FORENSIC SCIENCE

SRAVANI GHATTAMANENI L20357415

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Forensic Science

Definition: The application of scientific technology to supply accurate and objective information reflecting the events that occurred at a crime.

What does a Forensic Scientist DO???1. Analyze physical evidence2. Provide Expert Testimony3. Provide training in the recognition, collection and

preservation of physical evidence

Complex ReasoningIn Forensic Science

Deductive (reasoning from the general to the particular) and

Inductive Reasoning (reasoning from detailed facts to general principles)

Classifying Comparing and Contrasting Problem Solving Analyzing Perspectives Constructing Support Error Analysis

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Branches of Forensic Science

Physical science: Using chemistry, physics, and geology to ID and compare crime scene evidence

Biology: blood, body fluids, hairs and fibers, entomology

Pathology, psychology, odontology, any many more!

Why do we look to science for Why do we look to science for assistance in our legal system?assistance in our legal system?

• Increasing Increasing CrimeCrime Rates Rates• New or Changed New or Changed LawsLaws• New CrimesNew Crimes• New New WeaponsWeapons • Response to Response to PublicPublic Concerns Concerns• Response to Law Enforcement Response to Law Enforcement

Terrorism Forensics

New Weapons?New Weapons?

History & Development of Forensic Science

When in Rome… ““ForensicForensic”” comes from the comes from the LatinLatin word word ““forensisforensis””

meaning forum. meaning forum. During the time of the During the time of the RomansRomans, a criminal charge , a criminal charge

meant presenting the case before the public.meant presenting the case before the public. Both the person accused of the crime & the Both the person accused of the crime & the

accuser would give speeches based on their side accuser would give speeches based on their side of the story. of the story.

The individual with the best argument would The individual with the best argument would determine the outcome of the case. determine the outcome of the case.

First Known Forensic Science 3000 BC: China - A wife poisoned her husband and

burned his body. The coroner noted no ash inside his mouth and simulated the crime with dead & live pigs. The dead pig had no ash and the live pig did have ash in its mouth. The Wife confessed when shown the evidence.

Chinese first to see potential in fingerprints.

Sir Arthur Conan DoyleMystery author in late 1800Mystery author in late 1800’’ssPopularized scientific crime-detection Popularized scientific crime-detection

methods through his fictional character methods through his fictional character ‘‘Sherlock HolmesSherlock Holmes’’..

Mathieu Orfila Mathieu Orfila (1787-1853)(1787-1853)

““Father of Father of ToxicologyToxicology””Wrote about the detection of poisons & Wrote about the detection of poisons &

their effects on animals.their effects on animals.

Alphonse Bertillon ““Father of Father of AnthropometryAnthropometry”” Developed a system to distinguish one individual Developed a system to distinguish one individual

person from another based on certain body person from another based on certain body measurements.measurements.

Anthropometry

Francis Galton (1822-1911)(1822-1911)

““Father of Father of FingerprintingFingerprinting”” Developed fingerprinting as a way to uniquely Developed fingerprinting as a way to uniquely

identify individuals.identify individuals.

James Marsh Scottish Chemist

First to introduce chemical evidence of arsenic in a body during a trial in 1839.

Leone Lattes (1887-1954)(1887-1954)

““Father of Father of BloodstainBloodstain Identification Identification””He developed a procedure for determining He developed a procedure for determining

the blood type (A, B, AB, or O) of a dried the blood type (A, B, AB, or O) of a dried blood stain.blood stain.

Calvin Goddard (1891-1955)(1891-1955)

““Father of Father of BallisticsBallistics””Developed the technique to examine Developed the technique to examine

bullets, using a comparison bullets, using a comparison microscope, to determine whether or microscope, to determine whether or not a particular gun fired the bullets.not a particular gun fired the bullets.

Albert Osborn (1858-1946)(1858-1946)

““Father of Father of DocumentDocument Examination Examination””His work led to the acceptance of His work led to the acceptance of

documents as scientific evidence by the documents as scientific evidence by the courts. courts.

Walter McCrone (1916-2002)(1916-2002) ““Father of Father of MicroscopicMicroscopic Forensics Forensics””He developed & applied his microscope He developed & applied his microscope

techniques to examine evidence in countless techniques to examine evidence in countless court cases.court cases.

