X-ray examination of the body (both at the clinical examination and the autopsy) can be of considerable assistance in retrieving projectiles for ballistic examination, particularly in the case of multiple entrance wounds.

* In siting both entrance and exit wounds it is helpful if measurements are expressed as the perpendicular height above the base of the heel line.

* Entrance and exit wounds must preferably be indicated on a diagram. This can assist (when evidence is given) to relate the findings to circumstantial evidence.

* It must be remembered that the direction of the wound track, with the body in the anatomical position during the post-mortem examination, is not necessarily representative of the position of the body when it was hit by the projectile.

 

·    In shotgun injuries, especially those inflicted at close range, the total mass of the individual projectiles is a very important factor in the kinetic energy equation.

·    At close range the pellets act as a solitary missile because of tight clustering, and their total weight is much greater than that of individual rifle or handgun bullets. Furthermore, the ballistically poor design of multiple small, round balls does not favour maintenance of high kinetic energy at considerable distances from the muzzle, nor does it permit great tissue penetration.

·    However, at close ranges (ie up to about 3 m in the case of shotguns) the energy release generally causes massive tissue disruption close to the point of penetration. For this reason close-range shotgun injuries have many of the characteristics of high-velocity missile war wounds.

 

·      When a missile enters tissue a temporary pulsing cavity, in which the tissues swell and stretch and compress, is formed along the missile tract within 10 to 30 milliseconds after impact. This cavity can be as large as 30 to 40 times the diameter of the bullet. This phenomenon that has been seen in muscle, liver, bone, brain, lungs, and arteries is Caused by energy released by the missile, forming shock waves with pressures of up to 100 to 200 atmospheres directly related to missile velocity, and imparting momentum to the tissues, both forward and laterally.

·     In addition there is mechanical damage due to the shearing effect between tissues of differing heterogeneity and density. The actual cavity created by the missile rapidly collapses behind the projectile as a result of tissue elasticity, haemorrhage leaving a smaller permanent pathway usually marked by tissue loss,  haemorrhage, bullet fragments or sometimes bone fragments which can be seen during radiological examination shortly after injury.

·     Bullet fragmentation is a major cause of tissue disruption and there is a close connection between large exit wounds and bullet fragmentation. The critical velocity at which bone is fractured is approximately 66 m/s. Kinetic energy imparted to the tissue causes bone to fracture. Although some bone fragments may be contained within the surrounding framework of the periosteum (bone membrane), muscle and connective tissue, others may have sufficient energy to act as secondary missiles, creating further destruction and multiple exit-wounds.

·      The medical examiner may thus be faced with a discrepancy between the number of entrance and exit wounds. In low-velocity gunshot wounds, defined as those inflicted by missiles travelling at a velocity of less than 360 m/s (ie most handguns), the energy transferred to the tissues is considerably less than that of high-velocity missiles, resulting in less tissue destruction.

 

 

Cutaneous (skin) entrance wounds caused by rifled firearms

 

-       Entrance wounds are usually round or ovoid (oval) with an abrasion ring where the bullet abraded the skin during entrance.

-       This abrasion ring is caused by the force exerted by the projectile at entry, when the outermost layers of the epidermis are stripped away. It is not caused by the rotational movement of the projectile, as it is sometimes described in the literature, but by the tangential force exerted on the skin.

-       Similar abrasions are sometimes seen surrounding the exit wound when the skin is pressed against a hard object, for instance a belt buckle.

-       After the bullet perforated the skin the elasticity of the cutaneous tissue restores the skin's previous elasticity and the skin defect contracts.

-       When bullets strike skin at a 90 degree angle (ie perpendicular to the skin surface) they produce round entrance wounds with a more or less symmetrical collar or abrasion ring.

-       Oval or elliptical entrance wounds with asymmetrical abrasion rings occur when bullets strike the skin at acute angles. The wider area of abrasion is then located on the side of the entrance wound closest to the gun.

-       Entrance wound shape (ie round, oval, star-shaped or cross-shaped) and size must be described precisely.

-       Cutaneous injury and its associated features, such as soiling and rim abrasion ring, should be accurately measured and the dimensions recorded.

-       A circular wound requires only the diameter measurement, whereas an elliptical (oval) wound is measured across its widest and narrowest diameters and variations in width of the marginal abrasion are recorded.

-       Marginal dotting due to unburnt powder residues should be specifically noted.

 

 

 

 

 

 

Tattooing due to burnt, unburnt and partially burnt gun powder particles

Smoke (soot) deposits

Singeing of hair due to heat

Abrasion ring surrounds central entrance defect. The abrasion ring is the result of trauma to the skin due to radial forces which act on the skin as it is pierced by the projectile/bullet Sometimes oil, etc is also seen on the inner aspect

Central defect. This can have a smaller diameter than the bullet, due to stretching of the skin

 

Contact wounds

- The margins of the skin perforation are charred by the flame coming from the muzzle, and the abraded border is usually soiled with powder residue which can also be clearly visible in the subcutaneous and deeper tissues.

- The surrounding abrasion ring is of uniform width, and around this there can be an additional abrasion ring from the gun barrel and gun sight.

- These muzzle imprints result from expansion of the dermal tissue when gas is blown into the tissue, elevating the skin surface and pressing it tightly against the muzzle.

- The dermal tissues in and immediately adjacent to the bullet track may have a cherry red colour due to localised carboxyhaemoglobin formation from carbon monoxide in the muzzle gases. If the muzzle is at an angle with the skin, the distribution is more elliptical.

