FKA3 Flashcards
When processing the scene of a death, what are some considerations prior to moving the body?
Photographs
Visual examination - consider using a LS laser or flashlight
Notes
Preserve evidence on hands and feet and head by bagging as necessary
Physical measurements
Name the common biohazards associated with violent crime or death scenes, as well as which artifacts within the scene present biohazrds
Blood
Urine
Faecal matter
Spit
Vomit
Needles
Airborne particles
Biohazard’s include communicable diseases, such as HIV and hepatitis
What is adipocere?
A great white matter produced by the hydrolysis and hydrogenation of lipids. The formation is facilitated by cold, wet and anaerobic conditions or environments. Depending on the conditions it can begin to form as early as two weeks to a month. Tissues kept in plastic or immersed make show uniform information.
What is forensic odontology?
The application of the signs of dentistry, to the field of law, or investigation of a crime. It can be helpful in identifying human remains through bite analysis and can also be used for bite mark analysis. dental patterns are unique and cannot be burned or cut to change the pattern.
In nanometers what is the wavelength of visible portion of the electromagnetic spectrum?
400 nm to 700 nm
Define thermoluminescence
When light is emitted as a result of heating an object.
Example heating element of a stove
Define chemiluminescence
When light is emitted as a byproduct of a chemical reaction
Example glow sticks or blue star/Luminol
Define bioluminescence
When light is emitted by an organism
Example fire flies
Define photoluminescence including phosphorescence and fluorescence
Photoluminescent is the emission of light as a result of absorbing incident light
Phosphorescence occurs when the emission of light continues after the light source is removed. Example glow-in-the-dark stickers.
Fluorescence occurs when the emission of light stops after the light source is removed. Example chemical dyes used in exhibit processing.
During the process of qualifying yourself as an expert in court defence council asks you are you an expert in the location, development collection, analysis, and identification of fingerprints. How would you answer this?
These are all part of my duties as a member of forensic identification services, the determination of whether I am qualified as an expert lies with the courts. I am confident that based on my knowledge, training and experience, I am able to provide accurate expert testimony.
Often forensic identification personnel will make reference in their reports to unsuitable friction ridge impressions. How would you clarify this expression to the courts to reflect your impartiality?
A suitable impression is one that through a thorough analysis is determined to contain sufficient detail or information that can be used to identify or exclude a known source.
How are fingerprints or physical evidence developed at a crime scene to be marked prior to photographing and lifting?
R#
Date
File number
Examiners initials
Demarcation line or circle around the impression
An arrow pointing up on vertical surfaces to assist in determining directionality
is it likely that the ridge detail of a fingerprint which with is developed with chemistry powder can be further enhanced by the application of lightning gray powder? What about the reverse?
Yes, lightning gray powder is a finer powder that can be used to clean up an impression initially developed with chemist grey. However, chemist gray cannot be used after the application of lightning grey powder, as this will obliterate the impression.
What method would you use to develop or enhance a fingerprint on a waxy or oily surface?
Cyanoacrylate fuming and chemical dyes
Fluorescence exam
Sudan black
And chemist grey powder
List two recommended methods of developing or enhancing latent fingerprints on plastic bags
Cyanoacrylate fuming and possible chemical dye staining
Vacuum metal deposition
If silver gray powder is used to examine a black plastic cash register tray what will probably happen to the fingerprint powder when it is applied?
The powder will flood the surface, obliterating any impressions
List two recommended methods of lifting a finger print from a very rough or oddly shaped surface
Rubber casting compound
Gel lifter
Gel glue or caulk
Where were you find the recommended formula for preparing ninhydrin working solution
Standardized operating guidelines number 411
Chemical recipe book in lab
Which technique is recommended for developing fingerprints on wet or damp, nonporous surfaces
Small Particle Reagent
Molybdenum disulphide
How can you intensify a week fingerprint developed with magnetic fingerprint powder
Blowing a guttural breath over the impression
Chemical processes
Describe the cyanoacrylate fingerprint development process
Cyanoacrylate is heated within a humidity chamber, creating cyanoacrylate vapors. The vapours polymerize in the presence of humidity and form a white deposit or film on the fingerprints on non-porous surfaces. The impressions may be visualized alone, or may require the use of chemical dyes.
