Intro Forensic Science

Intro Forensic Science
MR.BASILE Intro Forensic Science

What is Forensic Science?

What is Forensic Science?
Answer : Application of Science to help resolve matters of 1) Criminal Law 2) Civil Law Yes that is right….The Law! So you like Science…me too! But let’s start our journey into Forensic Science looking at the blending of the two disciplines. Let’s start with a bit of background in the Law!

Criminal Justice and the Law
Different Types of Law * The Constitution - supreme body of laws *Administrative Law – rules established by agencies – like the IRS or SSI *Civil Law – private law – deals with contracts and property * Criminal Law – public law – deals with offenses deemed offensive against society or individuals · Felony – a major crime such as rape, murder, armed robbery, serious assaults, dealing illegal drugs, auto theft, or forgery…penalties are normally 5 years to life in jail · Misdemeanor – minor crime such as theft, minor assault, battery, or possession of illegal drugs…penalties are normally less then one year in jail and a fine of $250 - $2500 Infractions – petty crime such as jay walking, littering or traffic violations…penalties are typically a small fine.

Steps in Criminal Procedure to Pursue Justice
These steps may vary slightly in different jurisdictions but here is a generic version of events.

These steps may vary slightly in different jurisdictions but here is a generic version of events. 1) A Crime is committed! EEEE GADS! 2) The police investigate – information is collected 3) Crime scene is documented and searched for evidence (This is our job as a forensic Scientist) 4) A suspect may be identified 5) All information is put into a report 6) If there is enough evidence – an arrest warrant is issued

These steps may vary slightly in different jurisdictions but here is a generic version of events. 1) A Crime is committed! EEEE GADS! 2) The police investigate – information is collected 3) Crime scene is documented and searched for evidence (This is our job as a forensic Scientist) 4) A suspect may be identified 5) All information is put into a report 6) If there is enough evidence and probable cause– an arrest warrant is issued 7) Suspect is arrested – the person is “booked” (define) and read their Miranda Rights (define) 8) Person is brought in for arraignment (define) within 72 hours – person is informed of charges and pleas GUILTY, NOT GUILTY or NO CONTEST (define) 9) A person then goes to a preliminary hearing - if they plead GUILTY or NO CONTEST … they receive their sentence. If they plead NOT GUILTY … the judge or grand jury decides on if there is enough evidence for trial, sets bail and a court date. ** Plea bargaining (define) can occur at many places in this process – 90% of cases are plea bargained __________________________________________________________________________________________________________

Federal Rules of Evidence
These rules govern what evidence is admissible and how it can be used in court.

These rules govern what evidence is admissible and how it can be used in court. The evidence must be : probative – it must prove something material – it must be relevant and significant to the crime *** hearsay is not admissible – it is what others have said being restated by someone…Gossip!!!!

These rules govern what evidence is admissible and how it can be used in court. The evidence must be : probative – it must prove something material – it must be relevant and significant to the crime *** hearsay is not admissible – it is what others have said being restated by someone…Gossip!!!! Scientific Evidence Two legal decisions have influenced what scientific evidence is allowed in courts The Frye Standard – (1923) – the scientific evidence must be generally accepted as true by the community as a whole to be acceptable in the court of law. The Daubert Ruling – (1993) - scientific evidence is getting to complex so guidelines were offered: ~The scientific theory must be testable ~Other experts must be able to review the theory to be sure it is valid ~The rate of error must be given (percentage error) ~The technique must follow standards ~The court must decide whether the theory has widespread acceptance inside a specific scientific community

Forensic Labs (Crime Labs)
Physical Science lab – examine drugs soil, glass, paint, blood spatter patterns, trace evidence Ballistics lab -examine tool marks, weapons, firearms and bullets Document Examination lab – examines handwriting, typewriting, word processing, computer applications, paper and ink Biological Lab -examine body fluids, DNA, blood factors, hair, fibers, and plant life Photography Unit- examines photographs and video/audio. Specifically are the ones who document the crime scenes. Toxicology unit- determine the amount and type of drugs or foreign substances within the blood stream Fingerprint unit – find and lift prints from the scene. Then inspect them and compare them to a database to identify a suspect Polygraphs unit- lie detector unit (dated) Arson unit- investigation of fires. How they are started/ what accelerant was used/ even investigate if a explosive was used.

Forensic Labs (Crime Labs)
Forensic Scientists use crime labs to evaluate evidence ~ found at the federal, state and local levels ~ most labs within a state are used for regions within state ~ larger cities have their own labs (examples New York, Los Angelos) Interesting facts ~ FBI is the largest crime lab in the world ~ Drug Enforcement Agency (DEA) runs a lab for Dept of Justice ~ Bureau of Alcohol,Tobacco, and Firearms (ATF) runs a lab for Dept of Treasury ~ US Postal Service runs a lab handling crimes in the mail ~ US Fish and Wildlife runs a crime lab

Methodology of the Forensic Scientist
And of course the is how we examine the evidence using the …

Methodology of the Forensic Scientist
And of course the is how we examine the evidence using the … Scientific Method observe the problem collect data and evidence consider a hypothesis or solution to solving the problem Examine, test, and analyze the evidence to refute or support the hypothesis Use deductive reasoning to determine the significance of the evidence Evaluate and verify evidence…All possible errors must be stated because someone’s life or liberty is in your hands.

