490 likes | 843 Views
FORENSIC PATHOLOGY. Motor Vehicle Accidents. MOTOR VEHICLE ACCIDENTS. Why perform an autopsy after a MVA? Determine cause of death Confirm death was caused by injury in the MVA Determine extent of injuries Detect any disease or factor which may contribute to MVA
E N D
FORENSIC PATHOLOGY Motor Vehicle Accidents
MOTOR VEHICLE ACCIDENTS • Why perform an autopsy after a MVA? • Determine cause of death • Confirm death was caused by injury in the MVA • Determine extent of injuries • Detect any disease or factor which may contribute to MVA • Document findings for criminal or civil case • Establish positive ID of body
MOTOR VEHICLE ACCIDENTS • Causes of MVA • Impairment of driver is most common • 50% of all crashes are due to DUI of alcohol or drugs • Drugs may be prescription • Even marijuana impairs driving skills • 2nd cause is human error • Speed, reckless driving, falling asleep at wheel • 3rd cause is environmental hazards
MOTOR VEHICLE ACCIDENTS • Four Major Categories of MVA’s in descending order of fatality for automobiles • Front impact • Side impact • Rollovers • Rear impact
MOTOR VEHICLE ACCIDENTS • Four major categories of MVA’s for pickups and utility vehicles in descending order of fatalities • Rollovers • Frontal impact • Side impact • Rear impact
MOTOR VEHICLE ACCIDENTS • Front Impact Crashes • In a head on collision if the driver is not restrained the body will continue its frontal movement • Strike instrument panel at knees • Strike chest on steering wheel • Strike head on windshield of visor
MOTOR VEHICLE ACCIDENTS • Front Impact Crashes • Knees • May have patterned abrasions • Fractures of the patella • Fractures of the femur or hip joint • Especially neck of femur • Exsanguination may occur
MOTOR VEHICLE ACCIDENTS • Front Impact Crashes • Chest • May impact steering wheel or dashboard • Imprinted abrasions/contusions • Internal injuries • Fracture of sternum and/or ribs • Lacerations, contusions, rupture, transection of vital organs • Liver, spleen, heart, aorta
MOTOR VEHICLE ACCIDENTS • Front Impact Crashes • Head • Patterned abrasions • Impact windshield • Windshield does not shatter • Thin outer and inner layers of glass, thick core of plastic • Dicing injuries • Avulsion of skin especially to head • Basilar fractures of skull • Hinge fractures • Fractures of neck • Atlanto-occipital junction dislocation
MOTOR VEHICLE ACCIDENTS • Unrestrained injuries usually occur in sequence • Knee-femur-hip-chest-head • Restrained injuries are dependent on the force of the crash
MOTOR VEHICLE ACCIDENTS • Side Impact Crashes • Broadside at intersections most common • Driver’s side • Head can flex laterally through side window • Head may hit pillar of car • Injuries are typically worse on left side of body • Head may pop out of window and pop back into vehicle • Head may hit objects before re-entering vehicle
MOTOR VEHICLE ACCIDENTS • Rollovers • Generally less lethal than head-on and side impact collisions • If not wearing seatbelt may be thrown around like a rag doll in compartment • Receive multiple injuries • Body may also pop out of vehicle and pop back in again • Check for paint on head or hair on vehicle
MOTOR VEHICLE ACCIDENTS • Rollovers • Most rollovers occur because driver runs off the road and attempts to steer back onto road • Vehicle skids sideways • Vehicle tips towards leading side • Where rollover begins is where tire marks stop • Center of gravity determines extent of rollover • SUV’s rollover more
MOTOR VEHICLE ACCIDENTS • Rollovers • Vehicles that roll over go airborne • Cars land on edge of roof opposite side that led in rollover • SUV’s impact on leading edge of vehicle roof then onto tires • Most vehicles only roll over once
