Honors Forensic Science

I. Forensic Pathology  A. Pathology = branch of medicine associated with the study of structural changes caused by disease or injury  B. Pathologist = medical doctor who specializes in determining how disease affects the body  C. Forensic just adds the legal aspect to field

II. Coroner vs. Medical Examiner  A. Coroner  i. Usually elected official  Ii. Does not have to be a doctor

b. Medical Examiner  i. Often have both law enforcement and quasi-judicial powers  Ii. Operate out of centralized offices  Iii. Usually attends crime scenes

 Iv. Duties  1. find evidence  2. preserve evidence  3. report accurately  4. also decides who gets autopsied  A. Traumatic  B. Unusual  C. Sudden  D. unexpected

II. Autopsy  A. Purpose – observe and make a permanent legal record as soon as possible of the gross and minute anatomical peculiarities of recently deceased body

b. Goals  i. Determine identity of decedent  Ii. Determine cause of death – direct agent that leads to death (ex. Bullet, poison)  Iii. Determine manner of death  1. Accident  2. Suicide  3. Murder  4. natural

 Iv. Determine mechanism/mode of death – what happened to body as a result of its run- in with the cause (ex. Bullet tears hole in aorta and blood fills chest cavity)  V. Determine time of death

 C. ME/Pathologist protocol in approaching body for autopsy  i. Visual inspection  Ii. Injury inspection  Iii. Internal exam  Iv. Presentation to other experts  V. Reconciliation of exhibits  Vi. Presentation of findings (autopsy reports)

d. Visual Inspection  i. Prior to this blood sample taken, x-rays, weight and measurements are done  Ii. Begins with clothed or nude body depending on circumstances at time of death  Iii. Body is photographed with attention to unusual details

 Iv. Trace evidence is collected  V. Clothing is removed and each piece is air- dried and packaged separately for processing with descriptions  Vi. Head hair combed  Vii. Rape kit may be done

 Viii. Body openings examined  Ix. Hands (should have been bagged at scene) examined – ex. Damaged nails, nail scrapings, GSR  X. Fingerprint/footprint cards  Xi. Entomological samples collected

 Xii. Notes of injuries and photos  Xiii. Overall conditions of body noted  Xiv. May use special lights to see bruises etc.  Xv. Body mark documentation – tattoos, scars

e. Injury Inspection – commonly seen injuries and causes of death  i. Asphyxia  1. insufficient amounts of oxygen reach the brain or other organs

2. Natural causes  A. Disease that cause the respiratory system to shut down  i. Ex. Emphysema  Ii. Pneumonia  Iii. Flu  Iv. Asthma  V. Larynx disorders

3. Criminal means of asphyxia  A. Strangulation  i. Homicide – manually or by ligature – marks on neck are more horizontal than in suicide  Ii. Suicide – generally see marks on neck that curve upwards  Iii. Accidental - rare

 Iv. Characterized by  1. intensive heart congestion – enlarged heart  2. venous engorgement  3. cyanosis – blue discoloration of lips and fingertips

b. drowning  i. Results from inhalation of water which causes choking and rapid formation of mucus in throat and windpipe  Ii. Mucus inhibits respiration

 Iii. Characterized by  1. foam cone covering mouth and nose  2. fluids in lungs

iv. 5 stages of drowning  1. surprise – person is stunned and inhales water  2. holding breath – person tries to hold breath while struggling  3. pink foam – person inhales deeply and pink foam is expelled  4. respiratory arrest – thoracic movement and pupils dilate  5. final struggle – 3-4 quick attempts to breathe and find air

c. Smothering  i. Occurs when airways are closed by obstructing object  Ii. If soft object – usually no visible sign of trauma expect for small lacerations on lips  Iii. Cyanosis may or may not be present  Iv. Petechial hemorrhage – pin-point blotches or red spots on face, typically around eyes

ii. Wounds –can often reconstruct what happened from types of wounds  1. Penetrating  A. Bullet wounds  i. follow principles of physics  Ii. Velocity is most important factor, not size of bullet  Iii. fragmenting ammunition designed to spread out and hit vital organs

 Iv. High powered rifles more deadly than handguns or shotguns  V. Entry and exit wounds are important  Vi. Entry wound generally smaller than exit  Vii. Often able to identify caliber of weapon from entry wound

