INTRODUCTION TO FORENSIC SCIENCE GUIDED NOTES Name:_____________________

Forensic Science

Forensic science is the ______________________________________________________________.

Forensic science is a very broad discipline, encompassing both Criminalistics – _______________________________________________________________________________ Criminology - ________________________________________________________________________________

___________________________________________________________________________________________

Forensic Science CareersCrime Scene Investigators

_______________________________________________________________________________ _______________________________________________________________________________.

Some of the evidence may be analyzed by the CSI team that collected it, but much may be sent to laboratories or specialists.

Most jobs require a ______________________________________________________________. Some, but not most, require that you be a sworn police officer.

Pay is about $45k – $55 k

Criminalist / Forensic Scientist

_____________________________________________________________________________ _____________________________________________________________________________.

Often specialize in just one or a few areas.

Nearly all jobs require a __________________________________________________, and some require master’s or doctoral degrees

Some experts may help police only occasionally and have another job (e.g. doctor,

professor)

Most forensic scientists make ~50k-65k, but the head of a lab or some in-demand specialists may make $75k-$100 k

Forensic Specialties

_______________________ Determines a person’s competency to stand trial, sign documents, or make medical decisions; determines motivation of suicide victims, and provides psychological profiles of suspects.

________________________

Gathers evidence from the body and/or living victims. Reviews medical records, witness statements, police reports, conducts autopsies, and determines cause of death.

____________________ Examines plant fragments, pollen, or soil to place a suspect at a crime scene or to determine

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whether a body has been moved.

____________________ Determines the types of fluids present and matches samples of fluids to victims or suspects.

_____________________ Examines and identifies firearms, bullets, and shell casing, and searches for gun shot residue.

____________________ Examines finger, palm, and foot prints, and matches them to prints taken from suspects, other crime scenes, or databases.

____________________ Examines marks found on the crime scene and matches them to tools found with suspects.

_____________________ Uses insect larvae found in corpses to determine time of death and whether the body has been moved from one location to another

____________________ Determines the authenticity and authorship of various documents

____________________ Analyze and compare hair, fibers, glass, soils, and paints to determine their type and origin, and to place suspects at the crime scene

____________________ Identifies unknown bodies by comparing teeth with dental records or matches a suspect’s teeth with bite marks on the victim or other evidence.

____________________ Collects, protects, and transports evidence from the crime scene to the crime lab. May also sketch and photograph the crime scene.

_____________________ Examines skeletal remains to determine age, sex, and race of the deceased. May also identify types of injury / disease and establish time of death.

Forensic Pathologists

A physician with special training in pathology (disease)

___________________________________________________________________________________ ___________________________________________________________________________________

Other responsibilities:

Reviews medical history Reviews witness statements Performs autopsy Collects evidence (toxicology, microscopic examination of organs, DNA analysis, etc.) Writes a report, include an official cause of death Provides testimony in criminal court In complicated cases, a forensic pathologist may also be asked to examine and photograph the

crime scene himself. Most salaries are between $75k-$140k, but can be as high as $400k, especially in private sector

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Medical Examiners vs Coroners

The person _______________________________________ to perform autopsies and determine cause of death may be either a medical examiner or a coroner.

Medical examiners ___________________________________forensic pathologists

Coroners __________________________________________ forensic pathologists, or they may be doctors with a different specialty (e.g. obstetrics), or they may not even have any medical training at all.

Most counties have adopted the newer medical examiner system, but some rural areas still employ coroners.

Expert witnesses and the law

In any case involving a death, the _______________________________ will testify

Experts in other specialties may also be called to testify

It is the ________________ who decides ___________________________ to be considered an expert and ______________________ they are allowed to present

Legal precedent for expert witness testimony

Frye vs. United States (1923)

“Frye Standard”: expert testimony must be based on “______________________________ scientific principle” that is “________________________________” and has obtained “__________________________” in the scientific community

Daubert v. Merrell Dow Pharmaceutical, Inc. (1993)

“Rule 702” or “Daubert standard”

Explicitly states that it is up to ______________________________ whether to allow testimony

Offered judges the following guidelines for admissible techniques and theories

subject to testing and __________________________

___________________________

known __________________________

Attained widespread _______________________

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How do these two standards differ?

Other rules for expert witness testimony

Expert witnesses are ______________________ before the jury

What does this mean? Experts testify as to their ______________________, ___________________, and ____________________________ before presenting evidence.

Because they must explain complicated information, expert witnesses have much greater freedom in how they testify (i.e. they can _______________________, rather than just _____________________ __________________________________)

Types of Evidence – Direct vs. Indirect

__________________________ - Evidence that establishes a fact ______________________________ ___________________________

Example: ____________________________________________________________________

___________________________________ / circumstantial evidence - Evidence that only provides a ___________________________________ about a fact

Example: _____________________________________________________________________

Direct or Indirect?

