Forensic Science

Original Powerpoint Adapted from Richard Saferstein

Prentice Hall and Mrs. Partridge LHS

Definitionfe-ren’ sik adj relating to, used in, or

appropriate for courts of law or for public discussion or argumentation

Latin forensis – public, of a forum

forensic science is the application of science

to criminal and civil laws.

Criminalistics

A body of knowledge concerning the recognition,

collection, identification, individualization, and evaluation of physical

evidence using the techniques of natural

science in matters of legal significance.

What a forensic scientist DOES!

She deals with life’s grimmest realities

dispassionately while never losing

sight of the feelings that keep her human

What a forensic scientist DOES A forensic scientist must be skilled in

applying the principles and techniques of the physical and natural sciences to the analysis of the many types of evidence that may be recovered during a criminal investigation.

A forensic scientist may also provide expert court testimony.

Is it “forensics”? The “science” of forensic science Scientific method

Observing Problem Researching problem – survey the scene Hypothesizing – who committed the crime based

on evidence Testing – analyze the evidence to see if it

implicates a suspect If answer is wrong, start over

Avoid forming conclusions too early in an investigation. You may miss/neglect evidence.

Is it “forensics”? Forensic Process R.I.I.R.

Recognition Scene survey, documentation, collection &

preservation Identification

Comparison testing Individualization

Evaluation, interpretation Reconstruction

Reporting & presentation -

Scope of Forensic Science Criminalistics – the

application of physical sciences to criminal investigation

Specialties Medicine Anthropology Odontology Entomology Legal Document analysis Ballistics Facial reconstruction others

History of Forensic Science Many believe that

Sir Arthur Conan Doyle popularized scientific crime-detection methods through his fictional character Sherlock Holmes

History of Forensic Science Holmes applied new, developing

principles of serology, fingerprinting, firearm ID, and questioned-document examination long before their value for first recognized and accepted by real criminal investigators

Doyle’s first novel, A Study in Scarlet, has examples of his ability to describe scientific methods of detection, years before they were actually discovered and implemented

History of Forensic Science Forensic Science has been around nearly 900 years First recorded application of medical knowledge to the

solution of a crime was in 1248 1836 - James Marsh detected arsenic poisoning in

connection with a criminal investigation 1839 - Mathieu Orfila, toxicology, perfected techniques to

trace poisons 1879 - Alphonse Bertillon developed anthropometry, body

measurements to distinguish individuals Late 1800’s - Alexandre Lacassagne, ballistics and

bloodstain patterns

History of Forensic Science 1892 – Francis Galton developed methodology of classifying and filing fingerprints

1901 Karl Landsteiner discovered blood typing

1915 Leone Lattes devised a simple procedure for determining blood group

History of Forensic Science 1910 Edmund Locard, exchange

principle, 1st forensic science journal (Locard’s Exchange Principle—states that when a criminal comes in contact with an object or person, a cross-transfer of evidence occurs)

1924 August Vollmer, LAPD crime lab (oldest)

1932 FBI laboratory, fingerprints 1980’s DNA testing ()

Forensic Science in the USA Federal (FBI, DEA,

secret service, ATF) State (coroner,

medical examiner) Local (sheriffs,

police) Private (DNA labs)

Stop/warn

Coroner vs. Medical Examiner

Coroner – an elected official with death investigation duties

Medical Examiner – an appointed government official, always a physician and often a forensic pathologist, with duties of investigating sudden and unexpected deaths or deaths from injuries

Basic Services Provided by Crime Laboratories Physical Science Unit (drugs,

glass, paint, soil, explosives) Biology Unit (DNA, hairs, fibers,

plants) Firearms Unit (ammunition) Document Examination Unit

(handwriting, authenticity) Photography Unit (all photo;

presentations for court)

Optional Services Provided by Crime Laboratories

Toxicology Unit (drugs, poisons)

Latent Fingerprint Unit Polygraph Unit Voiceprint Analysis

Unit Evidence Collection

Unit

Envelope containing anthrax spores sent to Senator Tom Daschle shortly after 9/11. A variety of forensic skills used to examine it:

Law and Science (see guided notes)

The philosophical foundation of

the criminal justice system

remains to PROTECT the

innocent and to ensure that

the TRUTH EMERGES for any

matter before the court,

thereby ensuring that JUSTICE

IS DONE

Bill of Rights The Bill of Rights was

designed to expressly reserve certain powers to the citizens against the Federal Government

The Bill of Rights was not always understood to apply to the rights of citizens when actions involved the state

Precedent Cases Mapp v. Ohio, 1961: The

4th Amendment prohibits unreasonable searches

Robinson v. California, 1962: The 8th Amendment protects against cruel and unusual punishment

Gideon v. Wainwright, 1963: The 6th Amendment provides the right to counsel

Application of the Bill of Rights Amendments 1 through 14 apply to all

states, saying:

The Federal constitution provides the minimum protection. The state may provide greater protection but not less.

