Credibility problem
This presentation is the property of its rightful owner.
Sponsored Links
1 / 25

Credibility Problem PowerPoint PPT Presentation


  • 90 Views
  • Uploaded on
  • Presentation posted in: General

Credibility Problem. Are we Analysts or Investigators? Do we Understanding our job?. Definitions. Criminalistics Principles Individuality Divisible Matter Transfer. Principle of Individuality. No two objects in nature are identical. Principle of Divisible Matter.

Download Presentation

Credibility Problem

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Credibility problem

Credibility Problem

Are we Analysts or Investigators?

Do we Understanding our job?


Definitions

Definitions

  • Criminalistics Principles

    • Individuality

    • Divisible Matter

    • Transfer


Principle of individuality

Principle of Individuality

No two objects in nature are identical.


Principle of divisible matter

Principle of Divisible Matter

Matter divides into smaller components

when sufficient force is applied.


Principle of divisible matter1

Principle of Divisible Matter

Corollaries:

  • The process of division may produce features that are unique to the two pieces.

  • When an object is separated into pieces, some features of the one piece will be retained by the separated piece.

  • The passage of time may affect the two pieces differently


Principle of transfer

Principle of Transfer

When two objects come into contact, matter will be transferred from one object to the other, and from the other to the one


Principle of transfer1

Principle of Transfer

Corollaries:

  • When contact occurs between two objects, the transfer may be in either, or both, directions

  • The rate and quantity of transfer depends on the properties of the materials in contact, the forces involved in the contact, and the time of such contact.

  • The persistence of transferred matter depends on the properties of the transferred matter, the properties of the recipient object, and post-transfer actions affecting the recipient and transferred objects.


Unit operations

Unit Operations

Recognition

Preservation

Identification

Individualization

Reconstruction


Unit operations1

Unit Operations

Recognition

Understanding and locating matter that may inform us about the circumstances of an event


Unit operations2

Unit Operations

Recognition

Preservation

Observation, documentation, and collection to maintain the information value of physical evidence


Unit operations3

Unit Operations

Recognition

Preservation

Identification

Place object in a class of similar objects


Unit operations4

Unit Operations

Recognition

Preservation

Identification

Individualization

Establish that two things have a common origin


Unit operations5

Unit Operations

Recognition

Preservation

Identification

Individualization

Reconstruction

Determination of time sequence of events during incident


Problems

Problems

  • Technical errors


Cognitive errors

Cognitive Errors

  • Examples

    Efficiency Fallacy

    Genetic Fallacy

    Fallacy of expectation


Efficiency fallacy

Efficiency Fallacy

Reliance on easily observable facts


Genetic fallacy

Genetic fallacy

Validity based on the origin of the data


Fallacy of expectation

Fallacy of expectation

Result is anticipated based

on understood paradigm


Hypothesis formulation

Hypothesis Formulation

  • Deduction

    • The Rule: We have a jar of blue marbles.

    • The Case: We select a marble from the jar.

    • The Result, our hypothesis: The marble will be blue.


Hypothesis formulation1

Hypothesis Formulation

  • Induction

    • The Case: We have a marble from this jar.

    • The Result: This marble is blue.

    • The Rule, our hypothesis: The jar contains blue marbles.


Hypothesis formulation2

Hypothesis Formulation

  • Abduction

    • The Rule – This is a jar with blue marbles.

    • The Result – This is a blue marble

    • The Case, our hypothesis – This marble came from this jar.


Alternative hypotheses

Alternative hypotheses

  • Difficulties

    • Linear thinking

Failing to think outside of the box


Alternative hypotheses1

Alternative hypotheses

  • Difficulties

    • Linear thinking

    • Ockham’s razor

The simplest explanation is the best


Alternative hypotheses2

Alternative hypotheses

  • Difficulties

    • Linear thinking

    • Ockham’s razor

    • Modal fallacy

Confusion of terms, e.g., “Could be” and “is”


Alternative hypotheses3

Alternative hypotheses

  • Difficulties

    • Linear thinking

    • Ockham’s razor

    • Modal fallacy

  • Evaluation

    • Mathematical/statistical approach

    • Alternative reconstruction


  • Login