Part 2 – Types of Evidence

Part 2 – Types of Evidence
Two main types of Evidence Testimonial Evidence – a statement made under oath, such as eyewitness testimony. Physical Evidence – an object or material that is relevant to a crime (tangible, large or small)

Testimonial Evidence Interesting Facts…
Jury’s are heavily influenced by eyewitness accounts

Testimonial Evidence Interesting Facts…
Jury’s are heavily influenced by eyewitness accounts Most known cases of an innocent person going to jail is because of mistaken eyewitness identification

Reliability of the Eyewitness
Factors that influence:

Factors that influence: The type of crime it is and how it was seen by the witness Serious crime? Weapon involved? Is the witness physically similar to the suspect? Was it a stressful situation

Factors that influence: The type of crime it is and how it was seen by the witness Serious crime? Weapon involved? Is the witness physically similar to the suspect? Was it a stressful situation Characteristics of the witness Adult vs. children? Alcohol, drug involvement? Poor eyesight or hearing? Head injury?

Factors that influence: The type of crime it is and how it was seen by the witness Serious crime? Weapon involved? Is the witness physically similar to the suspect? Was it a stressful situation Characteristics of the witness Adult vs. children? Alcohol, drug involvement? Poor eyesight or hearing? Head injury? Manner in which the information is retrieved Interviewing techniques used? Open ended questions…not leading questions

Factors that influence: The type of crime it is and how it was seen by the witness Serious crime? Weapon involved? Is the witness physically similar to the suspect? Was it a stressful situation Characteristics of the witness Adult vs. children? Alcohol, drug involvement? Poor eyesight or hearing? Head injury? Manner in which the information is retrieved Interviewing techniques used? Open ended questions…not leading questions Witness’s prior relationship with the accused Does the witness know the suspect?

Factors that influence: The type of crime it is and how it was seen by the witness Serious crime? Weapon involved? Is the witness physically similar to the suspect? Was it a stressful situation Characteristics of the witness Adult vs. children? Alcohol, drug involvement? Poor eyesight or hearing? Head injury? Manner in which the information is retrieved Interviewing techniques used? Open ended questions…not leading questions Witness’s prior relationship with the accused Does the witness know the suspect? Length of time between the offense and the identification How long has it been since the crime?

“Perception is reality.”
A police composite may be developed from the eyewitness testimony by a computer program or forensic artist. But the bottom line in eyewitness testimony is…. “Perception is reality.” And as a result of the influences in eyewitness memory… physical evidence becomes critical!

Value of Physical Evidence
Physical Evidence - object or material that is relevant to a crime (tangible, large or small)

Physical Evidence - object or material that is relevant to a crime (tangible, large or small) Generally more reliable than testimonial remember our eyewitness testimonies in class and no 5th amendment rights

Physical Evidence - object or material that is relevant to a crime (tangible, large or small) Generally more reliable than testimonial remember our eyewitness testimonies in class and no 5th amendment rights Can prove that a crime has been committed example - gasoline at a scene of an arson

Physical Evidence - object or material that is relevant to a crime (tangible, large or small) Generally more reliable than testimonial remember our eyewitness testimonies in class and no 5th amendment rights Can prove that a crime has been committed example - gasoline at a scene of an arson Can corroborate (support) or refute testimony can test blood stain to prove the suspects claim it is his own not the victims

Physical Evidence - object or material that is relevant to a crime (tangible, large or small) Generally more reliable than testimonial remember our eyewitness testimonies in class and no 5th amendment rights Can prove that a crime has been committed example - gasoline at a scene of an arson Can corroborate (support) or refute testimony can test blood stain to prove the suspects claim it is his own not the victims Can link a suspect with a victim or with a crime scene a broken piece of glass found on suspect that matches the headlight of a hit and run

Physical Evidence - object or material that is relevant to a crime (tangible, large or small) Generally more reliable than testimonial remember our eyewitness testimonies in class and no 5th amendment rights Can prove that a crime has been committed example - gasoline at a scene of an arson Can corroborate (support) or refute testimony can test blood stain to prove the suspects claim it is his own not the victims Can link a suspect with a victim or with a crime scene a broken piece of glass found on suspect that matches the headlight of a hit and run Can establish the identity of persons associated with a crime fingerprints, DNA, handwriting at the crime scene

