Forensic Medicine 2025 PDF

FACULTY OF MEDICINE 2025 FORENSIC MEDICINE LECTURER DR. ABDULLAH AL-SAFY Forensic medicine Wounds DR/ABDULLAH EL SAFY 2025 FORENSIC MEDICINE DR/ABDULLAH EL SAFY Mechanical injury (Wounds) DEFINITION: Any injury (Int...

FACULTY OF MEDICINE 2025 FORENSIC MEDICINE LECTURER DR. ABDULLAH AL-SAFY Forensic medicine Wounds DR/ABDULLAH EL SAFY 2025 FORENSIC MEDICINE DR/ABDULLAH EL SAFY Mechanical injury (Wounds) DEFINITION: Any injury (Interruption in continuity of tissue) occurring to the body either internal or external due to application of mechanical force can be defined as wound. Classification A. LEGAL CLASSIFICATION (ACCORDING TO SEVERITY): SIMPLE WOUND DANGEROUS WOUND FATAL WOUND A wound which heals in A wound which heals in A wound which causes death less than 20 days more than 20 days. immediately or later on due to without permanent infirmity leaves permanent infirmity. its complications. PERMANENT INFIRMITY DISFIGUREMENT Loss of functioning organ or loss loss of non-functioning organ or of its function either partial or spoil the appearance or shape of complete. certain part of the body. B. MEDICO-LEGAL CLASSIFICATION (ACCORDING TO SHAPE): 1. ABRASIONS. 4. CUT WOUNDS (INCISED WOUNDS) 7. FABRICATED WOUNDS 2. CONTUSIONS (BRUISES) 5. STAB WOUNDS 3. CONTUSED WOUNDS. 6. FIREARM WOUNDS 1  FORENSIC MEDICINE DR/ABDULLAH EL SAFY ABRASIONS DEFINITION: Abrasions are the simplest form of wounds which are destruction of superficial layer of the skin due to friction against rough surface. TYPES SCRATCHING ABRASION. SLIDING (GRAZE) ABRASION Caused by sharp or pointed instrument Caused by friction between the skin passing across the skin. and hard rough wide surface. IMPACTION ABRASION. PRESSURE ABRASION. Caused by sharp pointed instrument when caused by direct pressure of rough force applied perpendicular to skin. heavy object over skin with crushing epidermis. MEDICO-LEGAL IMPORTANCE OF ABRASIONS: 1. SHAPE : Gives an idea about the causative instrument. ➤ Fingernail abrasions: Small semilunar abrasions. ➤ Human bite abrasions: Two curved rows، small abrasions meeting each other. ➤ Rope abrasion: When rope is tied on skin, it will produce abrasion which takes same pattern of rope. 2. SITE : Gives an idea about the type of the crime. ➤ Fingernail abrasions: Around the mouth and nostrils »»» Smothering. Around the neck »»» Throttling. At the inner sides of the thighs of young female »»» Rape. ➤Human bite abrasions at breasts of young female »»» Rape. ➤ Rope mark abrasions: Around the neck »»» Hanging (High and oblique). »»» Strangulation (Low-down and transverse). 2  FORENSIC MEDICINE DR/ABDULLAH EL SAFY 3. TIME : Help in the identification of certain crimes. The age of wound (Degree of healing or sepsis) must be coinciding with the date of the crime. New abrasion : Red - Tender - Raw surface with serous fluid oozing from it After 2 days : oozing serum dries and forms reddish brown soft scab covers raw surface. After 4 day : scab becomes gradually dry and darker in color (Brown). After 6 days : scab falls off leaving a pink surface with thin new layer of epithelium (The new epithelium gradually takes the same color of the surrounding skin) 4. ANTE MORTEM OR POSTMORTEM ABRASIONS: ANTE MORTEM POSTMORTEM Surrounded by hyperemia. There are underlying bruises. There is cellular infiltration. Presence of signs of sepsis. Presence of signs of healing. Color changes are present. Causes of postmortem abrasions: Dragging of the dead body on rough surface. Eating of superficial skin layers by ants and rodents. Soaking of the skin with urine or stool. Falling of the epidermis after putrefaction. CONTUSIONS (BRUISES) DEFINITION: Contusion is subcutaneous haematoma due to rupture of subcutaneous blood vessels and extravasation of blood as a result of trauma by heavy blunt instrument. TYPES Traumatic. Pathological: Diseases of blood vessels (Atherosclerosis). Blood diseases (Hemophilia - Purpura). 3  FORENSIC MEDICINE DR/ABDULLAH EL SAFY FACTORS AFFECTING CONTUSIONS: 1. Severity of the trauma: The more severe the blow the more extensive the size of bruise. 