The Original Software* for the Directional Analysis(c) of Bloodstain Patterns Found at Crime Scenes
(The only BP Analysis program created by a Physicist and based solidly on the laws of physics.)
The BackTrack program's objective is to provide the crime scene investigator with a scientific tool.
"Directional Analysis" finds the locations of the blood sources by working backwards from the bloodstain patterns.
"Directional Analysis" was invented and copyrighted by the author in the year 2002.
The victim's horizontal position is found to within +/- 2 centimeters and also was the victim was standing or lying down.
Only measured quantities from the crime scene are utilized along with the known laws of motion.
Computers allow the investigator sto make use of their unique ability to analyze and display information in 3D space.
However, I firmly believe that the investigator's judgment and skill should always take precedence.
It is well known that "clever" computer algorithms can automatically fit ellipses to the shapes of bloodstains.
By deliberately avoiding this shortcut, one can take advantage of the superior judgment of investigators.
I have seen people who should know better, rely on computers over common sense.
Consult the list of papers published in refereed journals for further information about this technique.
ALC, Ottawa, December 1 2010
This site contains ...
Free trial versions of BackTrack/Win and BackTrack/Images.
Screen shots of a BackTrack analysis and the 3D presentation with Crime Zone.
Directional Analysis(c) explained.
List of clients.
Handbook for BP analysts.
Training courses available.
* The use of computers and digital images for blood spatter analysis by Directional Analysis(c) with the fitting of ellipses to the shapes of the bloodstains are unique procedures that were first invented and developed in 1992, by A L Carter Ph D. The software is distributed by Forensic Computing of Ottawa Inc.
NEW (Dec 1 2010): BackTrack Suite Version 4.52 for XP, Vista or Windows 7
Visa and Master Card payments are now accepted!
Using DNA to identify bloodstains? With the BackTrackTM Suite software the analyst can locate the sources of the blood by carrying out a Directional Analysis of the bloodstain patterns.
Don't make the mistake of going to court with a bloodstain evidence report that lacks a proper BackTrackTM analysis of the scene.
This site contains a description of Directional Analysis(c) and a discussion of the validity of this ingenious procedure.
Version 4.52 is now available on a CD along with a set of 17 training videos narrated by Dr Fred Carter that can be viewed on your computer monitor.
Included, at no extra charge, the Tracks program (Ver. 3.00) can simulate bloodstain patterns on vertical surfaces. This is a useful program for gaining insight into the physics of blood spatter and the mathematical implications of using strings.
The Canadian Society of Forensic Science has published a special edition of their Journal that is devoted to Bloodstain Pattern Analysis. (http://www.csfs.ca/journal/journ01.htm, see December 2001 ). One of the articles is my paper "The Directional Analysis of Bloodstain Patterns, Theory and Experimental Validation".
This article can now be referred to by BPAs as published proof that the BackTrack procedure is based on sound science and uses the latest digital imaging techniques with computers. Also it shows that the method is capable of reliable and accurate results. See also "Validation of the BackTrack Suite of Programs for Bloodstain Pattern Analysis" . Reference #5
Bloodstain Pattern Analysts and interested forensic investigators can receive a copy these papers by contacting me at email@example.com
Curvature of Flight Paths
When the flight paths of the blood droplets have significant curvature, the 2D convergence methods are only valid for horizontal surfaces (floors, ceilings, etc) and is not valid for vertical surfaces (walls, etc.). However, the 3D Directional Analysis(c) used here, works well for vertical surfaces. This method has the advantage that the errors due to the flight path curvatures affect only the height of the source location, causing it to become an upper limit rather than a definite height determination..
More Screen Shots ...
BackTrack/Images is used to analyze stain 10 for the impact angle alpha and the directionality angle gamma by fitting an ellipse to the image of the stain. BackTrack/Images produces a data file that can be read by BackTrack/Win.
Physics Resources - directory of Physics related websites.
Szigg.net - Web Directory
Purchasing information and prices.
E-mail address: firstname.lastname@example.org
Last revision: November 30 2010