400 likes | 548 Views
New Seating Assignments. Please find your seat. Homework: Thank you note Crime Scene Investigation Study Guide Use PowerPoint for review . Agenda: 2/13 . Test next week: Crime Scene; Evidence; Labs; http ://jsmithforensic.cmswiki.wikispaces.net /
E N D
New Seating Assignments • Please find your seat
Homework: • Thank you note • Crime Scene Investigation Study Guide • Use PowerPoint for review Agenda: 2/13 Test next week: Crime Scene; Evidence; Labs; http://jsmithforensic.cmswiki.wikispaces.net/ • Warm-up: Read career article (Cornell notes and summarize) • Officer Allen’s talk: Key information • Crime Scene Investigation • Evidence collection, packaging & chain of custody • You as a Crime Scene Investigator –Day 1 • Pictures of a Crime Lab - Columbus, Ohio
A crime scene investigation consists of recognizing, documenting, and collecting evidence from the crime scene.Multi-disciplinary approach
Officer Allen’s talk – Key Information . • TIME IS IMPORTANT. • Make sure the crime scene is BIG enough. • Separate any unwanted visitors from the crime scene. • Get names, telephone numbers, addresses & stuff. • He does NOT determine the body is dead. • Protect the crime scene. • GSR - Gun shot residue. • If it’s a homicide, he calls Chief Monroe. • Secure the crime scene. • If you aren’t questioning the suspect about the crime, you don’t have to read him his Miranda rights. • Charlotte has a fully certified crime lab. • They re-create the crime scene. • We need a timeline of events that occur during the investigation. • Mark areas & take pictures. • A detective directs the case.
PROCESSING ACRIME SCENE • Isolate and secure the scene • Document the scene • Search for evidence • Collect and package evidence, maintaining the chain of custody • Submit evidence to the crime lab
COLLECTING AND PACKAGING EVIDENCE • One evidence collector - collects, marks, seals, and preserves in a consistent manner • Different types of evidence require specific or special collection and packaging techniques • Most fragile is collected and packaged first • The body is the property of the coroner or medical examiner. The collection of evidence on the body is done by that department
Packaging EvidenceTo identifyTo preserve To protect Primary package Secondary package Subsequent packaging
CHAIN OF CUSTODY There must be a written record of all people who have had possession of an item of evidence. • The evidence container must be marked for identification • The collector’s initials should be placed on the seal • If evidence is turned over to another person, the transfer must be recorded.
CRIME SCENE RECONSTRUCTION Hypothesis of sequence of events that occurred before and through out the crime Stages • Data collection • Hypothesis formation • Examination, testing and analysis • Determination of the significance of the evidence • Theory formulation
THE MEDICAL EXAMINER AND THE CORONER • A medical examiner is a medical doctor, usually a pathologist and is appointed by the governing body of the area. • A coroner is an elected official who usually has no special medical training. • In four states, the coroner is a medical doctor.
MEDICAL EXAMINER’S RESPONSIBILITIES • Identify the deceased • Establish the time and date of death • Determine a medical cause of death—the injury or disease that resulted in the person dying • Determine the mechanism of death—the physiological reason that the person died • Classify the manner of death • Natural • Accidental • Suicide • Homicide • Undetermined • Notify the next of kin
INVESTIGATORS “The wise forensic investigator will always remember that he must bring all of his life experiences and logic to find the truth. This means common sense, informed intuition, and the courage to see things as they are. Then he must speak honestly about what it adds up to.” —Dr. Henry Lee Chief Emeritus for Scientific Services and the former Commissioner of Public Safety for the state of Connecticut
You as a crime scene investigator • Components: • Description of a Well-known Case • Description of the Duties of First Responder and Crime Scene Specialists • Your First Responder Story • Your team will develop a story of when the first responder came on to the scene. You will describe what she/he saw and then secured and preserved the crime scene. • Detailed Sketch of the Crime Scene • Evidence Collected and How it was Preserved
The crime lab A quick tour through the Columbus, Ohio Police Department Crime Laboratory.
Detailed and rigorous chain of custody of any evidence. • Most sealed in plastic, but DNA evidence is not sealed in plastic since it would degrade more quickly if sealed. • Even plastic will allow some moisture loss, so drugs in plastic will lose weight over time. • Many labs now using a LIMS (laboratory information management system) so evidence is barcoded, rather than have handwritten labels.
Documents lab Primarily handles falsified checks. A lot of work that is done in this lab is visual assessment bymagnified comparison of signatures, inks
Fingerprint lab • use fingerprint powder and magnification to see details. • Fingerprints can reveal drug use- metabolites react with antibodies used in fingerprint powder.
Fingerprint lab • Ninhydrin reaction with proteins in fingerprint requires reaction under chemical hood. • New labs have individual hood spaces for each reaction so there is no possibility of transfer of evidence
Alcohol lab • Runs hundreds of alcohol in urine tests at a time. • Head space gas chromatography used to determined percent alcohol content
DNA laboratory • Short tandem repeat (STR) process is done in this lab and is most prevalent in US • Work has to be done with care so that the material is not contaminated with other DNA. • How much is enough? A small stain on clothing, a single drop of blood, the root of a hair. TRACE evidence. • DNA linked to FBI database
Firearms • National Integrated Ballistics Information Network (NIBIN) used to identify bullets and casings
Comparison microscope used to examine bullets and casings to confirm if a particular gun was used.
Test fire evidence
Testing guns for the marks they leave on bullets and casings.
Cocaine and marijuana. First test done is a colorimetric spot test.
Researching Maryland • http://www.youtube.com/watch?v=1M_Kr1Y9etY • Crime Scene Investigation and Forensic Anthropology - YouTube