Speaking for the Dead:A Look at the Science of Forensic

Investigation

Xenora L. Collins

What is Forensic Science?

• Forensic Science is defined as,“The application of scientific principlesand methods to the investigation of crime.”

• Put another way, forensic investigation allows us to examine and analyze a crime scene through the steps of the scientific method, and answer our own questions about who, what, when, where, and how the crime was committed.

• Sound interesting? Read on.

Narrowing the Spectrum

• No thanks to TV series such as CSI and NCIS, forensic investigation has a new following, with a slightly Hollywood-ized twist. Despite Hollywood influence, shows like these incite curiosity.

• Forensics is a broad subject area. To narrow that subject, this project shall focus on one of the more popular studies in forensics, Bloodstain.

The ExperimentThe experiment will be to drop a solution of karo syrup and red food coloring to simulate blood from varying heights onto a piece of poster board. The resulting bloodstain will prove or disprove the hypothesis.

The Problem

• When observing the crime scene, will the height of the blood source (i.e. victim or weapon) effect the diameter of the resulting bloodstain?

The Hypothesis

• If the blood source is further from the surface, then the resulting bloodstain will be of a larger diameter.

Materials

Procedures

Note: In this experiment I went only to six feet due to the height of my apartment.

Variables

Data & ConversionEach measurement is averaged from the four original stains to reduce the risk of human error.12inDiameter=.5cm Radius=.25cmArea=.25 ²x3.1415927=.20sq.cm24inDiameter=.75cm Radius=.38cmArea=.38²x3.1415927=.45sq.cm36inDiameter=1.0cm Radius=.5cmArea=.5²x3.1415927=1.76sq.cm48inDiameter=1.5cm Radius=.75cmArea=.75²x3.1415927=1.76sq.cm60inDiameter=.1.25cm+spatter Radius=.62cmArea=.62²x3.1415927=.1.20 sq.cm+spatter72inDiameter=1.5cm+spatter Radius=.75cmArea=.75²x3.1415927=1.76 sq.cm+spatter

Graph

ConclusionHypothesis proven!

The Final Product

Sources

• Hallcox, Jarrett. Bodies We’ve Buried: Inside the National Forensic Academy, the World’s Top CSI Training School. Berkley Publishing Group, New York, NY. 2006. pg.181-189.

Acknowledgements

• Special thanks to my mother, Lori Collins, for assisting in photographing the experiment and tolerating “bloodstain” in her kitchen, of all places. You were really a great sport!