2. Type of tissue affected (Site of trauma): Bruises develop more easily in vascular, lax. and soft t issues such as eye lids than less vascular tough tissues as that of the palms of hands and soles of feet. 3. Bony support: Tissues supported over bones are bruised more easily than unsupported tissues due to compression and damage of more subcutaneous blood vessels. 4. Age: Children and elderly are bruised more easily than adults because of their softer tissue and thin skin. 5. Sex: Females are bruised more easily than males, because male skin is thicker with tough subcutaneous tissues. 6. General health: Patients with hemorrhagic blood diseases are bruised more easily with mild trauma than healthy persons. MEDICO-LEGAL IMPORTANCE OF CONTUSIONS: 1. SHAPE : Gives an idea about the causative instrument. ➤ Fingernail Contusion: Small rounded bruises. ➤ Human bite Contusion : Two curved rows، small Contusion meeting each other. ➤ Rope Contusion: When rope is tied on skin, it will produce Contusion which takes same pattern of rope. 2. SITE : Gives an idea about the type of the crime. ➤ Fingernail Contusion: Around the mouth and nostrils »»» Smothering. Around the neck »»» Throttling. At the inner sides of the thighs of young female »»» Rape. ➤Human bite Contusion at breasts of young female »»» Rape. ➤ Rope mark Contusion: Around the neck »»» Hanging (High and oblique). »»» Strangulation (Low-down and transverse). In some cases contusion may be produced away from the site of the trauma. Blow on the forehead may produce bruise in and around the eyelids (Black eye) because, blood will track between muscle layers of frontalis muscle, consequently blood collects downwards around the eye along the orbicularis oculi muscle fibers. Blow on the calf muscle may produce bruise around the ankle because, blood will track between muscle layers and collects downwards around the ankle joint. 4  FORENSIC MEDICINE DR/ABDULLAH EL SAFY 3. TIME : Help in the identification of certain crimes. The age of wound (Degree of healing or sepsis) must be coinciding with the date of the crime. Age of bruise is estimated by color changes caused teb by enzymatic action of macrophages and action of histocytes on haemoglobin. New contusion: Bright red color due to oxy haemoglobin. After 2 days: Blue color due to change to reduced haemoglobin. After 4 days: Green color due to change to biliverdin. After 6 days: Yellow color due to change to bilirubin. After 4 weeks: Normal skin color because pigments are removed by histocytes Subconjunctival hemorrhage remains red till it is completely absorbed by histocytes because the haemoglobin being kept oxygenated 4. ANTE MORTEM OR POSTMORTEM CONTUSION: 5.MAY BE MISTAKEN WITH HYPOSTASIS ANTE MORTEM POSTMORTEM BRUISE HYPOSTASIS Surrounded by hyperemia Surrounded by hyperemia. There is cellular infiltration. There is cellular infiltration. Presence of signs of sepsis. Presence of signs of sepsis. Presence of signs of healing. Presence of signs of healing. Color changes are present. Color changes are present. Punching blow with the clenched fist. At the upper part of the body. Most commonly abrasions and bruises. Fracture nose or detached teeth are common. It is not serious except in children as rupture intestines or liver may occur Kicking blow with the foot. At the lower part of the body. Most commonly abrasions and contusions. More serious than punching due to injury to deep abdominal organs. Bite marks. (Teeth abrasions and contusions) Any where in case of child abuse or fight. On the neck or breasts with sexual crimes (Love bites). Bites should be rubbed with swab to obtain saliva for identification of blood group of assailant. 