Forensics

• Epithelial tissue

  
• Muscle tissue

  
• Nervous tissue

  
• Kidney tissue

  
• Liver tissue

  
• Cartilage tissue

  
• Adipose tissue

  
• Compact bone

  
• Blood cells

  
• Absorption: How a toxin enters the bloodstream

  Distribution: How a toxin transfers from one location to another

  Metabolism: How a toxin is broken down in the liver, releasing byproducts

  Excretion: How a toxin is eliminated from the body
• Active decay: Greatest loss of mass during decomposition

  Advanced decay: Period after most soft tissue has decomposed
• Autolysis: Buildup of carbon dioxide increases cell acidity, breaking down the cell membrane and thereby disintegrating the lysosome; cells begin to be destroyed by their own digestive enzymes
• Bloat: Intestinal bacteria entering a decomposing body, producing gases that cause it to inflate
• Carbon monoxide: Gas; found in car exhaust, gas stoves; causes red patches on the chest, respiratory distress, and reduced oxygen in the blood
• A human is born with 450 cartilaginous bones which fuse to form 206 hardened ones. As this happens, lines from in the bone. This is known as ossification, and is carried out by osteoblasts.
• Connective tissues: Cartilage, adipose (fat cells), bone cells, blood

  Support, protect, and give structure to other tissues and organs

  Observing the amount in a body may help determine the age or habits of a person, the time of death, and how long the body has been dead
• Depressant: Alcohol, Xanax, Ativan; reduce messages through the central nervous system; induce sleep, relieve anxiety, prevent seizures, slur speech, blur vision, and cause loss of coordination
• Dosage: Amount of toxin absorbed

  Potency: Concentration of toxin

  Duration: Acute or chronic

  Exposure method: Injected, inhaled, ingested, or absorbed through the skin
• In cooler temperatures with a lack of moisture, instead of decaying, the body mummifies.

  In warmer temperatures with a surplus of moisture, the body decomposes much faster than normal.

  When buried, the body begins the process of saponification; the bacteria in the soil interacts with the oils and fats of the corpse.
• Endothermic: Process accompanied by or requiring the absorption of heat

  Exothermic: Process accompanied by or requiring the release of heat
• Epithelial tissue: Forms the covering of internal and external surfaces, organs, and cavities; protects the body and regulates secretion and absorption

  Appears elongated with a bumpy texture

  Skin, for one, changes color and texture after death in predictable ways, which allow the time of death to be estimated
• Development of the femur:

  (Condyle: Round knob that articulates with another bone; Trochanter: Two massive process unique to the femur, attachment site for muscles)

  Great trochanter appears at about 4 years.

  Lesser trochanter appears at 13-14.

  Femur head fuses to shaft at 16-18.

  Condyles join shaft at about 20.
• The organs which are commonly examined because they filter the body's blood are the kidney and the liver.
• 2 hours to 2 days: Three mortises; autolysis; skin appears marbled

  3 to 5 days: Skin blisters; abdomen swells

  8 to 10 days: Corpse bloats and collapses; fluids begin to leak; eyeballs and most other tissues liquefy; skin sloughs off

  2 weeks to 2 months: Almost all tissues dried; teeth and nails fall out; body chemically interacts with surrounding soils

  2 months or more: Mostly bone and a small amount of tissue remains; bones start to decompose
• Algor mortis: After one hour, the body begins to cool to ambient temperature at a rate of about 1 degree Fahrenheit per hour

  Livor mortis: Begins after 20 minutes and fades after 12 hours; lividity which causes bluish-purple discoloration

  Rigor mortis: Muscles become rigid within 2 hours of death, and soften again after about 48 hours
• Suture marks: Zig-zag lines atop the skull

  Coronal (frontal) suture marks close around age 50

  Sagittal (middle) suture marks begin to close between 30 and 40

  Lambdoid (hindmost) suture marks begin closing around 21, and fully close around 30
• Scott Test

  Reagents: Cobalt thiocyanate in glycerine and water; concentrated hydrochloric acid and chloroform

  Toxin detected: Cocaine

  Outcome: Blue color in chloroform layer
• Qualitative test: Indicates the presence of a drug

  Quantitative test: Indicates the amount of a drug
• Presumptive test: Done quickly, possibly on-field, to determine the drug present

  Confirmatory test: Done in a lab to identify all possible drugs and metabolites
• Ossification: Process of bone formation; begins in the 3rd month of development and is complete in late adolescence. As bones age, the ossified bone becomes porous
• Nervous tissue: Makes up the brain, spinal cord, and nerves

  Appears with spider-like appendages

  Used in determining the cause of death
• Muscle tissue: Helps move the limbs, and moves substances around the body

  Skeletal (attached to bones), smooth (makes up blood vessels and organs), cardiac (makes up the heart muscle)

  Appears long and stretched, stacked in horizontal lines
• Mass spectrometry: Measures the mass-to-charge ratio of molecules present in a sample; can be used to calculate the exact molecular weight of various components
• Marsh test

  Reagents: Zinc and sulfuric acid

  Toxin detected: Arsenic

  Outcome: Yellow precipitate
• Marquis test

  Reagents: Formaldehyde and sulfuric acid

  Toxins detected: Ecstasy, speed, fentanyl

  Outcome: Blue for ecstasy or speed; orange for fentanyl
• Manner of death: Natural, accidental, suicidal, or homicidal

  Cause of death: Event occasioning death

  Mechanism of death: Physiological cause of death
• Liver tissue: Made up of specialized cells, hepatocytes, which work to break down ingested chemicals

  Appears fuzzy, with open spaces where blood vessels would be
• Kidney tissue: Networks of glomerulus (clusters of nerve endings, spores, or small blood vessels) where waste products are filtered from the blood found around blood vessels, appearing as open, blank circles
• Infrared spectroscopy: Measures the interaction of infrared radiation with matter in the sample
• Humerus

  At infancy, the head is unfused

  The head fuses from 4 to 6 years

  The bone fuses to the shaft at 18 to 20 years