Interview Flashcards
If I was not ready, I would not have the opportunity <3
1
Q
what is a friction ridge impression?
A
any impressions made by the raised portion of the epidermis on the palmar (hand) or plantar (foot) skin
2
Q
what is sequential processing?
A
using a series of development techniques in a specific order to maximize the development of friction ridge detail
3
Q
what are some things that can help determine what technique to use?
i.e. choosing a certain technique would depend on….
A
– surface composition (porous/non-porous)
– composition of the impression medium
– condition of the surface
– presence of contaminants
– detrimental effects of the procedure on the surface
4
Q
in general, what is the 1st step in sequential processing, no matter the surface? what is the purpose?
A
visually examine the item
– are there any visible (patent) or plastic (three-dimensional) impressions?
– ID the factors that determine the proper techniques and sequence to apply them
5
Q
in general, what is the 2nd step in sequential processing? what is the purpose?
A
examine the item under a laser or forensic light source to detect:
– latent impressions with properties of luminescence without any chemical treatment
– the fluorescent properties of the item itself
6
Q
what is a porous surface? list some examples
A
surfaces that are absorbent (untreated paper, cardboard, raw wood)
7
Q
list the sequential process steps for porous surfaces
A
– visual exam
– (maybe) check for inherent luminescence
– apply techniques/reagents
– apply dry heat or humidity if required by technique
– examine with laser if needed
– analyze and document any developed impressions
8
Q
what kind of surface would you use DFO on? what physical form is it? how does it work?
A
porous surfaces; a liquid solution; it reacts with amino acids to produce friction ridge detail with fluorescent properties
9
Q
what kind of surface would you use 1,2-Indanedione (IND) on? what physical form is it? how does it work?
A
porous surfaces; a liquid solution; it reacts with amino acids present in print residue to produce a fluorescent product
10
Q
what kind of surface would you use ninhydrin on? what physical form is it? how does it work?
A
porous surfaces; a liquid solution; reacts with amino acids to produce friction ridge detail purple in color
11
Q
what are the different kinds of ninhydrin solutions, and what surfaces are they used for?
A
– ninhydrin in acetone: most porous surfaces except those with soluble inks or paint
– ninhydrin in hexane: better for porous surfaces with inks/paint, good for cardboard
– ninhydrin HT: used on thermal paper
12
Q
what kind of surface would you use physical developer on? what physical form is it? how does it work?
A
porous surfaces that have been wet; a liquid solution; it’s a silver physical development process which reacts with some components of friction ridge secretions, as well as fatty or oily contaminants (forms a silver-gray deposit)
*amino acids are water soluble, which is why DFO/indanedione/ninhydin probably won’t work on porous surfaces that have been wet
13
Q
what is a non-porous surface? list some examples
A
surfaces that are not absorbent (glass, metal, plastic)
14
Q
list the sequential process steps for non-porous surfaces
A
– visual exam
– (maybe) check for inherent luminescence
– cyanoacrylate ester fuming
– apply fluorescent dye stain
– laser or ALS
– apply fingerprint powder
– analyze and document any developed impressions
15
Q
what kind of surface would you use cyanoacrylate ester on? what physical form is it? how does it work?
A
non-porous surfaces; liquid glue into fumes; cyanoacrylate ester (Superglue) is heated to create fumes that develop friction ridge detail, it reacts with the proteins to produce a white impression
16
Q
what kind of surface would you use fluorescent dye staining on? what physical form is it? how does it work?
A
non-porous surfaces, specifically those already treated with cyanoacrylate ester; liquid solutions; it’s used to help visualize cyanoacrylate-formed friction ridge detail
17
Q
what are three types of fluorescent dyes used to stain cyanoacrylate-formed impressions?
A
rhodamine 6G (R6G), MBD, and ardrox
18
Q
what kind of surface would you use fingerprint powders on? how does it work?
A
non-porous surfaces; the powder sticks to the moisture and oil in a fingerprint to help visualize the impression
19
Q
what are some types of fingerprint powder?
A
– magnetic
– non-magnetic
– fluorescent
– bichromatic
– various monochromatic types
20
Q
what is considered a special surface or special condition (not strictly porous or non-porous)?
(there are 6)
A
– semi-porous surfaces (glossy coated paper)
– items comprised of both porous and non-porous surfaces (glass or plastic bottles with paper labels)
– items that are or have been wet
– latent impressions that were deposited in blood
– surfaces contaminated with food
– adhesive surfaces
21
Q
how would you process a semi-porous surface, or a surface comprised of both porous and non-porous surfaces?