Name five different chemical reagents that could be used to enhance fingerprints in blood
Aqueous leuco crystal violet
Acid black one (amido black)
Acid Violet 17
Acid yellow 7
DFO
Ninhydrin
Vacuum metal deposition
Hungarian red
Comassee blue
How would you enhance a friction ridge impression believe to be in blood on a dark coloured non-porous surface?
Fluorescence exam
Infrared photography
Chemist grey powder
Acid yellow 7
Methyl based titanium dioxide
Acid violet 17
Will cyanoacrylate fuming interfere with the acid yellow 7 and acid violet 17 development of a bloody impression on a non-porous surface
Yes, the deposit/film left by the cyanoacrylate fuming will prevent these chemicals from interacting with the impression or stain
Explain the proper procedure to conduct a presumptive test of a steam suspected to be blood using a human sticks, and what precautions should be taken
Wearing appropriate PPE (gloves)
Use a sterile swab wetted with distilled water
Rub the swab against the stain
Touch the swab to the test strip
Take note of the colour change dark green indicates a presumptive positive test for blood
Indirect testing is the preferred method as direct testing can contaminate the sample and affect the subsequent DNA testing at the lab. If direct testing is used, the lab should be notified.
Dispose of the swab and test strip with biohazard waste
What are the three main categories of blood stains encountered at crime scenes?
Transfer
Spatter
Passive or gravity
List seven factors that may be determined by the analysis of blood stains
Direction to drop was travelling when deposited
Approximate point of origin
Minimum number of blows or impacts
Relative positions of persons/victim, and or other objects during bloodshed
Movement of persons or objects, during and after bloodletting events
Movement of persons shedding blood
Distance between target and source of blood
Type and direction of impact
In a scene where are you suspect blood has been cleaned up prior to any chemical used. How would you conduct your visual examination and where?
Using a white light/flashlight examine:
Between cracks in flooring
Spindles of bannisters and chairs
Undersides of furniture
Kickboards of cabinets
Behind doors
Slots of blinds and window coverings
Ceilings
Louvres of vents
How is infrared photography helpful in documenting blood stain patterns on some surfaces?
Capturing an image using infrared photography can assist by providing contrast when a background of a steam is an issue, for example, dark or multi coloured backgrounds.
Is Luminol a presumptive test for blood
Yes, the chemical reacts with the human blood and produces chemiluminescence. False positives are possible when in contact with iron, rich substances, bleach animal, urine faecal matter, certain metals and plant peroxidase.
Name three basic types of construction used to manufacture tires
Radio
Bias ply
Bias belted
Name 7 of the 14 basic components of the modern radial tire
Bead
Bead toe
Bead heel
Bead area apex
Bead region
Belts
Breakers
Cap
Chafer
Liner
Ply
Sidewall
Shoulder
Tread
In a forensic tire examination, it is important to know whether a tire was manufactured before or after the date of the offence for which the tires alleged to have been involved. What would give the indication of when the tire was manufactured?
The last four digits of the serial number provide the week and year of manufacture
What is meant by the term mold rotation or mold offset
This occurs when the top and bottom house of full circle molds, do not line up perfectly, and are slightly offset when they close during the curing process
Name two annual publications, which can assist in identifying possible automotive tire brand names
Who makes it and where?
Tread design guide
List three of the five factors that may cause irregular or accelerated wear on vehicle tires
Camber
Toe in/toe out
Overinflation
Under inflation
Improper balance
An integral part of the forensic analysis and comparison of a vehicle tire impression is the identification of the noise treatment. Explain the term and its significance to the analysis.
Noise treatment is the variable sequence of different sizes of elements in the tread pattern around the entire circumference of the tire.
It can be used to identify the area of tread/tire to focus on during a comparison of an unknown impression.
A vehicle tire impression has been linked to a crime scene. Research indicates that the tire with that particular tread pattern is manufactured by Goodyear but the suspect vehicle has Moto master tires. Explain how this could occur.