()

4th Amendment The right of the people to be

secure in their persons, houses, papers and effects against unreasonable search and seizures shall NOT be violated

No Warrants shall be issued but upon probable cause, supported by an Oath or affirmation, particularly describing the place to be searched and the persons or things to be seized

4th Amendment The 4th Amendment requires

that a valid warrant be issued prior to any search

A warrantless search is

Presumptively Unreasonable!

4th Amendment A valid warrant is

required for all unreasonable searches and seizures

Required to obtain a warrant

Probable cause Oath or affirmation Particular description area to

be searched What you’re searching for

Evidentiary Information

The probable cause clause requires that the police establish the trust worthiness of the information

that they base their observations that a

crime has been committed.

Two Types of Information Sources

Citizen or victim Both are generally

trustworthy No need to collaborate

The informant Credibility of informant

is important because informants may also be involved in criminal activity themselves

Two Prong Test For An Informant Reliability of information

Established by identifying how, when, and where the informant received his information

Credibility of the Informant Established by identifying the informant,

determining his self-interest, & identifying the past accuracy of the informant

Warrant SpecificityThe following must also be

included on the warrant:

Place - specific Time Items searching for Neutral authority –

judges permission

Area of ProtectionAreas of reasonable

expectation of privacy: Car Office House

Abandoned property does not require a search warrant.

Warrantless Entry Consent Plain view Exigent circumstance

Fire scene Belief that a person within is in

need of immediate aid Cars parked in a public place

Inventory of locked areas Caretaker Search incident to custodial

arrest Arrestee’s clothing

$5,040.00 In Hidden Compartment

Chain of Custody Once the items have

been seized and inventoried, chain of custody must be fully documented

Specifies: who seized it, and every subsequent individual who has custody or control of the item

Packaging of Evidence The CSI must make sure that

the evidence is properly packaged according to the recommendations of the forensic laboratory

When evidence is presented in court, it should be professionally packaged and presented

It it’s necessary to repackage evidence, the original packaging must be included in or securely attached to the new package Not like this!

Team Work

Forensic scientists work as members of a

larger team, perhaps other specialized

scientists, law enforcement investigators,

prosecutors, defense attorneys, judges,

juries and the media.

Law and Science

Lawyers have an OBLIGATION to conduct a spirited defense of the accused, especially if they are guilty

Law and Science In contrast, forensic

science remains JUSTIFICATION based, reaching the truth, dependent upon evidence and data

All scientists are required to uphold a high ethical standard, bound to combine scientific skills with a sworn duty to the public good

Law and ScienceFrom crime scene to conviction, a good forensic

scientist will be teaching others, an ability that

requires patience and the communication of

complex principles in simple terms.

Law and ScienceFrye Standard

(named after the 1923 case)

Requires the court to determine whether the scientific theory and/or scientific method used

to generate evidence are generally accepted as reliable

in the scientific community

Law and ScienceFrye test:

1. Is the scientific theory generally accepted in the scientific community? (experts)

2. Is the scientific method used generally accepted in the scientific community? (papers, books on the subject)

3. Has the technique been applied correctly?

Law and ScienceDaubert v. Merrel Dow

Pharmaceutical, Inc

Trial judges must assume the ultimate

responsibility for acting as a ‘gatekeeper’ in

judging the admissibility and reliability of

scientific evidence presented in their courts

Law and ScienceDaubert Ruling Guidelines

1. Whether the scientific technique/theory can be (has been) tested

2. Whether the technique/theory has been subject to peer review and publication

3. The technique’s potential rate of error4. Existence & maintenance of standards

controlling the techniques operation5. Whether the scientific theory /method has

attracted widespread acceptance within a relevant scientific community

An Expert’s Role By law, only a judge can

declare someone an expert witness

Attorneys offer an expert witness to the court to give opinions within their expertise

Used to help clarify facts or educate the jury

Court Advice For a Forensic Scientist

“Whereof one can not speak, thereof one must remain silent.”

- Ludwig Wittgenstein