Soil matching a crime location found on a suspect’s clothing Possession of an illegal substance Video of a person committing a crime Fingerprint at crime scene Fingerprints on the murder weapon DNA match to skin under victim’s fingernails

When could you argue that fingerprints on the murder weapon are direct evidence?

When could you argue that fingerprints on the murder weapon are indirect evidence?

What about skin under the victim’s fingernails? When is it direct? When is it indirect?

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Types of Evidence – Testimonial vs Documentary vs Physical

Testimonial evidence -- _________________________________

Documentary evidence - _________________________ relevant to a crime

Example: audio / video / written documents

Physical evidence -- any object or material relevant to a crime

Which type of evidence?

DVD stolen from a store Surveillance video of a robbery Crime scene photographs

Problems with eye-witness accounts

Most cases of wrongful imprisonment are due to mistaken eyewitness identification!

Eye witnesses may be wrong for many reasons:

Age / eyesight / hearing / alcohol or drugs

Stress / fear can focus and alter perceptions

Encounters may be brief or take place under poor conditions

New information may alter memories

Physical Evidence

Although ________________________, physical evidence is more reliable than eyewitness accounts.With enough physical evidence, a strong case can be made.

What can physical evidence show?

It can ______________________________ at a the crime scene or with the victim

It can help _______________________________ (for example, blood splatter can indicate the relative position of two people)

Can ___________________________________ / indicate that crime took place (e.g. finding gasoline at a fire indicates arson)

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Locard’s Exchange Principle:

“___________________________________________________________”

Every time someone goes somewhere, they leave behind physical evidence, and pick up trace evidence from their environment.

Probative Value

The more unique or _______________________________ a piece of evidence is, the better its _______________________________________ – the stronger proof it provides.

Example 1:

Finding that a suspect has the same brand of duct tape that was used in a crime is ok evidence.

BUT, if the torn end of the duct tape used in a crime exactly matches the torn end of the suspect’s role, that is much better evidence.

Example 2:

A footprint is found at a crime scene. The size matches a suspect, but it’s a common size. How can the print be further individualized?

Describing Evidence

Determine whether each type of evidence listed below is direct or indirect, physical or testimonial. For physical evidence, also describe additional details that might individualize the evidence and/or increase its probative value.

Survelliance camera videotape of a crime

Written contract

Blood stained clothing

Eyewitness account

Hair found at the crime scene

Crime Scene Investigation Procedure

Crime scene _______________________________________________________________

Primary crime scene _________________________________________________________

Secondary crime scene _______________________________________________________

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First responders _____________________________________________________________

Duties of the first responders

1. _____________________________________a. Establish scene diametersb. Identify potential hazardsc. Assist injured personsd. Search for and arrest suspect, if possible

What is the importance of scene management?

What is the drawback of first assisting injured persons?

2. _______________________________________a. Use physical barriers like vehicles and/or crime scene tapeb. Establish a crime scene security officerc. Keep a security log of all entries and exitsd. May use multilevel security

What important principle of forensics is related to the need to secure the crime scene?

What is the benefit of multi-level security?

Duties of the crime scene investigator

3. ___________________________________________________________• Review existing security and adjust if necessary• Detain, isolate, and interview witnesses and suspects• Coordinate team members

Why must witnesses be isolated?

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4. _________________________________________________

a. ___________________________________

Identify transient evidence, Note all areas (such as exits and entrances) that need special attention, Assess the need for specialty equipment or personnel, Take initial photographs and documentation

b. Document the scene with photographs, videotapes, and/or sketches c. Collect and package evidence

5. _____________________________________________________

6. _____________________________________________________

Why is chain of custody important?

Crime Scene Evaluation

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What was done correctly in Scenario A?

What was done incorrectly, and how could it have negatively affected the investigation?

What was done correctly in Scenario B?

What was done incorrectly, and how could it have negatively affected the investigation?

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What was done correctly in Scenario C?

What was done incorrectly, and how could it have negatively affected the investigation?

Crime Scene Search PatternsInvestigators often use geometric search patterns while searching for evidence to ensure that no evidence is missed.

The type of search pattern depends on the scene.

S

Jot down some benefits and drawbacks of each search pattern.

Take notes on the best use of each search pattern.

Grid –

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Spiral –

Parallel / Linear –

Zone / Quadrant –

Crime Scene Search Pattern Questions

1) Investigators believe a body may have been dumped in a large field. What search pattern be used?

1) Spiral

2) Grid

3) Parallel

4) Zone

2) A very high profile crime has been committed, and the police has been given a lot of resources and manpower to solve it. Which pattern is appropriate?