5  FORENSIC MEDICINE DR/ABDULLAH EL SAFY CONTUSED WOUNDS DEFINITION: Contused wound is an open wound due to trauma by heavy blunt instrument. TYPES ➤ Ordinary contused wound. It is produced by heavy blunt instrument. ➤Flap contused wound (Torn). Patern It is produced by running belt of machine. ➤ Crush contused wound. It is produced by vehicle running over body causing crushing of tissues. ➤ Lacerated contused wound. It is produced by sharp fragment of bone when bone is fractured and sharp bone fragment is pushed through skin from inside. CHARACTERS OF CONTUSED WOUNDS: Base Irregular, tissue bridges. Gaping Irregular, no wide gaping due to bridging of tissue. Angles Irregular multiple angles. Edges Irregular edges. Hair Crushed (Examined by hand lens). Bleeding Minimal because vessels are crushed but closed. Abrasions Present around the edges. Contusions Present around the edges. Sepsis There is great liability for sepsis. Healing Delayed by secondary intension. MEDICO-LEGAL IMPORTANCE OF CONTUSED WOUNDS: 1. SHAPE : Gives an idea about the causative instrument (Heavy blunt). 2. SITE : Not significant. 3. TIME : No role for healing by secondary intension. 6  FORENSIC MEDICINE DR/ABDULLAH EL SAFY 4. ANTE MORTEM OR POSTMORTEM CONTUSED WOUNDS. ANTE MORTEM POSTMORTEM Surrounded by hyperemia. There are underlying bruises. There is cellular infiltration. Presence of signs of sepsis. Presence of signs of healing. Color changes are present. Contused wound may appear like cut wound. this occurs when contused wound affects the skin which is overstretched directly on bone (Skull - Tibia). Differentiation will be easy by examination of edges of wound by a hand lens which will show crushed hair and irregular characters of contused wound. CUT WOUNDS(INCISED WOUNDS) DEFINITION: Cut wound is an open wound produced by drawing the edge of a sharp instrument along the surface of the tissue. CHARACTERS OF CUT WOUNDS: Base regular, no tissue bridges. Gaping regular, wide gaping with no bridging of tissue. Angles regular 2 acute angles. Edges regular, sharp edges. Hair Sharply cut (Examined by hand lens). Bleeding Excessive because All vessels are cut. Abrasions Not Present. Contusions Not Present. Sepsis less liability for sepsis. Healing Rapidly by primary intension. 7  FORENSIC MEDICINE DR/ABDULLAH EL SAFY MEDICO-LEGAL IMPORTANCE OF CUT WOUNDS: 1. SHAPE : Cives an idea about the causative instrument (Sharp edged). 2. SITE : Gives an idea about the type of the crime whether homicidal, suicidal, accidental or fabricated. ➤ Homicidal: Homicidal cut wounds may be seen over any part of body such as nose, ears and genitalia. ➤ Suicidal: Suicidal cut wounds are usually found on certain sites of selection on accessible parts of the body such as front of wrist and neck (Cut throat). ➤ Accidental: Accidental cut wounds may be seen over any part of the body. ➤ Fabricated: Fabricated cut wounds usually present in a safe area of the body such as upper and lower limbs. 3. TIME : Help in the identification of certain crimes. The age of wound (Degree of healing or sepsis) must be coinciding with the date of the crime. ➤First day: ◆ Red swollen edges with blood clot. ➤ After 3 days: ◆ Complete capillary network is formed. ◆ New blood vessels grow from the deeper layers. ◆ Pus may present if sepsis occurred. ➤After 6 days: ◆ Obliteration of blood vessels. ➤ After 9 days: ◆ Wound heals by primary intention. ➤ After 1 month: Red scar is formed. ➤After 3 months: Coppery scar is formed. ➤ After 6 months: Pale scar is formed 8 FORENSIC MEDICINE DR/ABDULLAH EL SAFY 4. ANTE MORTEM OR POSTMORTEM CUT WOUNDS. ANTE MORTEM POSTMORTEM Surrounded by hyperemia. There is cellular infiltration. Presence of signs of sepsis. Presence of signs of healing. Color changes are present. 