 Viii. Often see powder burns  1. held at distance – no other surface information than wound  2. held on skin – “rim burns”  3. held a few inches away – soot on wound but no burn – hair may be scorched  4. held a few inches to a few feet away – “stippling”

b. Stab Wounds  i. Slash wounds  1. look like bullet wounds that graze the skin  2. hesitation marks – often seen in suicide cases  3. typically rectangular in shape

 Ii. Incision wounds  1. lengths greater than depth  2. greater amount of sub-surface tissue exposed in almost oval fashion

 Iii. Puncture Wounds  1. almost no geometric shape, except perhaps circular  2. most distinguishable from clean –cut edges

 Iv. Pre-mortem wounds gape and bleed profusely  V. Post – mortem wounds do not bleed profusely  Vi. If attacker stuck victim and twisted object, more damage is caused and death more likely

2. Non-penetrating  A. Results from clubbing, kicking, or hitting victims  B. Has a crushing effect on body resulting in contusions, abrasions, lacerations, fractures, or rupture of vital organs  C. Red-blue contusions (bruises) almost always present

 D. Brain contusions  i. Difficult to analyze  Ii. Trauma most severe on opposite side of impact

 E. Wounds to body area take longer to cause death  i. Due to process of subdural hematoma (blood clot) that travels to brain

iii. Miscellaneous  1. Rape Wounds  A. Examination of genital area for signs of tearing, scratching, or bruising  B. Existence of venereal disease and/or pregnancy  C. Foreign pubic hair, blood stains, seminal stains collected  D. Sometimes able to collect DNA

2. Poisioning/Drugs  A. Usually determinable by looking at discolorations of body  i. Cherry-red lividity is sign of carbon monoxide  Ii. Other toxins give off unusual odors  Iii,. Needlemarks between fingers and/or toes suggest drug use  Iv. Diagnosis requires toxicological confirmation

3. Burn Wounds  A. Caused by heat, a chemical or electricity  B. Often found in “pugilistic” position with clenched fist  C. Heat generally causes the protein in body to contract  D. Electrical burns – occur in pairs; one from point of contact, other from grounding point where current passes out of body

4. Traffic Fatalities  A. Analyzed to determine if victim was driver, passenger or pedestrian  B. Motorcycle injuries more severe  C. Automobile drivers often have circular impression in chest area  D. Passengers normally have extensive knee and spinal injuries

 E. Pedestrian injuries  i. Extensive lower body injuries – “bumper fractures”  Ii. The lower on the leg the “bumper fracture”, the more likely it is the driver attempted to slow down  Iii. Run-over injuries are distinguishable by amount of compression tissue damage

f. Internal Exam  i. “Y” incision  Ii. Organs removed and examined for injury and disease and then weighed  Iii. Stomach contents examined – may help determine time of death and tie victim to certain places  Iv. Blood for toxicological screens

 V. Bladder – fluid removed for drug analysis  Vi. Reproductive organs tested for pregnancy  Vii. Generally, organs are replaced unless something is amiss

 Viii. Head  1. eyes/eyelids – sample vitreous fluids  2. hemorrhages may indicate hanging or strangulation  3. cut off face to examine skull  4. skull opened and brain examined

IV. Special case autopsy  A. Fetal Death  i. A fetus of less than 500 g is “miscarried” – expelled from mother’s body through natural or traumatic means  1. no autopsy is done and no death certificate is issued

 Ii. A fetus of more than 500 g is born dead – a still birth  1. in absence of violence or suspicion, a special fetal death certificate is issued with cause of death “non-viability” of fetus

 Iii. A fetus of more than 500 g is born alive and then dies  1. standard death certificate  2. autopsy usually done

b. exhumations  i. Order to exhume body must be obtained from the court  2. problems – embalmed bodies have had blood drained and replaced with formaldehyde compounds; remains may have skeletonized

c. Partial bodies/amputations  i. Difficult to establish cause of death if entire body is not present

V. Autopsy Reports  A. Pathological diagnosis  B. Cause of death  C. Contributing cause of death – usually a pre-existing illness or condition  1. ex. Pneumonia or asthma

 D. Mechanism of death  i. Usually anything expressible only in medical jargon  Ii. Ex. Lung sacs became obstructed and could no longer transport oxygen

 E. Immediate cause of death  i. Usually gets at cause of death  Ii. Expressed in medical jargon or in laymans terms  Iii. Ex. Asphyxia or wound

 F. Manner of death –  Usually is mechanism plus immediate cause; suicide, homicide, accidental, natural or unknown