Post on 08-May-2020
Introduction toForensics
Come in and get your notebooks
out. We have notes today!
What is FORENSIC SCIENCE?
Forensics….
* Forensics is the application of science to criminal and civil law enforced by police in a criminal justice system.
* Incorporates techniques of Chemistry, Biology, Physics, Geology, Computer Tech to determine value (significance) of crime scenes or evidence.
* Forensics has extended to areas of pathology, psychology, anthropology, odontology that are used in the capacity of law enforcement.
Forensics includes the application of a broad range of science to answer questions in the legal system.
Criminalistics vs Forensics You may hear the term “criminalistics and forensics used in this class. Although there
is overlap, the two terms are in fact different.
Criminalistics focuses only on the scientific approach to examine crime scenes and evidence (Bio, Chem, Phys, Geol, etc). Forensics uses a variety of techniques and
principles to study evidence. Forensics also incorporates psychology, accounting, computer science, etc.
FORENSICS Criminalistics
Criminalistics is only a branch of Forensic
Science.
Common Branches of Forensic Science
PathologyStudies injury patterns and
determines cause of death
OdontologyUses Dental
information to identify bodies
PsychiatricStudies human
behavior
Crime SceneExamines and collects
evidence in a crime scene.
Digital MediaPhotographs physical
evidence and examines computer records
BallisticsExamines fired guns
and ammunition
ToxicologyLooks into detection
of poisons
Questioned Documents
Analyzes ink, paper, toner and
handwriting
History of ForensicsYi Yu Ji - Coroner Solved a Case using Pigs
Chinese begin use of Fingerprints for Identification
Carl Wilhem Steel – First test that detects arsenic in corpses
Mathieu Orfila – Father of toxicology. Published a book on the effects of poisons on animals. Toxicology evidence first used in 1839
Forensic Photography Introduced- Recorded inmate pictures and crime scene photos.
Alphonse Bertillon – Father of Anthropometry – Used body measurements for identification. This was replaced by fingerprints.
First Use of Forensics
1850 - 1860
1814
700
1775
1879
History of ForensicsHans Gross – wrote a book about how science can help with criminal
investigations
Sir Arthur Conan Doyle- made foresnics popular with “Sherlock Holmes” Books. First to apply “Serology” (Study of bodily fluid)
Dr. Karl Landsteiner– First to discover that blood can be seperated into 4 types – A, B, O, and AB
Albert Osborn– Document Examination
Edmond Locard – Started first crime lab in an attic. Locard Exchange Principle states when two objects interact, they is an exchange of particles. So, all criminals pick up trace particles of the surrounding areas.
1893
1910
1910
1899
1901
Locard’s Exchange Principle"Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more, bear mute witness against him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value."
Beginning of “Trace Evidence”
History of ForensicsDr. Walter C. McCrone – Pushed for microscopy in Forensics. Using
microscopes to examine trace evidence.
Calvin Goddard – Ballistics – looking at marking made by guns on bullets and bullet casings
Sir Alec Jefferies – Invented DNA profiling. Revolutionized Forensic Science. In 1986, DNA was used in court for the first time.
1937
1940
1984
Introduction to Forensics
4 Major Crime Labs
Crime Labs are centers for both forensic investigation of ongoing criminal cases and research for new techniques for the future
The Crime Lab
FBI DEA AFT USPIS
FBI DEA AFT USPIS Federal Bureau of
Investigations
Largest Crime lab in the World
Used to Train personnel
Develops newest methods of testing
Drug Enforcement Administration
Analyzes drugs that are taken in violation
of Federal laws
Bureau of Alcohol, Firearms, Tobacco,
and Explosives
Examines weapons and explosives
Analyzes Alcohol and Tobacco
United States Postal Inspection Service
Investigates any crime involving the post
office
Although these labs exist, many local law enforcement jurisdictions (city, county, state) run their own independent crime labs
Services of The Crime LabPhysical Evidence Analysis Evidence Collection UnitBiology / Pathology Unit Ballistics UnitDocument Examination UnitPhotography UnitToxicology UnitLatent FingerprintingPolygraphVoiceprint Analysis
Basics of Forensic Law
Methods of Crime Solving
Confessions
Eye Witness Accounts
Physical Evidence
3 main methods to solve crimes
Trained law enforcement uses proper interrogation techniques. Ensures that confessions are free from coercion.
Trained law enforcement to properly questions eye witnesses without leading them into giving information.
Trained law enforcement collects evidence and ensures it follows the proper chain of custody.
Forensic Scientists focus on Analyzing Physical Evidence.
They may be required to testify at a trail or hearing.
They may train law enforcement in the collection and preservation of physical evidence.
Suspects may confess on their own or after being interrogated. Confessions can be tricky and still need to investigated. It is important that the suspect is reliable, mentally stable, and in no way coerced or feeling threatened to make a confession.
Confession
Types of
Witnesses Expert Witness
Lay Witness
must testify on events or observations that come from personal knowledge
(must be factual, no personal opinion of witness)
will need to be educated, have experience, and training relevant to the trial.
This person may express personal opinions to significance of special findings
Collection of Physical Evidence Whenever evidence needs to be collected, trained personnel must be called to the scene.
Crime Scene Units are trained to recognize and gather evidence. If CSU’s are not available, officers or detectives collect evidence.
Some police forces do not use crime scene units – this can lead to problems later if proper collection techniques are not followed or there is an inconsistences in evidence chain of custody.