A
apply the sequence for non-porous surfaces first, then apply the sequence for porous surfaces
22
Q
how would you process a non-porous surface that is or has been wet?
A
allow the surface to dry and then apply sequence for non-porous surfaces
23
Q
how would you process a porous surface that is or has been wet?
A
apply physical developer
24
Q
how would you process an impression deposited in blood?
A
– on a porous or semi-porous surface, apply leuco-crystal violet or ninhydrin
– on a non-porous surface, apply amido black or leuco-crystal violet
25
how would you process a surface contaminated with food?
apply sudan black OR cyanoacrylate fume the item, then apply sudan black
26
general overview, how would you process items with adhesive surfaces?
-- process the non-adhesive side first
-- then process the adhesive side
-- after processing the adhesive side, go back and process the non-adhesive side with dye stain and powder, if applicable
27
how would you process the non-adhesive side of an item?
-- if the non-adhesive side is porous, apply the appropriate technique for porous surfaces
-- if the non-adhesive side is non-porous, cyanoacrylate fume the item while protecting the adhesive side
28
how would you process the adhesive side of an item?
apply one of the following:
-- crystal violet
-- Liqui-Nox/black powder
-- wetwop
29
what is UN-DU?
a product that temporarily neutralizes adhesives; used if the adhesive needs to be removed from a surface
30
what kind of surface would you use amido black on? what physical form is it? how does it work?
a non-porous surface with an impression deposited in blood; a liquid solution; it stains the proteins in blood a blue-black color (also can stain the object, which is why it's not ideal for porous surfaces)
31
what kind of surface would you use leuco-crystal violet (LCV) on? what physical form is it? how does it work?
either porous or non-porous surfaces with impressions left in blood; a liquid solution; it stains blood violet and fluoresces
32
what kind of surface would you use sudan black on? what physical form is it? how does it work?
surfaces contaminated with food; a liquid solution; it is a black dye that stains fats, oils, sebaceous components, and contaminants of friction ridge residue (blue-black color change)
33
what kind of surface would you use crystal violet on? what physical form is it? how does it work?
the adhesive side of an item; a liquid solution; a violet stain used to develop or enhance friction ridge detail, viewed by either fluorescence or non fluorescence (violet color change)
34
what kind of surface would you use Liqui-Nox/black powder on? what physical form is it? how does it work?
the adhesive side of an item; a liquid solution; a solution of detergent and black powder used to develop friction ridge detail on tape (black or gray deposit)
35
what kind of surface would you use wetwop on? how does it work?
the adhesive side of an item; a liquid solution; a premixed commercially prepared product used to develop friction ridge detail on tapes, comes in black and white
36
what are the possible results at the end of processing the item?
results will be one of the following:
-- suitable for comparison
-- not suitable for comparison
-- no latent impressions developed
37
friction ridge examinations are conducted by the application of what scientific method?
the analysis, comparison, evaluation, and verification method (ACE-V)
-- not strictly linear
-- can return to any previous phase throughout the exam
38
how many levels of friction ridge impression detail are there?
3
39
what are level 1 impression details?
origin and orientation indicators, such as the overall shape of the impression, ridge flow and pattern types, or focal points (delta, core, etc)
40
what are level 2 impression details?
individual friction ridge paths, friction ridge events, and their relative arrangements (bifurcations, ending ridges, dots, continuous ridges)
41
what are level 3 impression details?
ridge structures and their relative arrangements (edge shapes, pores)
42
what are some features that might be reflected in all 3 levels of impression details?
creases, scars, warts, incipient ridges
43
define the A in ACE-V
analysis: the assessment of an impression to determine its value or suitability for comparison
44
during analysis in ACE-V, what determines the suitability of an impression for comparison?
determination of suitability based on assessment of:
-- the quality of features (clarity of observed features)
-- the quantity of features (amount of features and area)
-- the specificity of features (weighted values and rarity)
45
during analysis in ACE-V, how is an impression's suitability for comparison expressed?
described as a quality rating, high (HQR) to low (LQR)
46
define the C in ACE-V
comparison: the side-by-side observation of all levels of details to determine whether the two impressions are in agreement or disagreement
47
what is the comparison in ACE-V based on?
| whether two impressions agree or disagree is based on....
based on features, sequences, and spatial relationships within the tolerances of clarity and distortion
48
during comparison in ACE-V, how does tolerance apply?
comparative measurement tolerance must be considered during comparison phase
-- more distortion in print = more tolerance for variations between them = requires more details when making an agreement/disagreement determination
49
define the E in ACE-V
evaluation: exam progresses from comparison into evaluation phase when sufficient information is obtained to form a conclusion
50
during evaluation in ACE-V, what are the possible conclusions?
