Slide 1

What is Forensic Science? the study and application of science to matters of law it examines the associations among people, places, things and events involving crimes Slide 2 criminalistics the scientific examination of physical evidence for legal purposes criminology includes the psychological angle: studying the crime scene for motive, traits, and behavior that will help to interpret the evidence Slide 3 evidence: anything that tends to establish or disprove a fact (testimony, documents, objects, matter) ballistics: the science that deals with the motion, behavior and the effects of projectiles (firearms, bullets) Slide 4 A forensic scientist studies the different types of evidence found at a crime scene and testifies as an expert witness at a trial or hearing - presents data, weighs evidence, gives an impartial opinion to the court Slide 5 Basic Services Provided by the Crime Lab Physical science unit Chemistry Physics Geology Biology unit Firearms and ballistics unit Document examination unit Photography unit The most common types of evidence examined are drugs, firearms, and fingerprints. Slide 6 CRIME SCENE TEAM A group of professional investigators, each trained in a variety of special disciplines Team members: First police officer on the scene Medics (if necessary) Investigators Medical examiner or representative (if necessary) Photographer and/or field evidence technician Lab experts: pathologistserologist DNA experttoxicologist forensic odontologistforensic anthropologist forensic psychologistforensic entomologist firearm examinerbomb and arson experts document and handwriting expertsfingerprint expert Slide 7 METHODOLOGY OF FORENSICS Locard principle (Edmond Locard 1900s) a criminal can be connected to a crime by trace evidence collected at the crime scene whenever two objects come into contact there is always a transfer of matter Slide 8 forensic scientists must be methodical in their work general observations to specific that link evidence to a crime and a suspect Slide 9 Scientific Method (as it pertains to criminalists) 1. Observe a problem or questioned evidence and collect objective data. 2. Consider a hypothesis or possible solution. 3. Examine, test, and then analyze the evidence. 4. Determine the significance of the evidence. 5. Formulate a theory based on evaluation of the significance of the evidence. Slide 10 Types of Crimes infraction: minor offense or petty crime; penalty is usually a fine misdemeanor: minor crime punishable by fine or jail felony: major crime punishable by fines and/or more than one year in prison Slide 11 Federal Rules of Evidence In order for scientific evidence to be admitted in a court of law, it must be: probative: actually proves something material: addresses an issue that is relevant to the particular crime Slide 12 Admissibility of Evidence The Frye Standard From the 1923 case Frye v. United States Scientific evidence is allowed into the courtroom if it is generally accepted by the relevant scientific community. The Frye standard does not offer any guidance on reliability. The evidence is presented in the trial and the jury decides if it can be used. Slide 13 Admissibility of Evidence The Daubert Ruling From the 1993 case Daubert v. Dow The judge decides if the evidence can be entered into the trial. Admissibility is determined by: Whether the theory or technique can be tested Whether the science has been offered for peer review Whether the rate of error is acceptable Whether the method at issue enjoys widespread acceptance Whether the theory or technique follows standards Slide 14 Facets of Guilt To prove a case, the MMO must be established; it must be shown that the suspect had: motive - person had a reason to do the crime (not necessary to prove in a court of law) means - person had the ability to do the crime opportunity - person can be placed at the crime scene