Physical Evidence - object or material that is relevant to a crime (tangible, large or small) Generally more reliable than testimonial remember our eyewitness testimonies in class and no 5th amendment rights Can prove that a crime has been committed example - gasoline at a scene of an arson Can corroborate (support) or refute testimony can test blood stain to prove the suspects claim it is his own not the victims Can link a suspect with a victim or with a crime scene a broken piece of glass found on suspect that matches the headlight of a hit and run Can establish the identity of persons associated with a crime fingerprints, DNA, handwriting at the crime scene Can allow reconstruction of events of a crime what happened, sequence of events

Physical Evidence - object or material that is relevant to a crime (tangible, large or small) Generally more reliable than testimonial remember our eyewitness testimonies in class and no 5th amendment rights Can prove that a crime has been committed example - gasoline at a scene of an arson Can corroborate (support) or refute testimony can test blood stain to prove the suspects claim it is his own not the victims Can link a suspect with a victim or with a crime scene a broken piece of glass found on suspect that matches the headlight of a hit and run Can establish the identity of persons associated with a crime fingerprints, DNA, handwriting at the crime scene Can allow reconstruction of events of a crime what happened, sequence of events Provide a powerful interrogation tool police can ask better questions knowing specific information

Physical Evidence - object or material that is relevant to a crime (tangible, large or small) Important point!!!! You hear people classically say “Oh their case is based on purely circumstantial evidence.” Implying it is not good evidence for the case. Physical evidence is circumstantial evidence! They are the same thing…circumstantial evidence is physical evidence that implies a fact. For physical evidence to be useful it has to imply a fact…otherwise it is useless

Physical Evidence The main goal of the forensic science team is …

Physical Evidence The main goal of the forensic science team is …
to link the victim, suspect, and crime scene with evidence. Crime Scene Victim Suspect

Physical Evidence The main goal of the forensic science team is …
to link the victim, suspect, and crime scene with evidence. Victim Crime Scene Suspect

Physical Evidence Evidence
The main goal of the forensic science team is … to link the victim, suspect, and crime scene with evidence. Victim Crime Scene Evidence Suspect The Forensic Team Coroner or Medical Examiner Law enforcement officials Forensic scientists Crime Scene Investigators Lab technicians

FIRST IMPORTANT PRINCIPLE OF FORENSICS
A fundamental principle of every crime scene studied is… Locard’s Principle “Whenever two objects come into contact, there is always transfer of material.” The methods of detection may not be sensitive enough to demonstrate this, or the decay rate may be so rapid that all evidence of transfer had vanished after a given time. Nonetheless, the transfer has taken place.

SECOND IMPORTANT PRINCIPLE OF FORENSICS
Class Evidence vs. Individual Evidence

Class Evidence vs. Individual Evidence
Class Evidence – common to a group of objects or persons

Class Evidence – common to a group of objects or persons These fibers are class evidence—there are millions like them.

Class Evidence – common to a group of objects or persons Individual Evidence – can be identified with a particular person or a single source These fibers are class evidence—there are millions like them.

Class Evidence – common to a group of objects or persons Individual Evidence – can be identified with a particular person or a single source These fibers are class evidence—there are millions like them. The large piece of glass fits to the bottle—it is individual evidence

PART 3: HISTORY A bit of history
Early origins of ‘forensics’ appear in ancient Egypt and later in Mesopotamia. In the 6th century first book in forensic medicine in China, followed by the first forensic textbook in 12th century Office of the coroner was established in England in the 9th century

Some known and less known historic figures in development of forensics
Sir Arthur Conan Doyle Sci-fi author in late 1800’s Popularized scientific crime-detection methods through his hi his fictional character. Mathieu Orfila the father of toxicology Wrote about the detection of poisons & their effects on animals. Alphonse Bertillon the father of Anthropometry Developed a system to distinguish one individual person from another based on certain body measurements.

Some known and less known historic figures in development of forensics
Francis Galton “Father of Fingerprinting” Developed fingerprinting as a way to uniquely identify individuals. Leone Lattes He developed a procedure for determining the blood type (A, B, AB, or O) of a dried blood stain Calvin Goddard Developed the technique to examine bullets, using a comparison microscope, to determine whether or not a particular gun fired the bullets

Edmond Locard “Father of the Crime Lab”
In 1910, he started the 1st crime lab in an attic of a police station. With few tools, he quickly became known world- wide to forensic scientists & criminal investigators & eventually founded the Institute of Criminalistics in France. His most important contribution was the “Locard’s Exchange Principle”

Locard’s Exchange Principle
“Every Contact Leaves a Trace.” He believed that every criminal can be connected to a crime by particles carried from the crime scene. When a criminal comes in contact with an object or person, a cross-transfer of evidence occurs. 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. - Professor Edmond Locard

Let’s Dive Into Forensics… But first a quote to keep in mind at all times
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. - Professor Edmond Locard

Intro Forensic Science

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