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A Qualitative Theory for Crime Scene Analysis - Coggle Diagram
A Qualitative Theory for Crime Scene Analysis
Crime Scene Analysis
a forensic discipline that seeks to identify as many objective statements as possible regarding what happened and it what order it happened and in what order it happened during a given phenomenon
accomplished by identifying, through an examination of the evidence and the context in which it is found, specific actions that occurred
Heinrich and Benner
given a series of actions associated to a specific incident, any given action has a unique causal and temporal relationship with every other associated action
an incident is the phenomena being investigated; each incident is made up of a series of associated actions
an action is a change in state of some particular actor (that actor may be either an animate or inanimate object)
an object is a physical object, not a point particle; it has mass and is three-dimensional, thus we can exclude quantum considerations
Axioms 1-6
axiom 1: every object is unique
an object is consistent with itself, and it remains consistent with itself until converted into something else
example: a complete cartridge, through firing, becomes the bullet or perhaps bullet fragments that were originally present in that cartridge, the powder expelled is still the propellant that was present in that cartridge, and the expended cartridge case remaining is still the cartridge case that was present in that unique complete cartridge
axiom 2: while it exists, an object must exist continuously in both time and space
every modern physical theory an object was understood to have three spatial dimensions that could be referenced to a given manifold
example: describe an object in a crime scene in relation to some Cartesian coordinate system
during any object's existence we can reduce the interval between any two points in the time vector to as small a value as we desire, but that interval will still have a value
axiom 3: every point of an object's existence is connected to some other point of its existence
from the time of an object's creation to its conversion into something else, it traces a continuous path through space-time, existing in all four dimensions at all time of its existence
axiom 4: for any temporal value of a world line that follows some other value of the object's world-line, that temporal value must be greater
although a continuing philosophical question, movement through space-time appears to be a one-way trip
axiom 5: every value of an object's world-line is unique
an object is itself unique, and as it is three-dimensional, the object must exist at some specific point in time and space throughout its existence
an object at rest in space will remain in some particular spatial dimension within the manifold
axiom 6: to create an action (to produce some change in state of an object) there must be a cause
a physics event is merely an instantaneous moment in the object's history; an action as described here, represents an object undergoing some change in state
example: if the action were "bullet fired," in effect this would consist of a series of physics events (the near instantaneous moments) of the trigger being pulled on the weapon, the powder igniting in the cartridge case, the pressure building in the cartridge case, and the bullet being propelled down the barrel by the pressure
Axiom 7-12
axiom 7: effect cannot precede cause
changes in state cannot occur until the introduction of a change agent
a basic principle of CSR is pursuing causal connection; what exactly is interacting to cause an change in state
axiom 8: an action (a change in state of an object) can only occur as a function of some interaction
Newton's laws of motion tell us that to accelerate any object in any manner (thus cause a change in state) there must be some force
without the presence of a fore, the object simply would not change
example: blood would remain in the body, fingerprints would not be deposited, objects would not be displaced
the nature of the force acting on the object may be an interaction with another object, where world-lines intersect in space-time
example: a bullet striking a surface causing a ricochet in the first and creating a defect in the second
axiom 9: in order to interact, the spatial and temporal existence of objects must overlap in some way - or - the object must exist spatially and temporally within the influence of a fundamental force
if the change in state of an object occurs as a result of an interaction with another object, the two objects must come in contact with one another; this demands that their world-lines (their spatial and temporal positions within the manifold) converge at some point
axiom 10: every action has at least one prior action that influenced it
while an object exists, it exists somewhere, and that existence is continuous throughout the life of the object; no object simply appears
in crime scenes there are no primordial actions; some set of conditions/action leads to every other action
axiom 11: any two actions associated to a given incident have a unique causal relationship
causal connection is one of the most basic principles in crime scene reconstruction, but it can be one of the more difficult ideas to recognize
the value of recognizing direct causal dependence is that it allows the analyst to link and order certain actions
axiom 12: any given set of actions will have a unique temporal relationship
whereas causal connection between associated actions is more convoluted in explanation and recognition, temporal relationship is an unmistakable idea
temporal relationship manifests itself in two way in CSR
may be exact
absolute chronology
may be more ambiguous
relative chronology