Forensic Science and the Law

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Forensic Scienceand the Law

• In school, every period ends with a bell. Every
  sentence ends with a period. Every crime ends
  with a sentence.
• Stephen Wright, comedian

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Laws that Pertain to the U.S. Criminal Justice
System

• The U.S. Constitution
• Statutory Law (is written law set down by a
  legislature)
• Common Law or Case Law
• Civil Law
• Criminal Law
• Equity Law
• Administrative Law

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Fourth Amendment

• The right of the people to be secure in their
  persons, houses, papers and effects against
  unreasonable searches and seizure, shall not be
  violated and no warrant shall issuue, but upon
  probable cause .
• Search warrant needed in most cases
• Warrantless search existence of emergency, need
  to prevent loss or destruction of evidence,
  consent by parties, part of lawful arrest

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The Bill of RightsGives individuals the right

• To be presumed innocent until proven guilty
• Not to be searched unreasonably
• Not to be arrested without probable cause
• Against unreasonable seizure of personal property
• Against self-incrimination
• To fair questioning by police
• To protection from physical harm throughout the
  justice process
• To an attorney
• To trial by jury
• To know any charges against oneself

• To cross-examine prosecution witnesses
• To speak and present witnesses
• Not to be tried again from the same crime
• Against cruel and unusual punishment
• To due process
• To a speedy trial
• Against excessive bail
• Against excessive fines
• To be treated the same as others, regardless of
  race, gender, religious preference, country of
  origin, and other personal attributes

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Miranda v Arizona

• In 1963, Ernesto Miranda, a 23 year old mentally
  disturbed man, was accused of kidnapping and
  raping an 18-year-old woman in Phoenix, Arizona.
  He was brought in for questioning, and confessed
  to the crime. He was not told that he did not
  have to speak or that he could have a lawyer
  present. At trial, Miranda's lawyer tried to get
  the confession thrown out, but the motion was
  denied. The case went to the Supreme Court in
  1966. The Court ruled that the statements made to
  the police could not be used as evidence, since
  Mr. Miranda had not been advised of his rights.

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Fifth Amendment the right against self
incrimination

• The following is a minimal Miranda warning
• You have the right to remain silent. Anything you
  say can and will be used against you in a court
  of law. You have the right to speak to an
  attorney, and to have an attorney present during
  any questioning. If you cannot afford a lawyer,
  one will be provided for you at the governments
  expense.

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Types of Crimes

• Infraction - Infractions are violations of law or
  ordinances that are typically pretty minor,. An
  infraction is less serious than a misdemeanor and
  may not  technically be considered  a crime,
  depending on the circumstances.  A person who
  commits an infraction will usually get a ticket
  or citation - not jail time or other heftier
  punishments. 
• Misdemeanor are more serious than infractions,
  but less serious than felonies.  Misdemeanors
  typically result in a heavier fine than what
  someone would pay if they committed an
  infraction or if sentenced to jail, for a term
  that is less than a year.  If a jail sentence is
  imposed, it is served at a local, city or county
  jail rather than a state or federal prison
  (penitentiary). 
• Felony are the most serious types of crimes, and
  each state has different punishments for these
  offenses.  A standard definition of a felony is
  any crime punishable by more than one year in
  prison.  Unlike misdemeanors, defendants
  convicted of felonies serve their sentences in a
  state or federal prison rather than a local, city
  or county jail. 

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Processing Physical Evidence

• In order for evidence
• to be admissible, it
• must be
• Legally obtained
• Probativeactually prove something (relevant)
• Identify the item
• Maintain the chain of possession

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Federal Rules of Evidence

• is a code of evidence law governing the admission
  of facts by which parties in the United States
  federal court system may prove their cases, both
  civil and criminal. The Rules were enacted in
  1975, with subsequent amendments.1

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Admissibility of Evidence

• 1923 Frye v. United States
• Scientific evidence is allowed into the courtroom
  if it is generally accepted by the relevant
  scientific community. The Frye standard does not
  offer any guidance on reliability. The evidence
  is presented in the trial and the jury decides if
  it can be used.

• 1993 Daubert v. Dow
• Admissibility is determined by
• Whether the theory or technique can be tested
• Whether the science has been offered for peer
  review
• Whether the rate of error is acceptable
• Whether the method at issue enjoys widespread
  acceptance.
• Whether the opinion is relevant to the issue
• The judge decides if the evidence can be entered
  into the trial.