-- identification
-- exclusion
-- inconclusive
51
during evaluation in ACE-V, what does an "identification" conclusion mean?
sufficient features are in agreement to conclude that two areas of friction ridge impressions originated from the same source
*at BFS, identification needs at least 8 second level characteristics in agreement based on features, sequence, and spatial relationship
52
during evaluation in ACE-V, what does an "exclusion" conclusion mean?
sufficient features are in disagreement to conclude that two areas of friction ridge impressions are not from the same source
53
during evaluation in ACE-V, what does an "inconclusive" conclusion mean?
neither an identification nor an exclusion can be reached
54
define the V in ACE-V
verification: a subsequent examiner independently applies the ACE process to either support or refute the conclusions of the original examiner
55
what are the two kinds of verification in ACE-V?
-- sometimes it is a peer review of all analyses and comparisons performed, and conclusions formulated
-- sometimes is a completely blind verification
56
what are some automated searches used for fingerprint impressions?
-- DOJ automated latent print system (ALPS)
-- FBI next generation identification (NGI)
-- western identification network (WIN)
-- county database in which the crime occurred
57
what is the super basic history of fingerprints? i.e. where was it first seen? what were they used for?
-- first known culture to use f/p is China, later seen in Japan and India
-- first used in clay seals on scrolls, then later to sign documents on paper
58
list some possible criminal or civil applications for fingerprints as an identification method
-- to identify immigrants
-- employment records (hiring/firing)
-- on legal documents to prevent fraud
-- identifying individuals present at a crime scene, suspect or not
-- criminal records for law enforcement
-- identifying disaster victims
59
what are the layers of the skin on your fingers?
epidermis, dermis, and hypodermis
60
what are primary and secondary ridges?
the ridges and furrows on the surface of friction ridge skin are firmly rooted in the dermis by:
-- primary ridges = under the surface ridges
-- secondary ridges = under the valleys
61
why are fingerprints so easy to leave behind?
| biologically speaking
the sweat glands on hands/feet are large, more active, and denser than in any other area of skin on the body
62
what does it mean that friction ridge skin "persists"?
-- as cells slough off and new ones take their place, they replace in concert
-- this means the 3-D morphology of the surface ridges is maintained, and the friction ridge skin "persists"
-- as you age, the arrangement of the friction ridges doesn't change; the ridges and furrows maintain their position
63
advancing age has what effects on friction ridge skin?
-- surface ridges tend to flatten, making them appear less "sharp"
-- loss of elasticity in the dermis causes skin to become flaccid and to wrinkle
64
what is the foundation for friction ridge examinations as a means of identification?
| what is the discipline based on?
the ACE-V methodology, combined with philosophy of quantitative-qualitative examinations, provide the framework for practical applications of the friction ridge examination discipline
65
what fundamental principle allows for conclusive determinations?
| how do we know fingerprints work as an identification method?
because the source of the impression, friction ridge skin, is UNIQUE and PERSISTENT
66
when do friction ridges form during development?
-- begin to form appx. 10 weeks/3rd month/end of 1st trimester
-- grow until appx. 16 weeks, when the minutiae become set
67
how are minutiae formed during development?
-- exact mechanism for formation is unclear; may be mechanical or static; fusion or chemical
-- the exact location of any particular bifurcation or ridge ending within the developing ridge field is governed by a random series of infinitely interdependent forces acting across that particular area of skin at that moment
-- slight differences in the mechanical stress, physiological environment, or variation in the timing of development could affect the location of minutiae in that area of skin
68
what do volar pads have to do with friction ridge detail?
the shape of the volar pad during development influences the stress across the skin that directs ridge alignment
69
how does the symmetry of the volar pads affect friction ridge detail?
if the volar pad and other elements of finger growth are symmetrical during onset of primary ridge formation:
--a symmetrical pattern will result (whorl or arch)
if the volar pad is asymmetrical during development:
-- the same degree of asymmetry will be reflected in the ridge flow of the resulting pattern (loops)
70
does the size of the volar pad affect friction ridge detail?
yes, the size of the volar pad affects ridge count
-- large/high volar pad = high-count pattern
-- small/absent volar pad = low-count pattern
71
does genetics play any role in ridge detail?
