Blood Stain Analysis Notes - PowerPoint PPT Presentation

1 / 12
About This Presentation
Title:

Blood Stain Analysis Notes

Description:

Another forensic method is the analysis of blood stains left at a crime scene. Blood stain analysis can be very revealing about the method of injury, and the ... – PowerPoint PPT presentation

Number of Views:91
Avg rating:3.0/5.0
Slides: 13
Provided by: jason133
Category:

less

Transcript and Presenter's Notes

Title: Blood Stain Analysis Notes


1
Blood Stain Analysis Notes
  • Another forensic method is the analysis of blood
    stains left at a crime scene.
  • Blood stain analysis can be very revealing about
    the method of injury, and the positions of the
    people involved in a bloody crime scene.

2
Blood Stain Analysis
  • By using blood stain analysis investigators can
    determine the positions of the people involved.
  • The physics of blood falling a distance relates
    to the pattern of the blood stain.

3
Velocity of Object Causing Blood Loss
  • Low velocity generally larger diameter drops.
  • Medium velocity medium diameter stains, blunt
    force, stabbing,etc.
  • High velocity small diameter of stains, bullets,
    explosions, etc.

4
Passive Blood Stain
  • Passive blood stains are reflective of blood
    dropping vertically to the surface.
  • This diameter of the stain is used to analyze the
    height of the fall of blood.

5
Transfer Blood Stain
  • Transfer stains reflect friction between objects
    and less defined blood drops.
  • Transfer stains sustain the contact between
    objects.

6
Projected Blood Stain
  • Projected blood stains will have eliptical shapes
    due to air resistance, and contact with the
    surface.
  • The size of the projected stains can relate the
    velocity of the object causing the blood stain.

7
Blood Stains
  • What can be inferred about the stain to the right?

8
Blood Stains- Directionality
  • The shape of the stain can be used to determine
    the direction of travel, and hence the point and
    position of impact.

9
Directionality
10
Impact Angle Determination
  • The angle of impact can be determined by the
    length and width of the blood droplet.
  • The surface tension of the object the blood is on
    needs to be calculated as well.
  • This angle is then traced backwards to possible
    points of origin.

11
Point of Origin
12
Point of Origin
  • Strings or lasers can be used to backtrack blood
    droplets to find the point of origin.
Write a Comment
User Comments (0)
About PowerShow.com