Crime Scene Manual Flashcards
This technique is used to test stains for the presence of proteins found in blood.
Hemastix - Presumptive Test for Blood
When using Hemastix, a positive response indicates the suspected stain is ______________________________.
possibly comprised of or contains blood
Hemastix ____________________ distinguish human blood from the blood of animals.
cannot
False positive results are possible.
When using Hemastix _____________ results are possible.
“false positive”
Hemastix has a shelf life of ________________.
Approximately One year
While using Hemastix beyond the expiration date will not produce “______________” results, it may produce “______________” results.
will not produce “false positive” results
may produce “false negative” results
As a general practice, Hemastix should be __________ or used only for training beyond the date of expiration.
discarded
Before being used to perform test(s) upon questioned stains, the Hemastix reagent should be tested _______________________.
against a known human blood standard
A control test should be conducted whenever test strip(s) from a new container are used _______________________________ or if ______________________________________________.
for the first time or if more than 24 hours has elapsed since a control test was performed for a previously used container.
Testing with Hemastix will likely __________________ the appearance of the stain being tested.
change
A stain should be photographed prior to testing if its _______________ may be relevant to the investigation.
characteristics
Hemastix is very sensitive; therefore, it is only necessary to transfer _______ of the stain onto the swab.
a trace
When testing with Hemastix, a positive result is indicated by the immediate appearance of a __________ color on the pad.
blue-green
When using Hemastix, if the color change is _____________ (within 1-2 seconds), the result is negative.
not immediate
If a Hemastix test result is not “immediate” (1-2 seconds) then there is not a _______________.
positive result
The pale yellow pads at the ends of the strips ore impregnated with the chemical compound ___________________, which is a blood reagent commonly used in liquid form to perform presumptive tests at crime scenes.
tetramethylbenzadine
The chemical components of the Hemastix ________________ with DNA analysis.
do not interfere
The two techniques used to test stains for the presence of the acid phosphatase enzyme present in human semen utilized by the Texas Rangers are the _____ ______ _____ _______ and the _________ _________.
Peavy Seminal Fluid Dischap - Presumptive Test for Semen
and
Arrowhead Forensics
When using Peavy Seminal Fluid Dischap, a ________________ response indicated the probable presence of semen.
positive (purple color)
When using Peavy Seminal Fluid Dischap the color change should occur within a few seconds (__________), color change may not be immediate.
30 seconds
any color change after 30 seconds should be disregarded
When using Arrowhead Forensics, a ________________ response indicated the probable presence of semen.
deep purple
The acid phosphatase reagent ampoule _______________ be applied directly to the suspected semen stain.
should not be
The acid phosphatase testing will __________ change the appearance of the stain being tested.
likely
When using either the Peavy Seminal Fluid Dischap or the Arrowhead Forensics, a stain should be _____________ prior to testing if its characteristics may be relevant to the investigation.
photographed
The ____________________ or _______ test is the test utilized in the DPS Crime Laboratory for the detection of semen.
acid phosphatase or “AP”
Since the acid phosphatase enzyme is present in ___________, ________________ need not be present for a positive reaction.
semen
spermatozoa
This chemical reagent is used to locate latent traces of blood on both porous and non-porous surfaces.
Bluestar
Bluestar should be used in a ____ room.
darkened
When using Bluestar outdoors, ______________.
wait for night
Bluestar should be used to _______________ and ______________ post-offense cleaning of a bloodstained area rather than as purely a presumptive test.
demonstrate and photograph
When spraying Bluestar, apply a _________ of the mixture from a distance of about two feet.
fine mist
_____________ Bluestar will not increase the effectiveness of the mixture.
Over-spraying
To photograph a luminescent response with Bluestar, one should use ____ ________ ____ ________ photography.
