FINAL Flashcards
7 S’s of Crime Scene Investigation
- SECURING the crime scene
- SEPARATING the witnesses
- SCANNING the crime scene
- SEEING the crime scene
- SKETCHING the crime scene
- SEARCHING the crime scene
- SECURING and collecting evid
Securing the crime scene
Protects and preserves the crime scene (job of first responder)
Separating the witnesses
Prevents collusion and possible contamination of direct evid
Scanning the crime scene
Evaluate where pictures should be taken and determine general borders of the crime scene; evaluate for secondary crime scene
Seeing the crime scene
Take pictures from all angles- triangulation
Sketching the crime scene
Should be to scale
Notes possible positions of remains
Note other evid found at scene
Searching the crime scene for evid
Search methods should vary depending on size of crime scene
Evid is photographed and labeled
Securing and collecting evid
Evid should be packaged, sealed, catalogued.. chain of custody
2 types of search patterns
Linear and Spiral (?)
5 Patterns of the Medulla (know 2)
Hollow Absent Fragmented Segmental Solid
Locard’s principal of exchange
When a person comes into contact wiht an object or anotehr person, a cross transfer of physical evidence can occur- extent of transfer depends on intensity, duration, and nature of the contact
2 Methods plants use for pollination
Wind
Animals
3 Fingerprint patterns
Be able to recognize Loop Whorl and Arch
3 Types of fingerprints
Patent- visible pattern left on a smooth surface when fingers coated with blood, ink or some other substance touch a surface and transfer their print
Plastic- 3D fingerprint made in soft material such as clay, soap or putty
Latent- concealed fingerprints made visible thought use of powders or forensic techniques
4 components of blood
Plasma- 35% of total blood volume
Platelets- cause blood to clot
Red Blood Cells
White Blood Cells- only part that has DNA
What do white blood cells contain to make it used for DNA profiling?
DNA….
Antigens
Substance that provokes an immune response in the body
5 of population with A,B,AB,O blood types
A- 42% B- 12% AB- 3% O- 43% Rh+ 85% Rh- 15%
Trail of circular blood drops indicates what?
Passive- either standing still, or if moving, moving very slowly
Types of blood spatter (be able to recognize)
Wipe- object moves through partially dried blood
Swipe- Something wet with blood brushes against surface (feathered edge indicates direction)
Arterial Gush- blood exits the body under pressure from artery- peaks from heart contraction
Expired Blood- blood blown out of mouth/nose as result of air pressure (has bubbles)
Shadowing/Void- absence of blood in a pattern
3 factors determining toxicity of toxin
Dose Duration Nature of exposure Interactions w/ other meds By-products (ex wood alcohol)
When document is questioned, it is compared with what?
Exemplar
12 Characteristics of handwriting- know 4 (or 5)
- Line Quality
- Spacing
- Size consistency
- Pen Pressure
- Connecting letters
T/F: When suspect is creating a writing sample, the officer should let them know what it is being used for
FALSE
What are the 3 things that Biometric Signature Pads measure?
- Speed
- Pressure
- Angles
NOT RHYTHM
Is handwriting analysis by experts enough for a conviction?
NO
5 places where blowflies lay their eggs (besides in wounds)
Mouth Nose Ear Vagina Anus
Factors that affect the growth of the blowfly
Body clothed?
Body wrapped, frozen or inaccesible to insects?
Body burned?
Environment
Body exposed to wind, sun, shade?
Body exposed to toxins that affect growth rate?
Adequate food source for insects?
4 categories for manner of death that ME can determine
Natural
Accidental
Suicidal
Homicidal
When does Rigor Mortis peak?
12 hrs
At what point does coloration of skin from livor mortis become permanent?
8 hrs
What does a body look like 2 months after death?
Soft tissue mostly gone
Odors largely gone
Bones remain
4 rules of thumb determining how long the person has been dead
Body warm and limp- dead less than 3 hours
Body warm and stiff- dead 3-8 hours
Body cold and stiff- dead 8-36 hours
Body cold and limp- dead more than 36 hours
3 soil textures
Sand
Silt
Clay
Cadaver Decomposition Island
Area where the soil has been disturbed (from burying a body)- recognized by upturned soil and differentiation of plant life
4 components of cartridge
Primer powder
Gun powder
Bullet
Metal casing that holds it together
How does a gun work?
Trigger breaks and sends firing pin forward, firing pen strikes primer which initiates a controlled explosion, sending the bullet flying down the barrel
What causes rifling?
Elevation and lands in barrel of gun
What are the different ways to identify cartridge from a gun
Breach block mark
Primer strike marks
Ejection marks
T/F: Gunshot residue mark is left on the cartridge
FALSE
3 things to be learned about subject from shoe/foot impressions
Whether person walks on toes or heels Body weight If person tends to walk with toes pointed in/outward Shape of foot and wearer's activities Unique marks or holes
3 measurements taken from tire impressions
Turning Radius
Track width of front and back
Wheelbase (distance between tires)
