forensic test one (role of pathologists)

•Law enforcement

•Specialized crime scene personnel

•Coroner &/or medical examiner

•Crime lab personnel

•Prosecuting attorney

•Specialists/expert witnesses

Death investigation requires many different people

no longer just ‘permanent cessation of cardiac &/or respiratory function’

Definition of death can be problematic

•determination of when to pronounce death can be controversial

•harvesting organs, moving brain dead individuals, etc.

Concept of ‘brain death’

• early changes

• late changes

• postmortem

changes of death

Medical examiners

•Most general pathology training includes limited or no exposure to forensic pathology

external exam

•Photograph

•Retrieval of evidence

•Description & removal of clothing &/or medical devices

•Cleansing & rephotograph

•General description of body

    (race, hgt, wgt, sex, birthmarks, scars, etc,)

•Injuries &/or abnormalities

internal exam

•‘Y’-shaped thoracoabdominal & intermastoid incisions

•Toxicological samples & organs removed

•Evidence recovery (bullets, drugs, etc.)

•Photographs & diagrams drawn

additional studies

•Histology (microscopic tissue exam)

•Toxicology

•Fixation of heart & brain in formaldehyde

•Review medical records, etc.

•Assign cause & manner of death, prepare autopsy report

Time of death (‘when’):

•Can’t pinpoint time of death, but may establish an interval

•Can’t determine @ crime scene, is a complex process

•General investigation & scene investigation important

•Last scene alive, food, mail, etc.

•Rigor, livor, & algor mortis, & decomposition

•Rigor mortis: PM stiffening of muscles & joints

•Timeline for onset & relaxation subject to variables

•Graded as: absent (limp), minimal (some stiffness), moderate (stiffer but breakable), full (complete stiffening)

•Lividity (livor mortis): discoloration on ‘dependant’ areas

•Color varies, but normally reddish-purple

•Discoloration does not disappear & timeline subject to variables

•Graded as: absent, faint, full, fixed/unfixed

•Body cooling (algor mortis): 1.5-2 degrees/hr PM

•Use lab thermometer or electronic meter for core temp (rectum, liver)

•Timeline subject to variables:

•ambient temperature, humidity, & air currents; location (air, water, ground); body mass & clothing; time elapsed

•Decomposition: observable changes on external surface

•~ 24 hrs, green discoloration of lower abdomen (caecum)

•~48 hrs, entire abdomen w/ green discoloration

•~72 hrs, torso green

Correlation of body & its environment (‘where’):‘

•May or may not be possible

Identification (‘who’):

•Visual, fingerprints, dental, medical, circumstantial, anthropological, DNA

Cause of death (‘what’):

•Injury or disease process that initiates chain of events sufficient to result in death

•Natural causes: heart attack, lung cancer

•Medicolegal causes of death: gunshot or stab wounds, asphyxia by hanging, blunt force trauma

Manner of death (‘how’):

•Medical classification of a death according to circumstances surrounding the death

•Standard of certainty= ‘reasonable medical certainty’