5.MAY BE MISTAKEN WITH COUNTUSED WOUND items Cut Wound Countused Wound Base regular. irregular. Gaping regular. irregular. Angles regular. irregular. Edges regular irregular Hair Sharply cut crushed Bleeding Excessive minimal Abrasions Not Present. Present. Contusions Not Present. Present. Sepsis less liability for sepsis. More liability for sepsis. Healing primary intension. Secondary intension. The cut wound may appear like contused wound is seen when the cut wound affects loose corrugated skinas in axilla or scrotum differentiation will be easy by examination of edges of the wound by hand lens which will show regular characters of cut wound 9  FORENSIC MEDICINE DR/ABDULLAH EL SAFY STAB WOUNDS DEFINITION: Stab wound is an open wound produced by sharp pointed instrument pushed into the body in stabbing manner. TYPES ➤ Ordinary stab wound: A stab wound caused by sharp edged and pointed instrument (knife) ➤Puncture stab wound: A stab wound caused by sharp pointed instrument with no sharp edge (Nail). ➤Perforating (Penetrating) stab wound: A stab wound reaches a body cavity. ➤Transfixing stab wound: A stab wound passes from side to the opposite side. CHARACTERS OF STAB WOUNDS: Base regular, no tissue bridges. Gaping regular, wide gaping,No bridging of tissue. Angles regular and take shape of instrument. Edges regular, sharp edges. Hair Sharply cut (Examined by hand lens). Bleeding Excessive because All vessels are cut. Abrasions Not Present. Contusions Not Present. Sepsis More liability for sepsis. Healing Delayed by because the stab can reach internal organ. width Width =Breadth of the weapon. Depth Wound more deep than wide. Never try to identify the weapon by reintroducing it into the wound because this may lead to permanent changes in the shape and size of the wound. 10  FORENSIC MEDICINE DR/ABDULLAH EL SAFY MEDICO-LEGAL IMPORTANCE OF STAB WOUNDS: 1. SHAPE : Cives an idea about the causative instrument (Sharp edged). ➤Sharp pointed instrument (Nail): The wound is rounded. ➤Single-edged instrument (Knife): One angle of the wound is acute, other is rounded. ➤Double-edged instrument (Dagger): The two angles of the wound are acute. ➤Closed scissor: The wound is rhomboid. 2. SITE : Gives an idea about the type of the crime whether homicidal, suicidal, accidental or fabricated. Homicidal: Homicidal stab wounds may be seen over any part of body but usually seen over the neck, chest, and abdomen. Suicidal: Suicidal stab wounds are usually found on certain sites of selection on accessible parts of the body such as chest and abdomen. Accidental: Accidental stab wounds may be seen over any part of the body. Fabricated: Fabricated stab wounds usually present in a safe area of the body such as upper and lower limbs. 11  FORENSIC MEDICINE DR/ABDULLAH EL SAFY Differences between homicidal, suicidal and accidental stab wounds: items homocidal Suicidal Accedintal History of: History of: 1. Circumstantial Having enemies. Financial troubles evidence History of Accident Causing disgrace to family. Failure in love or exam. Door closed from outside. Door closed from inside. Disturbance of furniture. Previous attempts of suicide. No letter is left. Letter may be present 2. Sex Any sex Usually male Any sex evidence of struggle as tears Present with no 3. Clothes May be removed before evidence of when stabbing follow a quarrel struggle 4. Cadaveric spasm Not present and weapon is Present on the weapon Not present usually not found 5. Weapon Any sharp pointed instrument Usually ordinary knife. Any sharp instrument. 6. Fingerprints Of the assialant Of the suicide Of the User 7. Number of wounds Any number Usually one Usually one Any site Chest Backwards 8. Site and direction Any site Abdomen Backwards 3. TIME: No role for healing because stab wound can reach internal vital organs with excessive internal heamorrhage. 4. ANTE MORTEM OR POSTMORTEM STAB WOUNDS. ANTE MORTEM POSTMORTEM Surrounded by hyperemia. There is cellular infiltration. Presence of signs of sepsis. Presence of signs of healing. Color changes are present. 12  FORENSIC MEDICINE DR/ABDULLAH EL SAFY DEFENSIVE WOUND These results from the victim's spontaneous reaction of self-defense when he is attacked. When the weapon is blunt: There are usually multiple abrasions, contusions or contused wound on the forearm or back of the hand. When the weapon is sharp: The injuries will depend upon the type of attack, weather stabbing or cutting, The injuries will be produced by grasping the instrument with cut wounds across flexors of fingers and finger webs or stab wound on the palm of the victim 13