forensic toxicology
DESCRIPTION
Forensic Toxicology. 11.20.08. Deaths Investigated by Forensic Toxicologists. Accidental Poisonings Drug Abuse Cases Suicidal Poisonings Homicidal Poisonings. Main Questions Addressed by Forensic Toxicologist. Is a drug or poison present? If so, what is the substance? - PowerPoint PPT PresentationTRANSCRIPT
Deaths Investigated by Forensic
Toxicologists
Deaths Investigated by Forensic
Toxicologists Accidental Poisonings Drug Abuse Cases Suicidal Poisonings Homicidal Poisonings
Main Questions Addressed by
Forensic Toxicologist
Main Questions Addressed by
Forensic Toxicologist Is a drug or poison
present? If so, what is the substance?
How much of the substance is present? Is the concentration great enough to cause or contribute to death?
How was the drug/poison administered?
Properties of Ideal Poison
Properties of Ideal Poison
Undetectable by senses Soluble in water Delayed effect Easily obtained Non-traceable Symptoms mimic actual disease Undetectable by scientific instruments
Potent
Potencies of Various Poisons
Potencies of Various Poisons
Agent Botulinum toxin
Ricin Strychnine Sodium arsenite
Sodium cyanide
Thallium
Lethal Dose 0.05 mg 0.5 mg 100 mg 200 mg 250 mg 1000 mg
General Classes of Poisons
General Classes of Poisons
Gases – HCN, CO Metallic Poisons – As, Sb, Pb, Li, Hg, Tl
Non-volatile organics Corrosive poisons – strong acids/bases
Salts – NaCN Alkaloids Pesticides
Carbon Monoxide (CO)
Carbon Monoxide (CO)
Normal level of 1-3% in body (up to 10% in smokers)
Fatal level at autopsy considered to be >50% for a healthy middle-aged male
CO prevents Oxygen binding to hemoglobin (red blood cells) Leads to suffocation CO victims have “cherry pink color”
Metal PoisonsMetal Poisons
Most common – As2O3 (arsenic) Death within 24 hours Can be given in trace amounts over long periods of time
Symptoms: Vomiting Diarrhea
AlkaloidsAlkaloids
Nitrogen-containing organic base
Found in Plants and fungi
Strychnine most common Death from muscle over-contraction, leading to respiratory system failure
Spasms and convulsions
PesticidesPesticides
Many (most?) of the pesticides we spray on our lawns, gardens, etc. are poisonous
Growing in popularity Easy to obtain Common enough that it won’t raise suspicions as quickly if traces found
Toxicological Analysis of Tissues
Toxicological Analysis of Tissues
A. Collect sample of all body fluids
B. Collect samples from organs and tissues
C. Begin analysis as quickly as possible after death due to quick metabolism of toxins
D. Look for traces of poison OR their metabolic product (what toxin is changed into when broken down)
Samples Collected at Autopsy
Samples Collected at Autopsy
Fluids Blood – up to 100mL
Urine – 100 mL
Bile – all available
Vitreous – all available
Gastric contents – 50g
Soft Tissue Liver – 100g Brain – 100-200g
Kidney – 50g Lung – 50g Spleen – 50g
Intentional Poisoning Trends
Intentional Poisoning Trends
Perpetrator Profile Caucasian Male Average or above IQ
Underachiever Personality defect Non-confrontational
Non-athletic Neat, orderly, meticulous
Loner
Gender Male – 46% Female – 39% Unknown – 16%
Top 5 Homicidal Poisons
Top 5 Homicidal Poisons
Arsenic – 31% Cyanide – 9% Strychnine – 6% Morphine – 3% Chloroform – 3%
Possible SymptomsPossible Symptoms
Constricted/dilated pupils (opioids, organic phosphates)
Breath odor (arsenic – smells of garlic)
Hair loss (Thallium) Convulsions (strychnine) Paralysis (botulism) Coma (depressants, hypnotics) Skin color (CO=red, nitrites=blue) Skin appearance
(arsenic – hyperkeratosis, warts) (dioxin – chloracne)