Bulb Extended Time
When using Bluestar a _______________ response is presumptive positive for the presence of blood.
luminescent
The use of Bluestar _________________ the testing of evidence for DNA.
will not prohibit
Bluestar has a shelf life of _____ years.
three
Once Bluestar is mixed, it is best used within _____ of production.
three hours
Bluestar __________ be stored after production.
should not
Packaging of bloodstained clothing should be done in order to __________________________________.
to avoid or prevent transfer or alteration
Bloody clothing may be placed on a sterile clothes hanger and _______ __ _____ with all seams taped.
wrapped in paper
If blood soaks through a packaged item of evidence you should__________________________?
not unpackage the item
Remove the evidence tag, repackage the item, then place the evidence tag on the outside of the new paper.
The technique used to collect a portion of a visible biological stain (blood, semen, saliva, etc.) for subsequent crime laboratory DNA analysis:
Discriminate collection of a biological stain.
The technique used to collect a portion of a visible biological stain (blood, semen, saliva, etc) for subsequent crime laboratory (DNA) analysis is:
dampen an individually packaged sterile swab with sterile water, then vigorously scour the portion of the stain to be collected.
Return the swab to its wrapper with the swab end near the opening.
When swabbing a biological stain, one should attempt to obtain a _____________ of the biological material on one portion of the swab rather than allowing _________ of the stain throughout the swab.
concentration / diffusion
The technique used to attempt to collect latent traces of biological material (blood, semen, saliva, etc.) from surfaces upon which its existence is suspected but not apparent or visible.
Indiscriminate collection of biological material.
Collection method the same as discriminate collection.
For pourus surfaces with visible blood stains, it is always best to ___ _ ______ containing the stain when it is not practical or possible to collect the entire item.
cut a swatch
This technique is used to enhance faint pattern transfers in blood on absorbent surfaces.
Tri-Dri Leucocrystal Violet
Leuccrystal Violet (LCV) can create _______________ when applied to bloody pattern transfers which can cause degradation of pattern detail, especially in friction ridges.
bubbles
LCV is preferred for ______________________________ (e.g., carpeting, clothing, paper, etc.).
porous or absorbent surfaces
LCV produces a _____________________ colored reaction when it comes into contact with blood. The background surface color should be considered when deciding to whether to apply LCV.
violet or purple
LCV has a __________________ shelf life. Once mixed, the LCV solution has a ____________ shelf life.
indefinite
30 day
A Tri-Dri Lecocrystal Violet Kit is mixed with one _____ ______ __ ________ ________.
one 16 oz. bottle of hydrogen peroxide
All bloodstains must be _______________ prior to the application of LCV or Amido Black.
dried
Cyanoacrylate fuming may be __________________ to the LCV and the Amido Black process.
detrimental
The ______ detail can normally be achieved by applying the LCV to the faintest patterns.
finest
When applying LCV for footwear patterns, spraying ___________ the last visible pattern will normally produce the best results.
just beyond
If the pattern is comprised of blood, the LCV solution will react within __________ by changing the stain a violet color.
30 seconds
This technique is used to enhance faint pattern transfers in blood on non-porous surfaces.
Amido Black
Amido Black is preferred over Leucocrystal Violet for the ___________ and ___________ of bloody friction ridge detail.
enhancement and development
Caution must be exercised when applying the methanol-based formula to ___________________ surfaces because it may destroy friction ridges and/or other pattern transfers as well as the surface beneath them.
painted or lacquered
Amido Black should not be applied to ______ ________ because it may stain the surface and prevent visualization of any enhanced bloodstain patterns.
porous surfaces
_________________ is preferred over _________________ for the enhancement and development of bloody friction ridges.
Amido Black preferred over Leucocrystal Violet
Amido Black produces a ______ or ____ ____ stain when it comes into contact with blood.
indigo or dark blue
Amido Black has two forms of solutions, ______________ and ___________.
methanol based and water based
Amido Black has an __________ shelf life.
indefinite
Amido Black should be stored at ________________.
room temperature
Amido Black __________ be stored in vehicles for extended periods.
should not
The Amido Black water-based formula is _______ in sensitivity and color intensity to that of the methanol-based formula.
similar
If both LCV and Amido Black are contemplated, ___________ must be sequenced first.