Hans Gross (1847-1915)(1847-1915) ““Father of Forensic PublicationsFather of Forensic Publications””Wrote the book on applying all the different Wrote the book on applying all the different

science disciplines to the field of criminal science disciplines to the field of criminal investigation. 1893investigation. 1893

Edmond Locard(1877-1966)

““Father of the Crime LabFather of the Crime Lab”” In 1910, he started the In 1910, he started the 11stst crime lab in an crime lab in an

attic of a police station in Paris, France.attic of a police station in Paris, France.With few tools, he quickly became known With few tools, he quickly became known

world-wide to forensic scientists & criminal world-wide to forensic scientists & criminal investigators & eventually founded the investigators & eventually founded the Institute of CriminalisticsInstitute of Criminalistics in France. in France.

His most important contribution was the His most important contribution was the ““LocardLocard’’ss ExchangeExchange PrinciplePrinciple””

Locard’s Exchange Principle ““Every Contact Leaves a Trace..””He believed that every criminal He believed that every criminal

can be connected to a crime by can be connected to a crime by particles carried from the crime particles carried from the crime scene.scene.

When a criminal comes in When a criminal comes in contact with an object or contact with an object or person, a cross-transfer of person, a cross-transfer of evidence occurs. evidence occurs.

J. Edgar HooverJ. Edgar Hoover

“Father of the FBI” - Director of Federal Bureau of Investigation during the 1930’s

Hoover's leadership spanned 48 yrs & 8 presidential Hoover's leadership spanned 48 yrs & 8 presidential administrations. His reign covered Prohibition, the Great administrations. His reign covered Prohibition, the Great Depression, WWII, the Korean War, the Cold War, & the Depression, WWII, the Korean War, the Cold War, & the Vietnam War. Vietnam War.

He organized a He organized a nationalnational laboratory to offer forensic laboratory to offer forensic services to services to allall law enforcement agencies in the U.S. law enforcement agencies in the U.S.

VERY CONTROVERSIALVERY CONTROVERSIAL He exceeded & abused his authority with unjustified He exceeded & abused his authority with unjustified

investigations & illegal wiretaps based on political beliefs rather investigations & illegal wiretaps based on political beliefs rather than suspected criminal activitythan suspected criminal activity

FBI directors are now limited to 10-year terms FBI directors are now limited to 10-year terms

Sir Alec Jeffreys – DNAFirst to develop a DNA profile (DNA

fingerprint) 1984

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CORPUS DELICTI“Body of the Crime”

You must prove: that a crime occurred that the person charged with the crime was responsible for the crime

Top Reasons for Committing a Crime Money Revenge Sex Emotion--love, hate, anger

Source of Evidence Body Primary and/or Secondary Crime Scene Suspect(s)

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4 Major FEDERAL Crime Labs:

FBIDrug Enforcement Administration (DEA)Bureau of Alcohol, Tobacco, Firearms and

Explosives (ATF)US Postal Inspection Service

Most states also have their own, smaller crime labs

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General Crime Lab Servicesand the materials each unit analyzes

Physical Science Unit: drugs, glass, paint, explosives, etc

Biology Unit: blood and other bodily fluids Firearms Unit: ballistics, comparisons Document Examination Unit: handwriting,

typewriting, questioned documents (ransom notes, etc) Photography Unit: record all phyhsical evidence. Toxicology Unit: presence/absence of drugs Latent Fingerprint Unit: fingerprints Pathology Unit-

Application of Forensic Science Identification of Criminals or Victims Solving Mysteries

Past crimes (unsolved or wrongfully convicted)Cause, Location, Time of DeathPaternity cases--------

Cyber crimes------------| Corporate Crimes (Enron) Voice Analysis

Applications of Forensic Science Application of DNA as evidence Prevention vs. Reaction Catastrophes & Wars

ID remains of victims (either civilian or soldiers)ex. Holocaust or Katrina

Military & International ForensicsTerrorism The search for WMD’sstockpiled or stored weapons from past wars

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Forensic Pathology

Investigation of sudden unnatural, unexplained or violent deaths

Answer the questions:Who is the victim?What are the injuries, when did they occur, and how

were they produced?5 manners of death: natural, homicide, suicide,

accident, undetermined

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Crime Scene Team

A group of professionals investigators, each trained in a variety of special disciplines.Team Members

