Do now: What are the advantages to having physical evidence?

THE CASE: A single man is found dead, face down in the snow, far from his home. There are no tracks around him and it has not snowed for several weeks. Hundreds of people witnessed his death, but only he could have prevented it. THE MYSTERY: What was the man doing just before his death and how did he die? CLUES: It was windy and cold when the man died. The man paid to be where he was and was dressed warmly. The man was not wearing shoes. The man was engaged in a recreational activity. Just before he died, the man got a real lift. The man fell to his death.

Physical Evidence Characteristics Aim: What do we look for when analyzing physical evidence?

Analysis of Physical Evidence The forensic scientist must be aware of the judicial system’s demands and constraints in addition to being skilled in science. Procedures and techniques used must be based upon a firm scientific foundation. The scientist must never deviate from protocol! Must be meticulous and never creative! All analysis of evidence must satisfy criteria for admissibility. The scientist may be called upon to testify in court as to the methods used and conclusions drawn.

“Expert Witness” Knowledge due to training, experience, and education. Competency will be established based upon degrees, experience, publications, and professional affiliations. Will be cross examined to try and discredit testimony. Can never render any view with ABSOLUTE certainty Opinion must be based upon “Reasonable scientific certainty” from training and experience. Must be impartial to findings Must be an “advocate of truth” not a cause.

Why Analyze Evidence? To create a linkage- a connection between a suspect and a person, place, or object. To link multiple crime scenes to a single perpetrator. To reconstruct the crime. To determine who is being truthful and who isn’t To provide information in a court to result in a conviction or exoneration

How can Physical Evidence be seized? Search Warrants & The 4th Amendment Probable Cause Items and places included in the warrant are specific. Warrantless Searches –emergency, loss of evidence, arrest, consented search. 4th Amendment, 5thAmendment, & Miranda Rights

Collecting & Protecting the Evidence Chain of Custody must remain unbroken from “crime scene to courtroom.” Rule out outside or cross contamination Accounts for every person who handles evidence. Sometimes evidence is marked directly (shell casings) Majority of evidence are placed in evidence bags Marked and initialed by person who finds it. Case number, name & description of item, name of person who found it, names of witnesses to the discovery and recovery of the item, date, time, and location of the find. Sometimes special packaging is needed (Sealed glass tubes for dried blood.) This will be discussed separately for each unit Each person accepting (Kept to a minimum) evidence initials or signs & dates the evidence bag. They are now responsible for maintaining its integrity.

Collection of Evidence Primary Container Outer Container Proper marking of sealed evidence 2 1 3