LCV
When using the methanol based Amido Black solution leave the developer solution on the surface for approximately __________ to ________.
30 seconds to 1 minute
When using the water based Amido Black solution leave the developer solution on the surface for approximately __________ to ________.
3 to 5 minutes
A small fan or pressurized air canister may be used to ______ the solutions away from the developed patter.
“push”
Once a pattern has been enhanced with Amido Black, it may then be photographed using ______________________.
Comparison Photography
When burning photos taken with the Nikon D7100 / D7000 camera to a disk, two DVD-R should be created. The first DVD-R created will be labeled ___________________ and should be handled as a piece of evidence. The second DVD-R will be labeled _______________ and should be kept in the investigative file.
1st disk - “Original/Archive Disk”
2nd disk - “Working Disk”
This technique is used to photograph subjects under reduced or limited lighting conditions whenever an exposure under existing light is preferred over the use of the flash and when the proper exposure can only be achieved with a shutter speed that renders hand-held operation of the camera impractical due to camera movement.
Metered Extended Time Exposure
The Metered Extended Time Exposure technique involves slower shutter speeds that make camera movement and subject movement a paramount concern, the camera and subject should be rendered ____________ during the exposure period. The remote shutter release cable or time delay function must be used. Using hands/fingers to activate the shutter release usually results in a blurred image.
immobile
This technique is preferred for exposures made under lighting conditions that are too dark for metering or when the desired exposure time exceeds 30 seconds.
Bulb Extended Time Exposure
The Bulb Extended Time Exposure technique involves exposure times in excess of 30 seconds; therefore, the camera must be immobilized on a tripod or other similar device during exposure periods. _________ operation is not an option.
Hand-held
These procedures are used to obtain macro photographs of items of evidence that are to be used for comparison with known standards.
Comparison Photography
Due to the shallow depth of field associated with macro photography, use the tripod and remote shutter release cable (or time delay shutter release function) to immobilize the camera to prevent ________ of fine details.
blurring
The objective of comparison photography is to utilize _____ and/or _______ to obtain a sharp image with the greatest possible contrast between the subject and surrounding surfaces.
light and/or shadows
Oblique or angled lighting is often employed when using comparison photography to produce ____________ in order to achieve this effect, especially when photographing impressions, tool marks, engravings, etc.
fine shadows
This technique is used to obtain photographs of luminescent chemical reactions associated with reagents such as luminol and BlueStar.
Luminescent Reagent Photography
Due to the __________ nature of luminescent chemical reactions, the “faster” 50mm w/f1.8 aperture lens may be the preferred lens to use for this technique.
transient
This technique is used to obtain illuminated images of extremely dark areas that, due to their size, cannot be effectively illuminated with a single function of the flash.
Painting with Light
This technique is used to obtain images of laser beams to illustrate bullet path(s) convergence/origin point(s) for bloodstain patterns, and/or any circumstance where photography of a laser beam is desirable.
Photography of Laser Beam
This technique is used to photograph subjects under reduced or limited lighting conditions whenever the introduction of artificial light from the flash unit is preferred over existing light.
General Flash Photography
This technique is used to photograph subject areas by introducing artificial (flash) onto a dark foreground while using metered time exposure to properly expose lighted background areas. It is referred to __________________ because the flash is activated when the shutter is first opened (typical) or just before the shutter is closed during the exposure interval. This technique is most effective in large areas (usually at night) where the lighted background is too far away to be influenced by the flash.
Curtain Flash Photography
This technique is used to photograph subjects that fluoresce when illuminated with a forensic light source (e.g. dry semen stains, florescent fingerprint powders, certain fibers, etc.).