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Facets of Guilt

• Try to prove
• Meansperson had the ability to do the crime
• Motiveperson had a reason to do the crime (not
  necessary to prove in a court of law)
• Opportunityperson can be placed at the crime

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What is testimonial evidence?
Testimonial evidence includes oral or written
statements given to police as well as testimony
in court by people who witnessed an event.
Eyewitness accounts can be a useful tool in
helping investigators with analyzing a crime
scene, but are not viewed to be highly reliable.
In addition, eyewitness identifications (right or
wrong) can have a big influence on the outcome of
an investigation or trial. People are likely to
view the same scene in different ways depending
on their positions, line of sight, familiarity
with the area, and other factors that can
interfere with a persons ability to remember
details.
The Bunny EffectCBS News Video
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Memory Challenge
Directions You will have 30 seconds to view the
next screen. Try to memorize all 20 items you
see! You are NOT allowed to write anything down
You CANNOT talk to anyone else.
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Items to remember ...
Neuroscience for Kids - http//faculty.washington
.edu/chudler/puzmatch1.html
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What do you remember?
How did you do? All 20 Awesome 15-19
Great 10-14 Pretty swell 5-9 Could be better
4 or Less Wake up
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Did you know?
According to The Innocence Project (2008)
"Eyewitness misidentification is the single
greatest cause of wrongful convictions
nationwide, playing a role in more than 75 of
convictions overturned through DNA testing."
Still, the criminal justice system profoundly
relies on eyewitness identification and testimony
for investigating and prosecuting crimes (Wells
Olson, 2003).
What factors affect a persons memory and their
ability to identify a suspect?
Source http//www.helium.com/items/1276135-accura
te-eyewitness-accounts
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Witness Factors

• Age may play a role in the accuracy of an
  eyewitness statement or identification of a
  suspect. Studies have shown that when a lineup
  contains the actual culprit, both young children
  and elderly perform well, but when the lineup
  does not contain the culprit there is a higher
  rate of mistaken identifications.
• The race of the witness may also play a role. The
  Cross Race Effect (CRE) is a phenomenon in which
  people are better at recognizing faces of their
  own race rather than those of other races.
• The use of drugs can alter a persons ability to
  recall the events of a crime even after they are
  no longer under the influence.
• A persons memory of an event can be influenced
  by other witnesses, investigators, and/or the
  media. Investigators use open-ended questioning
  and follow procedures for conducting line-ups to
  limit their influence on a witness memory of an
  event or identification of a suspect.

Source http//www.helium.com/items/1276135-accura
te-eyewitness-accounts
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Crime Scene Suspect Factors

• A crime that is extremely traumatic for an
  eyewitness may affect his/her recall of the
  event. For example, a witness confronted with a
  weapon tends to focus on the weapon rather than
  the perpetrators face.
• Someone who is able to focus on a perpetrator's
  face for a minute or longer will tend to have a
  more accurate memory than someone who saw the
  person for only a few seconds.
• Studies have shown that faces that are either
  highly attractive, highly unattractive, or
  distinctive are more likely to be accurately
  recognized. Simple disguises, such as hats or
  sunglasses, can interfere with accurate
  eyewitness identification. However, body
  piercings and tattoos increases the likelihood of
  an accurate identification.
• The time of day in which the crime occurred as
  well as a persons view of the scene may affect
  what a he/she is able to see. In addition, a
  person who is familiar with the area in which the
  crime took place, may have a better recall of the
  positions of the victims or suspects.

Source http//www.helium.com/items/1276135-accura
te-eyewitness-accounts
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Crime Scene Challenge

• Now that your eyes and brain are warmed up, lets
  test your observation skills a bit more.
• You will have 2 minutes to study the photograph
  of a crime scene on the next slide.
• Try to pay attention to details as you will be
  asked 10 questions about the crime scene!
• You are not allowed to write anything down until
  after the time is up.
• Ready?

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(No Transcript)
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Do you remember?

• What color coffee mug was in the picture? Blue
  Red Yellow
• 2. When was the deadline? Yesterday
  Today Tomorrow
• 3. What time was on the clock on the wall?
  1040 1105 155
• 4. How many sticky notes were on the whiteboard?
  Four Six Eight
• 5. Which of the following was NOT in the picture?
  Stapler Trash Can Printer
•  6. What was the name on the plaque on the desk?
  Bill Brian Carl
•  7. What color was the victim's shirt? Black
  Blue Red
•  8. How many plants were in the picture?
  None One Two
• 9. What was the color of the marker in the desk
  drawer? Red Blue Green
• 10. Where was the book in the picture? On a
  box In the trash can Under the body