First Police Officer on the scene Medics (if necessary) Investigator(s) Medical Examiner (if necessary) Photographer and/or Field Evidence Technician Lab Experts

pathologist serologistDNA expert toxicologistforensic odontologist forensic anthropologistforensic psychologist forensic entomologistfirearm examiner bomb and arson expertdocument and handwriting experts fingerprint expert

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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 LeeChief Emeritus for Scientific Services and the former Commissioner of Public Safety for

the state of Connecticut

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First Officerat the Scene

A Assess the crime scene

D Detain the witness

A Arrest the perpetrator

P Protect the crime scene

T Take notes

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Eye Witness

“Perception is reality.”As a result an eye witness may

not be the best source of crime scene information.

A police composite may be developed from the witness testimony by a computer program or forensic artist.

Faces Composite Programby InterQuest

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Crime SceneSearch Patterns

Spiral Grid

TWO of FOUR PATTERNS

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Crime SceneSearch Patterns

Strip or Line Quadrant or Zone

TWO of FOUR PATTERNS

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Crime SceneSketch

Date: August 14, 2001 Criminalist: Ann WilsonTime: 11:35 Location: 4358 Rockledge Dr

St. Louis, Mo.

A. Couch/sofa

B. Female body

C. Knife

D. Over turned Lamp

E. Chairs

F. Table

G. Fireplace

cD

E

EE

EE

A G

F

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Crime Scene Mapping(outdoors)

Azimuth--uses a compass beam to determine the location of each piece of evidence

Triangulation--uses two points at the crime scene to map each piece of evidence

Coordinate or grid--divides the crime scene into squares for mapping.

Suspended Polar Coordinate--for use in mapping evidence in a hole

Baseline--set a north/south line and measures each piece of evidence from this line.

AZIMUTHDetermines:

•Direction•Distance•Elevation

TRIANGULATION

Measure from A to B and then to the evidence in a triangular shape.

Coordinate or Grid Mapping

Set a north/south line from a datum point established by a GPS. Make it a perfect square (4 x

4) by shooting the hypotenuse and setting in stakes every foot or meter.

Measure and map the location of each piece of evidence. Then collect evidence and place in containers by grid.

Baseline Mapping

Set a north/south line from the furthest most points of the crime scene. Then measure each piece of evidence from that baseline. Evidence will need a numerical measurement where the piece begins, ends and in the middle.

Evidence Baseline

Suspended Polar Coordinate

Measure and map each layer of evidence as you move down the hole. Use the compass readings from the top to measure degrees and a tank dipping line to measure depth.

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MAPPING TECHNOLOGY

The latest technology includes this Nikon Tsunami with computer. The exact location of all crime evidence can be determined and directly loaded into a computer to produce a crime scene map. Cost = $35,000 for the set.

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Physical EvidenceTransient Evidence--temporary;

easily changed or lost; usually observed by the first officer at the scene

Odor--putrefaction, perfume, gasoline, urine, burning, explosives, cigarette or cigar smoke

Temperature--of room, car hood, coffee, water in a bathtub; cadaver

Imprints and indentations--footprints; teeth marks in perishable foods; tire marks on certain surfaces

Markings

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Physical Evidence (cont)

Pattern or Transfer Evidence--produced by direct contact between a person and an object or between two objects. There are several ways (at least 7) of classifying evidence. In this class, we will use:BiologicalChemicalPhysicalMiscellaneous

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Biological Evidence

Blood Semen Saliva Sweat/Tears Hair Bone

Tissues Urine Feces Animal Material Insects Bacterial/Fungal

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Chemical Evidence

Fibers Glass Soil Gunpowder Metal Mineral Narcotics Drugs

Paper Ink Cosmetics Paint Plastic Lubricants Fertilizer

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Physical (impression)

Fingerprints Footprints Shoe prints Handwriting Firearms

Printing Number restoration Tire marks Tool marks Typewriting

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Miscellaneous

Laundry marks Voice analysis Polygraph

Photography Stress evaluation Pyscholinguistic analysis Vehicle identification

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Physical Evidence (cont)

Conditional Evidence--produced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances within a particular event.Light--headlight; lighting

conditionsSmoke--color, direction of travel,

density, odorFire--color and direction of the

flames, speed of spread, temperature and condition of fire

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Conditional Evidence (cont.)