Fluorescent Photography
Fluorescent Photography technique involves slower shutter speeds that make camera movement and subject movement a paramount concern, the camera and subject should be rendered ____________ during the exposure period. The remote shutter release cable or time delay function must be used. Using hands/fingers to activate the shutter release usually results in a blurred image.
immobile
When using Fluorescent Photography, a forensic light source is used to illuminate the subject at a particular _________ so that the fluorescent response may be visualized and photographed.
bandwidth
TrackStone casting compound is used to create ___________________ casts of impression evidence such as footwear and tire tread impressions found in materials such as dirt, mud, etc.
three-dimensional
Trackstone casting compound is a __________________ that hardens when exposed to humidity.
very fine powder
TrackStone begins to set __ _____ as it is mixed with water.
as soon
TrackStone should be applied to the impression as soon as the ________ ___________ is achieved.
desired consistency
Efforts to obtain casts of impression evidence are not always successful; therefore, _____________________ should be made of any impressions before casting is attempted.
photographs
Loose debris that has obviously accumulated in the impression since it was formed can be _______________________.
removed with tweezers
Debris which is ____________________ in the impression should be left in place.
imbedded
Impressions found in loose aggregate (e.g., sand) should be set with an ______________ fixative prior to casting.
aerosol spray
If necessary or desirable, place the _______________ around the impression to contain the casting compound, especially on sloped surfaces.
casting frame
Never _______________ the compound into the impression.
simply pour
Pour the Trackstone compound from a height near the surface onto an area ____________ the edge of the impression so that the compound will spill over the edge and slowly fill the impression.
just outside
Use a _______ to interrupt the fall of the Trackstone compound and direct the flow of the compound into the impression.
baffle (e.g., stir stick, piece of cardboard)
When using Trackstone to cast impressions in snow, __________ should be substituted for some of the water to create slush.
snow
When casting impressions completely submerged in water, the impression should be isolated with a casting frame or other form so that the frame or form is above water level.
True
Dry TrackStone powder should be added to the submerged impression until the water is displaced and the desired consistency is achieved.
True
In wet conditions TrackStone should be allowed to dry for ________.
one hour
A good rule of thumb for allowing the Trackstone cast to set is _____________________.
20 to 30 minutes
The Trackstone cast will set _______ in hot weather and ___________ in cold weather.
faster in hot weather and take longer in cold weather
Thick mixtures of Trackstone set ________ while thin mixtures __________.
quicker
take longer
The top of the Trackstone cast should be appropriately marked with a permanent marker immediately after the curing process with at a minimum of _____, ______, __________, and _____________. It should also be marked with an arrow indicating north.
time, date, evidence number, and investigators initials
Any casting compound similar to TrackStone such as _________________ may be used to obtain casts of impression evidence. However, _________________ is not recommended.
dental stone
Plaster of Paris
Adhesive materials (wide fingerprint tape, contact paper, etc) are used to lift larger pattern transfers (e.g., _______________, ________________________, etc.) that have been developed with fingerprint powder on relatively smooth surfaces.
footwear patterns, plantar friction ridge detail
Powder development is most effective for patterns that contain __________________ or ______________________.
oily materials or moisture
Powder development ____________ normally be used to collect pattern transfers in dust.
should not
Black gelatin lifter should be used for ________ __ ____.
patterns in dust
________________________ are used to lift pattern transfers (especially footwear patterns) that have been deposited in dust or developed with fingerprint powder.
Gelatin lifters
Generally, _____________________ colored gelatin lifters are used to lift patterns developed with fingerprint powder while _____________ colored gelatin lifters are used to lift those found in dust.
white colored for fingerprint powder
black colored for dust
Since a larger lifting medium is being used to lift footwear patterns, plantar friction ridge detail, etc., extra care must be employed to prevent the development of ______________ between the lifting medium and the surface.
air pockets
In some cases, it may be desirable to create a ______________ in air pockets that do develop so as to insure the adhesive makes contact with all detail in the pattern.
pin hole
Gelatin lifters are subject to degradation from ____________________.
high temperatures and humidity
Gelatin lifters may be routinely carried in the trunks of automobiles but should not be normally carried in the _____________________, especially during summer months.
passenger compartments
Gelatin lifters may be routinely carried in the trunks of automobiles but should not be normally carried in the _____________________, especially during summer months.
passenger compartments
To prevent the effects of humidity, the _________________ packaging should not be opened until the lifters are to be used.