- Contact-range entrance wounds in the scalp look slightly different because stellate (star-shaped) lacerations radiate from the central defect. This is due to expansion of the explosion gases between scalp and skull and within the cranial cavity. Explosion skull fractures may result, producing bone fragments which can act as secondary missiles.

 

 

Intermediate or medium distance entrance wounds

- Entrance gunshot wounds are classified as intermediary when muzzle-to-target distances are such that the target surface is still within range of the muzzle blast although target and muzzle are not in contact. Maximum muzzle-to-target distances at which flame and muzzle blast create dermal damage and soiling vary according to the type of gun and ammunition.

- Handguns and ammunition encountered in civilian homicides do not ordinarily deposit powder on the target at ranges greater than 50 to 75 cm.

- Close-range entrance wounds in unclothed areas may be surrounded by a radial arrangement of soot and be singed by flame. If the wound is in a hairy area, hair may be singed and examination with a hand lens may reveal clubbing of the hair ends due to melting of the keratin.

 

 

Distant wounds

A distant wound may show a surrounding faint zone of discoloration due to dermal bleeding. Only the defect where the bullet entered the skin, with a surrounding abrasion ring, is evident.

 

Cutaneous gunshot exit wounds caused by rifled firearms

- These are produced by a stretching force applied to the skin from its undersurface with perforation of the dermis and epidermis when their limits of elasticity are exceeded. The surface defects vary widely in shape and configuration and may be stellate, cruciate, round, elliptical, crescentic or linear cutaneous-lacerations.

- The greater the missile's velocity when it exits, the larger and more jagged the exit wound. Skin edges are often everted (inside-out) and shreds of contused (bruised), haemorrhagic subcutaneous fat may extrude through the defect. Characteristic features of dermal entrance wounds such as the marginal abrasion ring, soiling and burning, are absent from exit wounds, with the exception of those located over a part of the body which lies beneath or is pressed against a firm surface such as a leather belt, a wall or the ground. In these cases a marginal abrasion ring may surround the exit wound.

 

-    Exit wounds are usually larger than entrance wounds, provided the latter had not been affected by expanding explosion gases. Two factors, acting either individually or together, are usually responsible for the greater size of exit wounds. The first factor is tumbling of the missile, which increases the chances of it leaving the body with an oblique surface presented at the striking area. The missile is thus turned sideways, and does not move forward head first. The second factor is bullet deformation due to it striking some hard object such as bone, which causes consequent flattening of and an increase in missile diameter, a type of change especially common in soft-nosed and hollow-nosed projectiles.

 

-     When the examiner is confronted with a single entrance wound and multiple exits, the possibility of bullet and/or bone fragmentation should be considered. If the shot was fired from beyond the range at which tattooing would occur it can be difficult to differentiate between an entrance and exit wound. If the projectile passes through bone, and particularly the skull, the direction can be readily determined, since the entrance into the bone will be sharply cut and about the same diameter as the projectile. On the inner table the bone will exhibit a bevelling (sloping) effect and the defect in the bone will be generally larger than that at the entrance. The bone breaking away from the inner table will produce secondary missiles which may cause more extensive tissue damage than the missile itself. As the projectile leaves the skull the converse will apply, that is the wound on the outer table will be bevelled.

 

Gunshot wounds caused by smooth-bore firearms (shotguns)

These wounds merit a separate discussion because shotguns and their ammunition differ so markedly from rifled weapons and their ammunition. As mentioned above, range, gauge (barrel diameter), degree of ``choke'' and size and number of pellets in the shell play a role in determining the characteristics of shotgun injuries.

-The explosive effect and the burns created by the muzzle flame can cause additional damage to the damage created by the shot if gun and victim are sufficiently close.

- Additional trauma may result from the padding striking the victim, a feature not seen in other types of firearm injuries.

Contact and close-range cutaneous shotgun entrance wounds are round or elliptical, depending on the angle between muzzle and skin. Smoke and powder residue with scorching, surround the entrance wound, and marginal abrasion similar to a single-bullet entrance is present. Occasionally, stellate lacerations due to the muzzle blast are seen as gases expand beneath the skin and lacerate the wound edges as they exit through the original entrance.

Contact shotgun wounds of the head commonly cause extreme mutilation.

With close-range shots of up to 120 to 150 mm the shotgun charge enters the body as a single conglomerate mass producing a round defect somewhat larger in diameter than the bore of the barrel. Wound margins in such cases show abrasion as well as scalloped defects. The linear abrasions occasionally seen in the immediate vicinity of these wounds are due to the impact of clothing against the stretched skin during penetration of the shot.

 

Beyond this range, as muzzle-to-target distance increases, the major central defect becomes progressively smaller and individual pellet wounds become more numerous as the pellets begin to fan out. However, the minimal distance at which this occurs varies considerably, ranging from 90 to 120 mm with sawn-off shotguns, 180 mm with cylinder-bore guns and up to 540 mm with

full-choke guns. Wadding and plastic casing usually enter the wound when muzzle-to-victim distance is less than 150 to 180 mm. As a rough estimate it is usually accepted that for every meter the pellets will disperse 2,5 to 3,0 cm. If the diameter of the wound (the maximum distance between the most remote pellet wounds on the skin) is therefore 30 cm, the firing distance was approximately 10 meters.