Bodily fluids in forensics

Bodily fluids

• Blood

• Saliva

• Semen

• Urine

• Feces

• Vitreous humor

Saliva

• slight alkaline secretion

• Consists of

  • Amylase

  • Lysozume

  • Salts

  • Mucin

Saliva as a forensic indicator

• Found usually in spit, bite marks and masks or face coverings

• DNA

• Tox

• Usually taken from living individuals due to it being non invasive

Ultraviolet fluoreces

• lights up blood spatter on a scene but damages the DNA

Phadebas paper test

• Amylase diffuses blue

Rapid stain identification of Human Saliva

• Fastest and cheapest test

• Amylase- antibodies

• False positives can be from urine or breast milk

Semen

Contains

• Sperm
  Fructose

• Citric acid

• Calcium

• Various proteins

Semen as a forensic indicator and presencces

• typically used in sexual assault cases

• DNA is stable in dried stains

• must detect presences of spermatozoa

Urine

• pH 6.2

• Women have more DNA

• consists of

  • Urea

  • Salts

  • Organic ammonium salts

  • Organic compounds

  • Limited bacteria

Urine as a forensic indicator

• Drug use or poisioning

• Massive postmortem redistribution of urine

Feces as an indicator

• Brown there is a breakdown of hemoglobin

• Yellow indicates bile

• Green indicates biliverdin

Forensic scat

• Identification with cells of digestive track

• Links to locations thru diet

  • MIneral indicator

  • Cellous/fiber, indicator of health

  • Microbes, indication of health and diet

• Poisoning

Vitreous Humor

• Gel consistency behind cornea

• Encased and protected

• Does not replace itself

• Decays slowly

• contains

  • No bacteria

  • drugs pass through

  • Electrolytes

  • Phagocytes (trash cans)

Vitreous humor as a forensic indicator

• Postmortem interval

  • Decays slowly

• Toxicology

  • Enclosed