foil packaging
Photographs made of patterns lifted with gelatin lifters are the ___________________ of the patterns as they were on the original surface. When such an image is submitted to the crime laboratory, this condition should be noted so that the image may be reversed when the final image is rendered for comparison analysis.
reverse image
_______________ is used to make high resolution casts of various types of pattern transfer and impression evidence.
Mikrosil
Mikrosil can be used to make high resolution casts of such evidence as ______________, ____________, and other ____________________.
tool marks
firearms marks
other small impressions
Mikrosil is also effective in lifting fingerprints developed with powder from ___________ or _____________ surfaces.
rough
textured
Mikrosil begins to set as soon as ______________ are mixed. Therefore, it should be applied to the impression or surface immediately thereafter.
the components
Mikrosil is available in four (4) colors: ______________________. Each color provides unique contrast for various applications.
white, gray, black, and brown
White and black Mikrosil are preferred for lifting developed fingerprints from __________________________.
irregular surfaces
Brown and gray Mikrosil are preferred by ________________ and _________________ examiners for the contrast provided for microscopic comparison examinations.
tool mark and firearms examiners
A Mikrosil Kit consists of ___________ separate compounds that must be mixed prior to use.
two
Tube of Mikrosil
Tube of hardener
The two tubes of Mikrosil should be blended together for _______ seconds.
30 to 60
The Mikrosil compound needs to set for ____ to _____ minutes in if the temperature is above 68 degrees. The material will need to set for ________ longer in colder temperatures or thick applications.
five to eight minutes
fifteen minutes
____________________ or _____________________ can be used to develop sebaceous (oily) latent friction ridges on various surfaces.
Standard fingerprint powder or magnetic fingerprint powder
Powder development is an instinctive process; however, care must be taken to avoid _______________ and/or ___________ of the ridge detail.
overdevelopment and/or destruction
If possible, prints should be ___________ throughout the development process and prior to any attempt to lift them.
photographed using comparison photography
Silver/grey powder may be used on __________________ surfaces. However, plain black powder is preferred.
dull black
Florescent powder development may be preferable for ________________________ surfaces.
multi-colored
Fluorescent powder should be used _______________ than standard fingerprint powder.
more sparingly
A _____________________ must be used in concert with the development process of fluorescent powder to insure proper development.
forensic light source
If practical, the object containing the latent prints should be treated with ________________________ prior to powder development.
cyanoacrylate (Super Glue)
Trace elements that have been visually identified are collected discriminately using a ____________, ______________, ______________, or ________________.
gloved hand, sterile tweezers, adhesives, or other methods
If it is necessary to test a suspected bullet defect in an immovable object for the presence of both lead and copper, the _______________ test must be sequenced first.
copper
__________________________ are utilized to indiscriminately process the hands of persons suspected to have fired, handled, or been in proximity to a firearm when it was discharged.
Adhesive stub type gunshot residue (GSR) evidence collection kits
Laboratory examinations of the stub type GSR kits are conducted using the __________________________ or ___________________________.
scanning electron microscope (SEM)
or
Energy Dispersive Spectrometer (EDS)
GSR stub lifts collected more than ______________ following the event will not normally be analyzed by crime laboratory examiners.
4 hours
GSR stub lifts collected from gunshot victims (including suspected suicide victims) will _______________ be analyzed by crime laboratory examiners.
not normally
The 2-stub kit may be submitted to the DPS Crime Laboratory.
True
There is no practical concern that the use of a 2-stub kit would cause a stub to become “__________” before GSR particles could be collected.
overloaded
The DPS Crime Laboratory will not report conclusions as to where on the hand the GSR was detected (back or palm).
True
An __________________ is utilized to collect gunshot residue from immovable objects/surfaces.
acetic acid solution
________________________ is utilized to determine and demonstrate bullet flight paths for shooting scene reconstruction.
Laser trajectory kit
Bodily fluids (especially dry semen stains) are known to emit a fluorescent response when “_____________” with UV, violet, or blue wavelengths.
excited
____________ and other types of _______________ may also have fluorescent properties when excited with various wavelengths and viewed through the appropriate barrier filter.