-- genetics has been shown to play a role in pattern formation, but
-- the arrangement of minutiae within the pattern is a product of the unique developmental noise that occurs in that area of skin during friction ridge formation
72
what are some names for recording prints from known sources?
inked prints, record prints, standards, exemplars
73
what are major case prints?
-- a recording of all the friction ridge detail covering the hands (fingertips, sides, palm, etc)
-- aka major criminal prints, aka complete friction ridge exemplars
74
who was Bertillon? what did he do?
-- Alphonse Berillon
-- devised a complete system of identification, anthropometry, based on the measurement of specific body parts
-- became the first scientific system used to identify criminals
75
who was Faulds? what did he do?
-- Henry Faulds
-- determined that fingerprints are both individual and permanent
-- developed a syllabic system for classifying prints
76
who was Galton? what did he do?
-- Francis Galton
-- established that fingerprints are both permanent and unique
-- was the first to define and name specific print minutiae, called "Galton details"
-- developed a classification system based on assigning letters to the patterns (L = loop, W = whorl, A = arch)
77
who was Henry? what did he do?
-- Edward Henry
-- formulated a mathematical method of dividing f/p records into a large number of primary groupings that were based on Galton's pattern types
78
what is the Henry method/Henry classification?
-- an alpha-numeric system of f/p classification named after Sir Edward Richard Henry used for filing, searching, and retrieving ten print records
-- basically, assign a numerical value to each finger based on pattern, then values are added together and expressed as a ratio of even fingers over odd
-- next to the primary is the secondary, either capital or lower letters representing patterns
-- then the sub secondary, representing the ridge counts
-- this system allows for around 1000 primary groupings
79
what is the NCIC? how does it work?
-- National Crime Information Center
-- states are connected to the FBI's central computer, where agencies can search the databases
-- consists of a 20-character code representing all fingers and their patterns
80
what is AFIS? how does it work?
-- Automated Fingerprint Identification System
-- based on computerized extraction of minutiae
-- creates a mathematical map of the impression that can be compared to others by an algorithm
81
what is a latent print?
-- a transferred impression of friction ridge detail not readily visible
-- generic term used for unintentionally deposited friction ridge detail
82
what is a patent print?
readily visible prints from colored, transferrable media (ink, paint, blood, etc)
83
what is a plastic print?
three-dimensional impressions made by pressing fingers into fresh paint, wax, soap, tar, etc.
84
what is a QAP?
-- quality assurance program
-- the first step in adopting international standards through an accreditation program from a certified accrediting body that includes an external assessment
85
what does a QAP do?
| generally, not specific things
-- monitors and evaluates activities to ensure standards of quality are being met
-- writes and periodically reviews policies and procedures
-- addresses quality management, non-conforming work, quality review, and corrective actions
86
what are specific things our QAP does to ensure an analyst's work is up to required standards?
| what do we do to guarantee a high quality product?
-- establish/maintain a training program
-- ensure competency before independent casework
-- maintain proficiency testing
-- retain documentation of: quality assurance, evidence handling, examinations, conclusions, non-conforming work, corrective actions, and preventative actions
-- establish administrative and technical case review
-- require periodic audits, both internal and external
87
what do the federal rules of evidence (FRE 702) state in regards to testimony by experts?
if scientific, technical, or specialized knowledge will assist the trier of fact (jury) in understanding and making a determination, a witness qualified as an expert by knowledge, skill, experience, training, or education may testify if:
-- the testimony is based on sufficient facts/data
-- the testimony is the product of reliable principles and methods
-- the witness has applied the principles and methods reliably to the facts of the case
88
what is the Frye standard?
-- Frye v. United States
-- used to determine the admissibility of an expert's scientific testimony and other types of evidence
-- an expert opinion is admissible if the scientific technique on which the opinion is based is "generally accepted" a reliable in the relevant scientific community
89
what is the Daubert standard?
-- Daubert v. Merrell Dow Pharmaceuticals
-- if a litigant challenges the admissibility of scientific evidence, if is the function of the trial court/judge to act as a gatekeeper to determine whether the proffered opinion evidence is "relevant" and "reliable"
90
what are the 5 factors/criteria for the Daubert standard?
