Forensics: Exam Prep Flashcards
What is Ballistics?
Ballistics is the study of firearms, bullets, and the travel of projectiles in flight
Dactylography
Is the study of fingerprints for identification purposes
Forensic Anthropology
Identification of persons or personal characteristics (sex, age, race, stature) based on body remains
Forensic Computer Science
Investigate criminal use of technology and electronic records
Forensic Engineering
Investigates transportation accidents, and materials failure cases, determine cause of building and structure collapses, etc
Forensic Entomology
Uses insects to determine the time of death of a corpse
Forensic Odontology
Dentists who specialize in identification perform bite mark analysis and dental identification when there is no other way for body identification
Forensic Pathology
Studying medical history, performing an autopsy, and collecting medical and trace evidence from the body helps to determine the cause and circumstance of death
Forensic Psychiatry and Psychology
Evaluate offenders and profile criminal cases
Forensic Serology
Identification of blood and other bodily fluids (semen, vaginal fluid, and saliva)
Forensic Toxicology
Determines toxic substances in the body includes drugs and poisons
Forensics of Criminalistics
The study and application of science to matters of the law
Polygraphy
Conducts polygraph (lie detector) tests; administered by people trained in investigation and interrogation
Who was Bertillion?
Father of Criminal Identification; developed anthropometry which uses body measurements to distinguish individuals
Who was Galton?
- Published Finger Prints
- Conducted first distinctive study of fingerprint and their classification, gave proof of their uniqueness
Landsteiner
- Discovered the ABO blood groups
Locard
- Created the first crime lab in France
- Developed the theory every criminal can be connected to a crime from evidence
Jeffreys
- The process of DNA fingerprinting was invented (DNA profiling)
What is direct evidence?
- First-hand observations
Ex. eyewitness, video, confessions
What is circumstantial evidence?
- Indirect evidence that can be used to imply a fact but does not directly prove it
Ex. finding a suspects gun at a crime scene is evidence that the suspect was there
What is individual evidence?
- Narrows down the suspect to one person or thing
Ex. DNA, fingerprint, handwriting and sometimes physical matches
What is class evidence?
- Narrow evidence down to a group of persons or things
Ex. blood type
What is trace evidence?
- Small but measurable amounts of physical or biological material
Ex. hair strand, fingerprint, DNA, drop of blood, pollen, gunshot residue
What are the seven S’s of CSI
- Secure the scene
- Separate the witnesses
- Scan
- See
- Sketch evidence
- Search for evidence
- Secure and collect evidence
Securing the crime scene
The first officer must make sure the scene is secure by making sure all individuals in the area are safe and second by preserving evidence
- Obtain medical assistance if needed
- Arrest suspects
- Isolate the area (exclude all unauthorized personnel, put up tape ropes barricades, prevent the loss of evidence)
- Request additional needs for investigations
What is the Innocence Project
- Was created in 1992, the goal was to reexamine post-conviction cases
- helps to exonerate the wrongfully accused
What to include in a crime scene sketch
- North should be labeled, and a scale of distance (how large the area is)
- All important objects (weapon and body) should be measured from the immovable landmarks
- Any other objects in the vicinity of the crime should be included in the sketch (ex. doors, windows, furniture, trees, vehicles, etc)
- Also include the date, time, location, case number, and names (sketches and verified)
What containers do you use for trace evidence?
Plastic pill bottles in which trace evidence can be hairs, glass, fibers, etc
Where are liquid and arson remains stored?
Airtight, unbreakable containers like metal paint cans to prevent evaporation
How should you package bloodstained materials?
Packaged in wrapping paper or paper bags to prevent mold
How should you package biological evidence?
Stored in breathable containers after air dried, packaged in paper bindles (druggists fold), then in paper or plastic container
What is the chain of custody?
- A list of all persons who came into possession of an item of evidence
- Each person who comes into contact with a piece of evidence must use proper procedure and protocol in order to maintain responsible handling of evidence from crime scene to courtroom in order for the evidence to be admissible in court
Locards Exchange Principle
- Whenever two objects come into contact with one another, a cross-transfer of physical evidence can occur
- The intensity, duration, and nature of the materials in contact determine the extent of the transfer
- Every criminal can be connected to a crime by small particles carried from the scene
- EVERY CONTACT LEAVES A TRACE
How to collect evidence
Packaging evidence:
- Metal or plastic forceps may have to be used to pick up small items
- Different containers for diff types of evidence (in other questions)
- An evidence log (includes a description of the evidence, name of the suspect, name of victim, date and time of recovery, the signature of the person recovering the evidence)
- Chain of Custody
How to prevent contamination
- Should wear gloves and avoid handling evidence, only touch in areas least likely to contain latent prints
- Keep cool and dry
- Keep out of direct sunlight
- Use facemasks
What are patent prints?
Visible prints, are left on a smooth surface when blood, ink, paint, grease, or some other liquid comes into contact with the hands and is transferred to that surface
What are plastic prints?
Indentations left in some soft material such as clay, putty or wax
What are latent prints?
Are not visible to the eye but can be made visible using chemicals and are caused by the transfer of oils and other body secretions from pores onto a surface
What is the fingerprint database?
Automated Fingerprint Identification System (AFIS), which provides digital, automated fingerprint searches, latent searches, and electronic storage of fingerprints and contains over 50+ million fingerprint records
What does Ninhydrin do?
- It is a chemical that bonds with the amino acids in sweat and will produce a blue or purple colour
- It is used to lift prints from surfaces such as paper
What does one use Cyanoacrylate Vapor for?
- It reacts with amino acids
- This fuming method (also called the superglue method) is a procedure that is used to develop latent prints on a variety of objects (turns prints white) like when glue dries
What is silver nitrate used for?
- Reacts with chlorine from salt (NaCl) in sweat and combines with silver nitrate to form silver chloride
- 2 part process: first spray, then expose to sun
- Turns black or red-brown
- For wood or styrofoam
What is iodine fuming used for?
- Iodine combines with carbohydrates
- In a vapor tent heat solid iodine crystals
- Produces brown print (fades quickly!)
- For paper, cardboard, unpainted surfaces
What is the scientific name and function of Red Blood Cells?
- Erythrocytes
- They have hemoglobin and carry oxygen and carbon dioxide
- Hemoglobin is the iron-containing protein that gives blood its red colour
- They have no nucleus and no nuclear DNA
What is the scientific name and function of White Blood Cells?
- Leukocytes
- They are an immune system cell which fights disease and produces antibodies
- Only cells that contain DNA (only useful blood cells for DNA profiling)
What is the scientific name and function of Platelets?
- Thrombocytes
- Small cell fragments that assist in blood clotting and repair damaged blood vessels
Where is DNA found in blood?
Only cells that contain DNA are the white blood cells
How does one determine blood type?
Look for A and B antigens that are found on the surface of RBC’s
If a person has A proteins they have what blood type…
A
If a person has B proteins they have what blood type…
B