Fibers and other types of trace evidence
Typically, prints are _____________ with fingerprint tape and placed onto a backing card after they have been developed and photographed.
lifted
This technique is used to develop and preserve latent friction ridge detail on non-porous items that are small enough to be placed into a fuming chamber using the HotShot.
Chambered Cyanoacrylate Fuming
Ideally, fuming should be accomplished before ______________ to stabilize and preserve the prints.
packaging
______________ are applied to develop latent fingerprints primarily on porous surfaces.
Iodine fumes
Iodine fumes are absorbed by _________________ residue in latent fingerprints to render the prints visible.
fatty or oily
Iodine fuming __________________ interfere with any other fingerprint processing technique.
will not
____________________ is primarily used to develop latent prints on multicolored surfaces for visualization and photography with a forensic light source.
Fluorescent fingerprint powder
Magnetic fingerprint powder is used to develop ________________ latent friction ridges on various surfaces. Typically, prints are lifted with fingerprint tape and placed onto a backing card after they have been developed and photographed.
sebaceous (oily)
Chemical enhancement techniques (i.e., Leucrocrystal Violet and/or Amido Black) are used to develop _________________ evidence deposited in blood.
latent friction ridge
Prior to using any indiscriminate process for collecting trace evidence, suspected surfaces should be carefully examined with both _____________ and a _______________ in an effort to visually locate trace elements.
white light and forensic light source
Trace items discovered by using a white light or a forensic light source should be photographed using the ______________________.
comparison photography method
Trace elements may be easily lost if not __________________.
carefully handled
The method of collection must be tailored to the ____________ of evidence being collected.
type and size
Some trace items may be very easily collected with a ______________ or _________________ while others may require a small piece of tape or other adhesive to securely collect.
gloved hand or sterile tweezers
Mikrosil casting material is used to make _________________ casts of bullet defects.
high resolution
To cast bullet defects, tool mark, or other impressions, use _____________ colored Mikrosil.
gray or brown
_________________ are preferred to by tool mark and firearms examiners for the contrast provided for microscopic comparison examinations.
Gray and brown
A chemical reagent ________________ is utilized to test a suspected bullet defect in an immovable object for the presence of copper.
rubeanic acid
If test for both lead and copper are contemplated, the _____________ copper test must be sequenced first.
copper
To prevent contamination of the chemicals when testing for copper, do not allow the ________ to come into contact with the swab.
dropper
Before being used to test a suspected bullet defect, a control test should be performed upon a known standard containing copper (e.g., _________________________________.
a piece of copper wire or a penny
The rubeanic acid reagent also reacts positively to ______ and ______.
nickel and cobalt
A small glass dropper bottle containing ______________________________ and a small glass dropper bottle containing ___________________ of rubeanic acid solution.
12% ammonium hydroxide solution
1% ethanol solution
A presumptive positive test result for the presence of copper is indicated by an immediate ___________ colored reaction.
green-black
The field test for copper should only be used to field test _________________.
immovable objects
Whenever possible the actual suspected bullet defect should be _______ and submitted for crime laboratory analysis.
excised
A chemical reagent (Sodium Rhodizonate) is utilized to test suspected bullet defects in ____________________ for the presence of lead.
immovable objects
Before being used to test a suspected bullet defect, a positive control test should be performed upon a known standard containing lead (e.g., _____________________________).
a bullet, a lead fishing weight, etc.
The sodium rhodizonate solution used to test a bullet defect for the presence of lead has a very short shelf life (_____). Therefore, it must be used at the scene.
1 day
The sodium rohodizonate solution also reacts positively to other heavy metals (e.g., ______, etc.).
Barium, Strontium, Etc.
A small glass dropper bottle containing pre-mixed solution of ______________ and sodium rhodizonate powder are needed to test for the presence of lead.
15% acetic acid
The presumptive positive result for the presence of lead is indicated by a __________ color reaction.
red-violet
