EvidenceEvidence

EvidenceEvidence

• What is the role of evidence in a court of law?

• Evidence does one of two things:

1. Links a person suspected of committing a criminal offense to a crime scene.

2. Corroborate (confirm) one’s testimony and exoneratinga suspect of committing a criminal offense.

“Sir, why is the victims blood on your clothes?” Obviouslythis person has some explaining to do.

EvidenceEvidence

• In a court of law there are two types of evidence which can bepresented to a jury.

• Testimonial Evidence

• Physical Evidence

EvidenceEvidence

• Testimonial Evidence is eyewitness accounts of events. It cancome in a written or spoken form.

Pros Cons

Jury’s are impressed when a storyis told to them by another humanbeing.

“I was the defendant enteringthe crime scene prior to the murder”

One’s memory can be faulty.

The time between an eyewitnessseeing an event and a trial may beseveral months or even years.

EvidenceEvidence

• Physical Evidence is something which has size, shape, anddimension.

• As the definition would imply it can be collected and analyzed.

• It is impossible to list all types of physical evidence which couldbe encountered at a crime scene, however here are some whichwe will look at throughout this course:

EvidenceEvidence• Blood, Semen, and Saliva. All suspected blood, semen, and salivapresent in a form to suggest a relation to the offense or persons involved in a crime.

• Documents. Any handwriting submitted so that source or authenticitycan be determined.

• Fibers. Any fiber whose transfer may be helpful in establishing arelationship between objects and/or persons.

• Hair. Any human or animal hair present which may link a person witha crime.

• Impressions. Tire markings, shoe prints, handprints, etc.

EvidenceEvidence• Fingerprints. All prints have a physical nature.

• Firearms and Ammunition. Any firearm, as well as discharged orintact ammunition, suspected of being used in a criminal offense.

• Tool Marks. Any object suspected of containing the impressionof another object that served as a tool in a crime.

• Explosives. Any device containing an explosive charge, as well asobjects that are removed from a crime scene containing residue ofthe explosive..

EvidenceEvidence

Types of Physical Evidence

1. Evidence which can be associated with a common sourcewith a extremely high degree of probability is said to possessIndividual characteristic.

Examples:

Fingerprints Bullet Striations Shoe Impressions DNA

AND…. MANY… MANY… MORE

Maggots

EvidenceEvidence

Types of Physical Evidence

2. Evidence is said to possess class characteristics when itcan be associated only with a group and never with a singlesource.

Examples:

Dexter’s hair color.

Dexter’s eye color.

Dexter’s skin color.

Dexter’s cotton shirt.

Someone else’s blood on Dexter?

EvidenceEvidence

Class or Individual Evidence?

Denim Jeans? Class

Broken glass which can be pieced together? Individual

.45 Caliber Ammunition (unspent)? Class

.45 Caliber shell casing (spent)? Individual