The Nature of Evidence A Guide to Legal Evidence & the Courts

Evidence: Any statement or object from which conclusions can be drawn

Circumstantial Evidence Information that seems to point to a perpetrator, including witnesses & documents Documents could be credit card receipts, telephone records or correspondence (mail or )

Physical Evidence Actual objects that are associated with the crime & can be linked to the perpetrator Can include blood, hair, fibers, DNA, etc.

Class Evidence Evidence that can be linked to a GROUP of people Example: hair, fiber, blood type

Individual Evidence Evidence that can be linked to ONE individual person Example: fingerprint, DNA

“Discovery” Each attorney is required to submit information regarding facts and expert information BEFORE the trial. This includes a list of witnesses.

Science Admissibility Standards Frye Standard Federal Standard Daubert Versus Merrell Dow

Frye Standard The court must decide if the questioned scientific procedure, technique, or principles are “generally accepted” by a meaningful section of the scientific community General acceptance is usually shown through expert testimony, books/documents/articles, as well as prior judicial decisions

Federal Standard More flexible than Frye Standard Does not rely only on “general acceptance” Describes expert testimony Witness is considered an “expert” based on knowledge, skill, experience or training May testify if testimony is based on facts or data, reliable methods were used, and the expert applied them to the facts of the case

Daubert vs Merrell Dow Landmark Supreme Court ruling (1993) Judges in federal court must assume the role of “gatekeeper” in the admissibility and reliability of scientific evidence Has the technique or the theory been tested Has it been subject to peer review and publication Potential rate of error Standards controlling the technique Widespread acceptance within the scientific community

Expert Witnesses An individual whom the court determines possesses knowledge relevant to the trial that is not expected of the average person

Laws & Crimes Law: codes of behavior with penalties for infractions Civil Law: lawsuits for injuries, traffic violations, contracts, punishable by fines Criminal Law: punishable by fines, jail time, community service, possible death

Crime Violation of a local, state, or federal law Must have a “victim”, a “perpetrator” and a “crime scene”

Misdemeanor Minor crime Punishable by fines & jail time of less than one year Examples: theft, minor assault, license violations

Felony Major crime Punishable by larger fines & time in prison Examples: murder, rape, armed robbery, drugs, fraud, auto theft

Locard’s Exchange Principle Whenever 2 objects come in contact with one another, there is an exchange of trace materials between them.