MOTOR VEHICLE ACCIDENTS • Rear Impact Crashes • Least common of fatal accidents • Mainly see whiplash syndrome • May have fire due to faulty gas tank • May have seatback failure
MOTOR VEHICLE ACCIDENTS • Seat belts • Lap belts • Shoulder belts • Three-point belts • Lap plus shoulder
MOTOR VEHICLE ACCIDENTS • Seat belts • All new vehicles have three-point belts • Since 1997, 69% decrease in MVA fatalities due to seat belt law • Jack-knifing may occur with lap belts • Seat belt syndrome
MOTOR VEHICLE ACCIDENTS • Air bags • Significantly less effective than seat belts • Only improves your chance of survival by a maximum of 5% • May produce injuries especially in children and small adults • Less than 10 inches from bag
MOTOR VEHICLE ACCIDENTS • Motorcycle Accidents • Fatalities are due mostly to head or neck injuries • Many abrasions • High speed crashes wearing helmets are only to keep brain matter from spreading over the freeway
MOTOR VEHICLE ACCIDENTS • Motorcycles • Most fatalities are due to • Car drivers don’t see the motorcycle • Environmental factors • Wires or cables stretched across roadway • Avulsed limbs • Decapitation
MOTOR VEHICLE ACCIDENTS • Suicide by Motor Vehicle • Usually head on into a fixed object • Check soles of shoes of driver for pedal marks • May also do this to determine who was driving in a crash
MOTOR VEHICLE ACCIDENTS • Toxicology and MVA’s • A complete toxicological screen should be done • Include Carbon Monoxide levels • In 1999, 38% of traffic fatalities were alcohol related down from 49% in 1989 • Should also drug test passenger • Passenger often turns out to be driver • Blood may be kept at a hospital for up to 7 days
MOTOR VEHICLE ACCIDENTS • Pedestrian Deaths by MVA’s due to four factors • Speed of vehicle • Physical characteristics • Braking of vehicle • Whether victim was a child or an adult
MOTOR VEHICLE ACCIDENTS • Pedestrian Death – Speed of Vehicle • Fracture of spine, 45 km/h • Rupture of thoracic aorta, 85 km/h • Inguinal skin rupture, 95 km/h • Dismemberment, above 95 km/h
MOTOR VEHICLE ACCIDENTS • SUV’s • Child Pedestrians • Body’s center of gravity is below bumper • For non-braking or late braking vehicle: Victim will be impacted, slammed down and run over • For braking vehicle: Front of vehicle dips below child’s center of gravity and child may be thrown forward
MOTOR VEHICLE ACCIDENTS • Adult Pedestrians • Body’s center of gravity is above bumper, except for tall vehicles, i.e. pick-up or SUV • Trucks or SUV’s • Non-braking: Victim is slammed down and run-over • Braking: Victim is thrown forward
MOTOR VEHICLE ACCIDENTS • Adult Pedestrians • Automobiles or light trucks • Non-braking or late braking at high speeds: Victim is picked up and thrown over top of car • Look for scuff marks or dents on bumper, hood, roof and possible trunk of vehicle • Non-braking at moderate speeds: Victim will be picked up, land on the hood and slide backward impacting windshield, then slide off (usually sideways) • Look for scuff marks or dents on bumper, indent on hood and impact to windshield • Glass may be in hair of victim • May find hair or clothing in cracks in paint or in glass on vehicle
MOTOR VEHICLE ACCIDENTS • Automobile or Light trucks • Braking at high speeds: Victim may be thrown forward or may be picked up and land on the hood and then propelled forward again • Look at knees and calf region for fractures • “Bumper Fractures” • If walking or standing sideways may be fractures at different levels or fracture in only one leg
MOTOR VEHICLE ACCIDENTS • Automobile or light truck • Individuals picked up and thrown by a vehicle may be stripped of clothing • If Victim is run over by a wheel • Look for tire marks and abrasions on opposite side of body
MOTOR VEHICLE ACCIDENTS • Future of MVA’s • Black Boxes • Already in Mercedes and • All GMAC models