investigations science or art?. 3.5 things solve cases they are?
TRANSCRIPT
INVESTIGATIONS
SCIENCE OR ART?
3.5 THINGS SOLVE CASES
THEY ARE?
WITNESS
PHYSICAL EVIDENCE
CONFESSIONS
.5INFORMANTS
– CANNOT BE USED TO PROVE
– NOT USUALLY USED IN COURT
SUCCESS OR FAILURE OF CASE
People commit crimes
“THINGS” become physical evidence
What is PHYSICAL EVIDENCE
PHYSICAL EVIDENCE---any object that can establish that a crime has been committed or can provide a link between a crime and its victim or between a crime and its perpetrator
CAN BE MEASURED
TYPES OF PHYSICAL EVIDENCE
Blood, semen, saliva Documents Drugs Explosives Fibers Fingerprints
Firearms, and ammunition Glass Hair Impressions Paint Soil and minerals Tool marks
WHOSE ARE THOSE ANYWAYS??
Individual characteristics---Properties of evidence that can be attributed to a common source with an extremely high degree of certainty.
HISTORY OF IT ALL
Sir Arthur Conan Doyle
A Study In Scarlet
1887
MID 1800’s NYPD set up a Rogue’s Gallery-1857
– Photographs of known offenders– Arranged by criminal specialty and height– Offenders grimaced, puffed their cheeks to change
their appearance
Rogue is slang for thieves, a wandering beggar, someone who wanders away
By 1858 had over 700 photographs
1884 Chicago established the first municipal Criminal Identification Bureau
1865 U.S. Secret Service was created by Congress to combat counterfeiting
Began guarding the president in 1903 after President McKinley was assassinated
1905 CA Bureau of Criminal Identification
First State Police Force in Pennsylvania Prohibition in 1920, Bureau of Internal
Revenue was responsible for enforcement Lodged in the Dept of the Treasury, they were
referred to as “T-men” 1908 the beginnings of the FBI 1932 FBI established a crime lab
1967 National Crime Information Center (NCIC) established by the FBI– Wanted persons– Stolen property
Guns Vehicles License plates
– Cannot do credit cards
“PACKING THE RECORD”
Get as much information as possible
NCIC INFORMATION CLEARING HOUSE
COMPUTERIZED NETWORK LINKED TO PDs TO PROVIDE INFORMATION ON
STOLEN VEHICLES WANTED PERSONS STOLEN GUNS OTHER CRIME
RELATED INFO
Oldest Forensic Lab LAPD---1932 Created by August Vollmer
Chief from Berkeley
LOCARDS EXCHANGE PRINCIPLE
Edmond Locard (1877-1966)
The exchange of materials between two objects that occurs whenever two objects come into contact with one another
TRACE EVIDENCE
PHYSICAL EVIDENCE THAT RESULTS FROM THE TRANSFER OF SMALL QUANTITIES OF MATERIAL
IDENTIFICATION
THREE MAJOR SCIENTIFIC SYSTEMS FOR PERSONAL IDENTIFICATION– DEOXYRIBONUCLEIC ACID (DNA) TYPING
– ANTHROPOMETRY
– DACTYLOGRAPHY
ANTHROPOMETRY
A system of identification of individual by measurement of parts of the body
ANTHROPOMETRY
Developed by Alphonse Bertillon (1853-1914) Father of criminal identification Bertillon system Every human being differs from every other
one in the exact measurements of their body and that the sum of these measurements yields a characteristic formula for each individual
Eleven physical measurements 1883 implemented on an experimental basis Combines full fact with profile pictures Ancestor of the “mug shot”
DACTYLOGRAPHY
Dates back to the First Century Romans Three categories of latent fingerprints
– Plastic prints—fingers touch against a surface such as newly painted surface, adhesive on envelopes and stamps, explosives, thick layer of dust, putty and adhesive tape
LATENT
LATIN WORD FOR
HIDDEN
Unique and Permanent
They develop at 12 weeks development Stresses in the uterus causes friction ridges to
develop Identical twins have same DNA but different
fingerprints---but may have same pattern types
FRICTION RIDGES
TINY RIDGES IN THE SKIN OF A FINGERPRINT ARE KNOWS AS;
FRICTION RIDGES
LOOPS
WHORLS
ARCHES
WHAT TO LOOK FOR
LOOPS 60-65% OF POPULATION
WHORLS 30-35%
ARCHS About 5%
– Contaminated/visible prints—fingers that have been contaminated with a matter touch a clean surface
– Latent/invisible prints—typically invisible to the unassisted eye. Created when the friction ridges deposit oils and body perspiration on a surface
PRINTS ARE MADE OF:
Natural source—Sweat (98% water and 2% oils) Salts and amino acids and vitamins cause the fingerprint to show when sprayed with a chemical
Environmental source—grease, dirt, pollen, etc.