1) Spiral

2) Grid

3) Parallel

4) Zone

3) Police have a warrant to search a suspect’s car. Which pattern is appropriate?

1) Spiral

2) Grid

3) Parallel

4) Zone

Crime Scene NotesInvestigators take detailed notes on all of the following:

Step-by-step description of every action taken by investigators. Date, time, location, weather, environmental conditions Description of crime Location of evidence with reference to other fixed points Names of all people on the scene, including authorized personnel, witnesses, victims

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Crime Scene PhotosThe scene should be thoroughly photographed_______________ evidence collection.

Types of photos: • _________________________(exterior and interior)• _________________________• _________________________

Use scales and numbered placards with photos

Crime Scene Videos Crime scenes should be videotaped starting outside and moving in, all around the crime scene. Important details (time, place, and objective descriptions should be included, other narration should

be avoided. Should not include members of the investigative team.

Crime Scene SketchesRough sketches are done on the scene, and finished, to-scale sketches are completed later.

Crime scene sketches should be labeled with: A title A legend with letters, etc., for key

pieces of evidence Compass direction

Scale Case number Offense type Location

Example rough sketch Corresponding finished sketch

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In order to record exactly where the evidence is located, each and every piece of evidence must be measured from at least ________________________________.

This is called __________________________.

In practice, this is often most easily done by recording the ______________________________ coordinates / distances of every piece of evidence in the room.

Evidence Collection Often, just one person designated as evidence collector

Ensures that evidence is collected, packaged, and marked in a consistent manner Responsible that nothing is lost of contaminated Often wears face mask, lab coat, gloves, shoe covers, eye protection … why?

_________________________ collected first

Each piece of evidence is packaged separately

Most pieces of evidence will go in two containers, each sealed

Outer container will be labeled with:

Name of collector Date, time, and location of collection Type of evidence ________________________________ (list of all people who came in contact with a piece of

evidence)

Controls are taken for comparison

_________________________________________ – evidence with a known origin

Examples:

If a blood stain is found, blood would be collected from victims and suspects for comparison.

___________________________ are often done to collect DNA reference samples

_______________________________________ – sample of surface material close to where evidence is found

Example:

If arson is suspected, investigators will collect residue from an area believed to be exposed to an accelerant (e.g. gasoline) and also collect material from a nearby area not believed to be exposed to the accelerant

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Evidence PackagingDifferent containers are used for different types of evidence.

________________________________________________ should be dried and stored in porous materials (cardboard, paper) to prevent mold

Evidence from suspected __________________ should be stored in air-tight containers (such as tightly sealed jars) to prevent __________________________ from evaporating

Plastic pill bottles work great for small ____________________________________________________

Powders are typically stored using a ‘_________________________________________’

Warrants The fourth amendment protects against ‘unreasonable search and seizure’

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Warrants are obtained from a __________________, after police has demonstrated ____________________________, usually through a written ______________________, but sometimes over the phone.

Warrants have limited ________________________. If police go beyond the scope of the warrant that evidence is usually inadmissible in court. However, if evidence not included on the warrant is in ‘____________________________________’ during a search it is usually admissible in court.

Police must _______________________________________ a warrant search. However, if no one answers or if they are denied entry then they may break down the door to conduct the search. Also, judges may give written permission for police to just break in under circumstances suspected to be dangerous.

When are warrants not necessary?

During emergency circumstances

If necessary to prevent immediate destruction or loss of evidence

Search of person or property under immediate control of someone who has been lawfully arrested

“Stop & Frisk” – stopping and patting down someone reasonably suspected of a crime

Searches made by consent of party involved

Is a warrant necessary? Why or why not?

1. Police want to obtain a blood sample from a person who has been arrested.

2. Police come upon the scene of a homicide and search for the killer.

3. Police come upon the scene of a homicide, located within an office building, and search for trace evidence.

4. A store has just been robbed. Police stop and search the pockets of two teens loitering in the area.

5. Police have a warrant to search for an ax believed to be used in a murder. They search the house thoroughly, finding a baggie of drugs in a sock drawer. Are the drugs admissible?

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Is the evidence admissible? Why or why not?

6. Police pull over a person and ask for permission to search the car for a weapon. The person grants permission, and the police find a bag of drugs. Is the bag admissible in court?

7. Police have a warrant to search a home for a murder weapon and find a bag of drugs on the kitchen counter top. Is the bag admissible in court?

Knock and wait? Or not?

8. Police obtained a call about a domestic disturbance. When they arrive, they hear screams from inside.

9. Police have a warrant to search for drugs. They knock then hear the sound of a toilet flushing.

10. Police have a warrant to search for a weapon. They knock, then hear the sound of a toilet flushing.

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