-- whether the technique/theory can be or has been tested
-- whether the technique/theory has been subject to peer review and publication
-- the known or potential rate of error
-- the existence and maintenance of standards or controls
-- the degree to which the theory/technique has been generally accepted in the scientific community
91
practice question, answer in layman's terms, as if describing to a jury: what is a latent print?
tbd
92
practice question, answer in layman's terms, as if describing to a jury: what is a known print?
tbd
93
practice question, answer in layman's terms, as if describing to a jury: are fingerprints unique?
tbd
94
practice question, answer in layman's terms, as if describing to a jury: are fingerprints a reliable means of identifications? why?
tbd
95
practice question, answer in layman's terms, as if describing to a jury: how is a latent print left on an item?
tbd
96
practice question, answer in layman's terms, as if describing to a jury: how do you compare latent prints?
tbd
97
practice question, answer in layman's terms, as if describing to a jury: what do you base your identification on?
tbd
98
what is a discrepancy in an impression? compared to a dissimilarity?
-- discrepancy: the presence of friction ridge detail in one impression that does not exist in the corresponding area of another impression
-- dissimilarity: a difference in appearance between two friction ridge impressions
99
how would you sequentially process a piece of white paper with ink?
visual - DFO, ninhydrin, indanedione - laser/ALS
(maybe nin-hexane to keep ink from running?)
100
how would you sequentially process a piece of dark or multicolored paper?
visual - DFO, ninhydrin, indanedione - laser/ALS
(maybe DFO or indanedione because it fluoresces against the dark background?)
101
how would you sequentially process a piece of plain cardboard?
visual - DFO, ninhydrin, indanedione - laser/ALS
(maybe nin-hexane for cardboard?)
102
how would you sequentially process a piece of thermally processed paper (receipt)?
visual - DFO, ninhydrin, indanedione - laser/ALS
(maybe nin-HT for thermal paper?)
103
how would you sequentially process a piece of tin foil?
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
104
how would you sequentially process a plastic ziplock bag?
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
105
how would you sequentially process an orange plastic folder?
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
106
how would you sequentially process an aluminum can?
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
107
how would you sequentially process a plastic or glass bottle? what if it has a paper label on it?
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
after non-porous process, use porous process:
visual - DFO, ninhydrin, indanedione - laser/ALS
108
how would you sequentially process a magazine or pamphlet?
if super glossy/non-porous:
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
if not coated/regular paper:
visual - DFO, ninhydrin, indanedione - laser/ALS
(maybe nin-hexane to keep ink from running?)
109
how would you sequentially process a semi-glossy box?
the glossy outside of the box:
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
the inside of the box, assuming raw cardboard:
visual - DFO, ninhydrin, indanedione - laser/ALS
(maybe nin-hexane for cardboard?)
110
how would you sequentially process an impression left in blood?
visual - amido black or leuco-crystal violet
(depending on surface; amido for non-porous, LCV for porous or semi)
111
how would you sequentially process a can or bottle with a sticky substance on the side?
visual - sudan black
(can also be used post-CA)
112
how would you sequentially process a piece of clear packing tape?
visual - non-adhesive side CA - adhesive side crystal violet or wetwop - non-adhesive side dye stain and powder
113
how would you sequentially process a piece of duct tape?
visual - non-adhesive side CA - adhesive side crystal violet or wetwop - non-adhesive side dye stain and powder
114
how would you sequentially process a piece of black electrical tape?
visual - non-adhesive side CA - adhesive side crystal violet or wetwop - non-adhesive side dye stain and powder
115
how would you sequentially process a piece of waxed paper?
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
116
how would you sequentially process a gun?
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
117
how would you sequentially process a piece of raw wood? what about finished wood?
raw wood:
visual - DFO, ninhydrin, indanedione - laser/ALS
(maybe nin-acetone for wood?)
finished/laquered/painted/varnished wood:
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
118
how would you sequentially process a vinyl surface, like car upholstery or a purse?
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
119
how would you sequentially process a rough-surfaced molded plastic?
visual - CA fuming - fluorescent dye stain - laser/ALS - powder
*could also lift the powdered print off the object using silicone casting material! from something like a golfball where you couldn't tape lift
120
how would you sequentially process a piece of fabric?
looking for any fingerprints:
maybe ninhydrin or indanedione? it would probably have to be a fabric with a tight weave or smooth finish, like satin. probably wouldn't work on wool or fabric that's really textured
if the fingerprint is in blood on the fabric:
leuco-crystal violet (better on porous than amido black)
121
how would you sequentially process a fingerprint on someone's skin?
apparently it can be done using CA fuming and some powders, but it's not commonly done; also there is a special paper/lift card where you can lift the print from the skin (mirrored) and then powder the card