DEVELOPING LATENT PRINTS
Traditional powders Fluorescent powders Chemicals Cyanoacrylate—Superglue fuming Ninhydrin Iodine
CHANGE THEM????
Impossible to obliterate all the ridge characteristics and scars just help to provide new characteristics for identification
LIVE SCAN FOR FINGERPRINTING
OPTICAL SCANNER
IAFIS FBI 1999
INTEGRATED AUTOMATED FINGERPRINT IDENTIFICATION SYSTEM
BRAIN FINGERPRINTING
OTHER TYPES OF IDENTIFICATION
DENTAL EVIDENCE & BITEMARKS– 1775 Paul Revere—was a dentist– John Wilkes Booth
mid 1960’s Armed Forces Used mainly for id of bodies 1970’s used for id of suspects
• HAIR• Area of the body and race• Manner removed• Shampoo residues• Bleached or dyed• Contaminants in the hair—blood, soil semen• If hair has been subject to trauma• Id of drugs ingested
BLOOD– Approx 10 pints of blood– Most common form of evidence– Human blood?– If recovered in liquid state can tell
Venous Fetal menstrual
HUMAN EXCRETIONS AND SECRETIONS– Saliva, urine, semen, perspiration, vaginal
secretions, feces and vomitus
LIPSTICK AND SECRETIONS– Everyone has unique lip prints that do not change
with age
FIREARMS
TOOL MARKS
DOCUMENTS
HANDWRITING AND HANDPRINTING
COMPUTERS
MOLECULAR STUCTUREDNA
DEOXYRIBONUCLEIC ACIDDEOXYRIBONUCLEIC ACID– Organic substance found primarily in the
chromosomes within the nuclei of cells. These molecules carry the body’s genetic information and establish each person as separate and distinct
DNA is three foot long chemical that is tightly wound inside the 46 chromosomes in each cell of the body
HISTORY OF DNA
• FBI first public sector crime laboratory to accept cases for DNA
• December 15, 1988
• Minnesota testing is done at the Bureau of Criminal Apprehension (BCA)
• Testing can take from 2 weeks to 2 months
CODIS 1998
COMBINED DNA INFORMATION SYSTEM
COMPARE AND EXCHANGE DNA PROFILES
WHAT TO DO FIRST????
OFFICER SAFETY
PUBLIC SAFETY
MEDICAL AID TO VICTIMS
DON’T LET EMS BECOME ERT’S
EVIDENCE
REDUCTION
TEAMS!!!!
IS IT A CRIME SCENE???
TREAT ALL CALLS FOR SERVICE AS A CRIME SCENE UNTIL CONCLUDED OTHERWISE
FIRST THING TO DO!!!!
SURVEY
SECURE
HOW TO SECURE THE SCENE
NATURAL BOUNDARIES
VEHICLES
TAPE
INITIAL PERIMETER--BROAD
WIDE LARGE BIG AMPLE SPACIOUS GENEROUS
WITHIN REASON
PERIMETERS
INNER– VERY RESTRICTED
OUTER– MAKE AS BIG AS POSSIBLE
SECURE WINDOWS AND DOORS WAS ANYTHING ALTERED??
ENTRY/EXIT LOG
PART OF SCENE DOCUMENTATION LOG FIRST TIME IN----LAST TIME OUT
EVERYBODY
QUICK SURVEY– NOTE PATHS THROUGH SCENE
START WRITING
MOVE NOTHING
FIELD NOTES
BEST WAY TO DOCUMENT DETAILS OF A CRIME SCENE
SUSPECT/VICTIM
OFFICER TO RIDE WITH ANYONE GOING IN THE AMBULANCE
OBTAIN STATEMENTS OBTAIN EVIDENCE
– CLOTHES
TECHNIQUE TO WORKING SCENE
FACTSWHAT DO YOU SEE
PROBABILITIES– WHAT MIGHT HAVE HAPPENED
SWAG– SILLY WILD _____ GUESSES
4TH AMENDMENT
MAKE SURE YOU ARE OBTAINING EVIDENCE LEGALLY– SEARCH WARRANT– VERBAL CONSENT
DOES EXIGENCY EXIST?