Location--of injuries or wounds; of bloodstains; of the victims vehicle;of weapons or cartridge cases; of broken glass, etc.

Vehicles--doors locked or unlocked, windows opened or closed; radio off or on (station); odometer mileage

Body--position; types of wounds; rigor, livor and algor mortis

Scene--condition of furniture, doors and windows; any disturbance or signs of a struggle.

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Evidence Characteristics

Class--common to a group of objects or persons

Individual--can be identified with a particular person or source.

ABO Blood Typing Blood DNA Typing

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Medical Examiner vs the Coroner

A medical examiner is a medical doctor, usually a pathologist and is appointed by the governing body of the area. There are 7 medical examiners in the state of Missouri and 400 forensic pathologists throughout the U.S.

A coroner is an elected official who usually has no special medical training. In four states the coroner is a medical doctor.

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Medical Examiner’sResponsibilities

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

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THE BODYRigor Mortis

Temperature Stiffness Time Since of body of body Death

•Warm

•Warm

•Cold

•Cold

•Not stiff

•Stiff

•Stiff

•Not stiff

•Not dead more than 3 hrs

•Dead between 3 and 8 hrs

•Dead 8 to 36 hours

•Dead more than 36 hours

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THE BODYLivor Mortis

Livor mortis is the settling of the blood, causing the skin to change colors.

Lividity indicates the position of the body after death. When lividity becomes fixed, then the distribution of the lividity pattern will not change even if the body’s position is altered.

Lividity usually becomes fixed between 10 and 15 hours after death.

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THE BODYAlgor Mortis

Algor mortis is body temperature.

Average human body temperature: 98.6 F (37 C)

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Time Frame of Death

Condition Appearance Periphery blood drying 30 min to 2 hrs Blue-green discoloration of skin

Right and left area of abdomen 24 hours Entire abdomen 36 hours

Bloating 36 to 48 hours Skin slippage 4 to7 days Absence of smell from bones more than 1 year

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Time Frame of DeathEyeball Changes

Condition Appearance Cornea drying (eyes open) minutes Cornea drying (eyes closed) 2 hours Corneal cloudiness (eyes open) less than 2 hours Corneal cloudiness (eyes closed) 12 to 24 hours Eyeball collapse more than 24 hrs

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One can die of a massive hemorrhage (the mechanism of death) due to a fall (cause of death) as a result of being pushed (homicide), jumping (suicide), falling (accident), or not being able to tell which (undetermined). All of which are manners of death.

THEREFORE,

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CRIME

+ =

What Happened?

Why Did ItHappened?

Who DidIt?

Crime Scene Evidence Collection Witness, Suspect and Motive Development

Post Scene Evidence Processing Cause, manner, time of death

Investigative Stage Profiling

Means Motive Opportunity

Identificationand Arrest of

Suspect

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Forensic Investigations

Include some or all of these seven major activitiesRecognition--ability to distinguish important

evidence from unrelated materialPattern recognitionPhysical property observationInformation analysisField-testing

Preservation--collection and proper preservation of evidence

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Investigations (cont) Identification--use of scientific testing

Physical propertiesChemical propertiesMorphological (structural) propertiesBiological properties Immunological properties

Comparison--class characteristics are measured against those of know standards or controls; If all measurements are equal, then the two samples are considered to have come from the same source or origin.

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Investigations (cont.) Individualization--demonstrating that the sample is

unique, even among members of the same class. Interpretation--gives meaning to all the information Reconstruction--reconstructs the case events

Inductive and deductive logicStatistical dataPattern analysisResults of laboratory analysis

Final thoughts - Videos

Nicole Brown Simpson Murder – 3-D animation of a famous crime.OJ Simpson – The story of a real case drama with all the areas of forensic science represented.Body Farm - Dr. Bill Bass. UT research into the decay of humans, helps determine the time of death.

ACKNOWLEDGEMENTS

I would like to thank professor Dr.Shyam Shukla and all my friends.

THANK YOU

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