SCI 220 EXAM 4 WITH COMPLETE
SOLUTIONS
When a shirt partially reflects the color red, what does this mean? - Answer- That the
shirt is absorbing all other colors, but the red is being reflected
Light is transmitted through - Answer- -Glass, Water, or Liquids
-Handkerchief, Camera filters
Conversion of light is when - Answer- Light can be absorbed and transmitted at a
different wavelength (fluorescence)
Fluorescence means - Answer- from one state to another
Luminescence - Answer- -light emitted by means other than burning, such as chemical
or biochemical action or radiation (causes other than heat)
-Encompasses both fluorescence and phosphorescence
Fluorescence - Answer- A material that glows only while it is currently being stimulated
by a stronger light (ALS or FLS)
Phosphorescence - Answer- A material that contains some of the radiation they
absorbed from stimulating light and continues to glow after the light has ceased (Glow in
the dark toys)
Chemiluminescence - Answer- A material glowing because of a chemical reaction
(Luminol, glow sticks)
Using a stimulating light in the range of ________ - _______ nm such as an ALS is
helpful when searching for ________ ________ - Answer- 400-700nm
bodily fluids
How does the alternative light source work? - Answer- -The stain will absorb the light
-The initial energy of the light will change
-The stain will transmit the light back at a lower wavelength appearing a different color
The longer the wavelength the _________ the intensity - Answer- lower
Blue light - - Answer- Orange filter
, Green light - - Answer- Red Filter
Purple light (UV) - - Answer- Yellow filter
What setting would you set the camera to when using ALS - Answer- ISO of 100-400,
f/8-f/11 and exposure set at -1 or -2, shutter speed 5-10 sec
UV light is in the range of _______ to ______ wavelength - Answer- 100nm to 400nm
UV light can also stimulate ___________ in the visible light range - Answer-
Fluorescence
Bloodstains will have similar patterns if they are caused by - Answer- Similar
occurrences
Blood drops are spherical during free fall because of - Answer- Surface tension
Blood will stay spherical until it is acted on by a force - Answer- true
Striking a smooth surface produces ________ satellite spatter - Answer- few
Striking a rough surface produces ________ satellite spatter - Answer- more
Force and spatter size are _________ related - Answer- inversely
Little force creates ______ spatter drops - Answer- big
Big force produces ________ spatter drops - Answer- little
Larger spatter drops have larger mass and can travel _____ than small spatter drops
with smaller mass - Answer- farther
Six general features of bloodstain patterns - Answer- -Direction of origination
-Angle of blood upon a surface
-Location/position of body during bleeding
-Movement of bleeding person
-Minimum number of blows administered
-Approx. location of person inflicting blows
3 types of blood stains - Answer- -Passive
-Transfer
-Impact
Passive Bloodstains - Answer- Patterns created from the force of gravity
Transfer Bloodstains - Answer- object comes into contact with bloodstains
SOLUTIONS
When a shirt partially reflects the color red, what does this mean? - Answer- That the
shirt is absorbing all other colors, but the red is being reflected
Light is transmitted through - Answer- -Glass, Water, or Liquids
-Handkerchief, Camera filters
Conversion of light is when - Answer- Light can be absorbed and transmitted at a
different wavelength (fluorescence)
Fluorescence means - Answer- from one state to another
Luminescence - Answer- -light emitted by means other than burning, such as chemical
or biochemical action or radiation (causes other than heat)
-Encompasses both fluorescence and phosphorescence
Fluorescence - Answer- A material that glows only while it is currently being stimulated
by a stronger light (ALS or FLS)
Phosphorescence - Answer- A material that contains some of the radiation they
absorbed from stimulating light and continues to glow after the light has ceased (Glow in
the dark toys)
Chemiluminescence - Answer- A material glowing because of a chemical reaction
(Luminol, glow sticks)
Using a stimulating light in the range of ________ - _______ nm such as an ALS is
helpful when searching for ________ ________ - Answer- 400-700nm
bodily fluids
How does the alternative light source work? - Answer- -The stain will absorb the light
-The initial energy of the light will change
-The stain will transmit the light back at a lower wavelength appearing a different color
The longer the wavelength the _________ the intensity - Answer- lower
Blue light - - Answer- Orange filter
, Green light - - Answer- Red Filter
Purple light (UV) - - Answer- Yellow filter
What setting would you set the camera to when using ALS - Answer- ISO of 100-400,
f/8-f/11 and exposure set at -1 or -2, shutter speed 5-10 sec
UV light is in the range of _______ to ______ wavelength - Answer- 100nm to 400nm
UV light can also stimulate ___________ in the visible light range - Answer-
Fluorescence
Bloodstains will have similar patterns if they are caused by - Answer- Similar
occurrences
Blood drops are spherical during free fall because of - Answer- Surface tension
Blood will stay spherical until it is acted on by a force - Answer- true
Striking a smooth surface produces ________ satellite spatter - Answer- few
Striking a rough surface produces ________ satellite spatter - Answer- more
Force and spatter size are _________ related - Answer- inversely
Little force creates ______ spatter drops - Answer- big
Big force produces ________ spatter drops - Answer- little
Larger spatter drops have larger mass and can travel _____ than small spatter drops
with smaller mass - Answer- farther
Six general features of bloodstain patterns - Answer- -Direction of origination
-Angle of blood upon a surface
-Location/position of body during bleeding
-Movement of bleeding person
-Minimum number of blows administered
-Approx. location of person inflicting blows
3 types of blood stains - Answer- -Passive
-Transfer
-Impact
Passive Bloodstains - Answer- Patterns created from the force of gravity
Transfer Bloodstains - Answer- object comes into contact with bloodstains