DOCUMENTING THE SCENE
TAKE PHOTOS ASAP
TAKE MORE THAN LESS
VIDEOGRAPHY– BE CAREFUL OF SOUND
ON OR OFF??
SEQUENCE WHEN TAKING PICTURES
OVERALL-----BROAD------STEP BACK
MEDIUM----CLOSER
CLOSE UP
LARGE AREA
OFFICER SHOULD UTILIZE A
SYSTEMATIC
SEARCH
CRIME SCENE SEARCH
CAN’T COLLECT IT IF YOU CAN’T FIND IT
Zone or Grid Method– Area to be searched is divided– Each person is assigned a part
SPIRAL OR CIRCULAR
Can be used for indoor scenes
Single searcher
LANE
MARK EVIDENCE
SKETCHING THE CRIME SCENE
Why sketch?– Scene will not be distorted– Can be as simple or complicated as needed– Sketch can show direction– Sketch will show more than the view from one
direction– Sketch can be used in conjunction with photos
RULES OF MEASURMENT
All measurements should be made from permanent objects
Verify all measurements—two officers check Always show north When measuring bodies get one measurement
at the head and one at the foot
CARDINAL RULE OF SKETCHING
DECIDE WHAT IS TO BE SKETCHED BEFORE TAKING MEASUREMENTS AND DRAWING OBJECTS
CROSS PROJECTION---MOST COMMON
EXPLODED, BIRDS EYE, OVERHEAD VIEW
Walls are folded down
Shows evidence on walls, such as blood spatter and bullet holes
TRIANGULATION
Straight line measurements taken from 2 fixed points
MOST COMMON IN OUTDOOR SCENES
COORDINATE
Right angles inside
Uses two walls as fixed points
REVIEW
CROSS PROJECTION
TRAINGULATION
COORDINATE
BE SURE TO ADD:
NOT TO SCALE
DUSTING
NOT THIS KIND
HOW TO OBTAIN PRINTS
SEACH SURFACE WITH A FLASHLIGHT– LOOK AT AN ANGLE– IF YOU SEE SOME---PHOTOGRAPH THEM
USE CORRECT BRUSH AND POWDER POWDER COLOR TO CONTRAST WITH SURFACE
NO NEED TO USE A LOT OF POWDER– VERY, VERY MESSY
APPLY LIFTING TAPE
COLLECT A LATENT PRINT
PHOTOGRAPH
DEVELOP
TAPE LIFT
CHAIN OF EVIDENCE/CUSTODY
Maintain scene security throughout process Document collections by recording its location,
date of collection and who collected it Chronological history of evidence Establish chain of custody
PACKAGING
NO BIOLOGICAL STUFF IN PLASTIC
PAPER ONLY
DRY BEFORE PACKAGING
SEAL TO PROVE INTEGRITY
PACKAGE TO PRESERVE AND FOR SAFETY
BIOHAZARDS---MARK
EXAMPLES OF:– BLOOD– SEMEN– TISSUE– BODILY FLUIDS– SHARPS
TRANSIENT EVIDENCE
EVIDENCE THAT WILL LOSE ITS VALUE IF NOT PRESERVED OR PROTECTED SUCH AS BLOOD.
LUMINAL
LIGHT PRODUCING CHEMICAL REATION AND THE HEMOGLOBIN IN BLOOD
CSI MIAMI LUMINAL AND BLOOD
Avoid excessive handling of evidence before and after collection
Transport and submit evidence for secure storage
WHAT NOT TO DO
NO SMOKING NO EATING NO USING THE BATHROOM DON’T TALK TO MEDIA NO TRASH
Take your trash out
Can reveal police actions
BEFORE YOU RELEASE A SCENE---- TALK ABOUT IT
MAKE SURE YOU ARE DONE
CARDINAL RULES FOR CRIME SCENE SEARCH
PROTECT THE CRIME SCENE OBTAIN EVIDENCE LEGALLY CONDUCT THE CRIME SCENE PROPERLY PRESERVE AND MAINTAIN CHAIN OF
CUSTODY
LEGAL JURISDICTION
Establishing the exact location where a crime occurred
Essential to establish jurisdiction of the crime
3 THINGS THAT SOLVE CASES
PHYSICAL EVIDENCE
WITNESSES
CONFESSIONS
INFORMANTS?????
INFORMANTS CANNOT BE USED TO PROVE AND MAY NOT GO INTO COURT
FINALLY……………
Criminal investigation is always in the process of evolving due to scientific, legal and social developments as well as changes in the behavior of criminals.