Goodyear sold the mold to motomaster, or Goodyear manufactured the tires for motomaster
What is the recommended procedure to measure the wheelbase of a vehicle using only its tire tracks?
Measure from the leading edge of the rear tire track to the leading edge of the front tire track on each side. Both sides are measured to ensure accuracy.
Explain the procedure to determine the track with of a vehicle based on his tire marks which have been left in the dirt.
Determine the centerpoint of each of the front tracks, and measure from Centerpoint to Centerpoint. Repeat for the rear tracks if available.
To avoid damaging a three-dimensional impression in snow, when using liquid sulphur as the casting medium, what is the most critical time prior to pouring?
When crystals begin to form
What concerns were raised by the NAS committee pertaining to friction ridge examination and more specifically the ACE–V methodology?
A- ACE–V provides a broadly stated framework for conducting friction ridge analysis
B- the framework is not specific enough to qualify as validated method for this type of analysis.
C- does not guard against bias
D- Does not guarantee that two analysts following it will obtain the same results.
E- following it doesn’t imply one is proceeding in a scientific manner or producing reliable results.
The NAS report outline 13 recommendations. Briefly explain how these recommendations impact the policies and procedures of the RCMP.
- standardized training, and certification process
- Standardized operating guidelines established
- Standardized forms, documentation, and reporting.
- Quality assurance practices, including opinion verifications, unit level file reviews, and management reviews.
- Standardized procedures for processing crime scenes, and analyzing impression evidence.
According to the PCAST report, what to Black Box studies validate the ACE-V process?
FBI/Noblis
Miami-Dade
According to the OSAC response to the PCAST report, what is the correct false positive rate in the Miami-Dade Black Box study?
0.19%.
Other than Brandon Mayfield and Shirley McKay cases, name three lesser known cases, where erroneous in visualizations resulted in the wrong individual being in prison. Quote your references.
1 - Stephen Cowans- 2004- in 1997 Cowans was convicted of shooting a police officer in Boston, Massachusetts. Evidence included the identification of a fingerprint on a drinking glass associated with the scene. Cowens was exonerated in 2004 by DNA evidence I miss labelled fingerprint card was alleged to be the source of the error.
2- Lana Canen - 2012- in 2005 Canen was convicted of murdering her neighbour in Elkhart, Indiana. The conviction was partially based on a fingerprint identification. After the fingerprint evidence was reviewed by an independent examiner and established to be an error. The examiner, who lacked training in the field of latent fingerprint comparisons, admitted making the erroneous identification and head overstated his qualifications of the original trial.
3- Richard Jackson - 2000 – in 1998 Jackson was convicted of murdering Alvin David in Delaware county Pennsylvania. The conviction was based on an erroneous fingerprint identification. The two independent examiners have determined the error just days before the trial, Jackson was still convicted. In 2000 Jackson was released. The upper Darby police in the original examiner, who made the identification standby their opinions.
What is cognitive bias?
A general term for mini observer effects on the human mind, some of which can lead to perceptual distortion, inaccurate judgment, or illogical interpretation. It includes confirmation bias, which connotes the seeking or interpreting of evidence, in ways that are partial to existing beliefs, expectations, or a hypothesis in hand.
What is meant by adequate documentation?
It serves to provide a record of the process, followed by an examiner. It describes the steps and procedure followed by the examiner in a way that is easy to understand and captures the examiners interpretive judgements in a way that would permit the examiner, or another examiner, to make sense of the decision at a later time. It maximizes transparency.
What conclusions were drawn from the 2011 FBI and Noblis corporation study into error rates?
False positive rate - 0.1%.
False negative rate - 7.5%.
What is meant by interexaminer agreement?
Also repeatability, refers to whether to examiners reach the same decision on the same fingerprints.
What is meant by intra examiner agreement?
Also reproducibility, refers to whether an examiner consistently reaches the same decision on the same fingerprints.
What percentage of identification decisions were repeated by examiners?
89.1%
What is meant by sufficiency
The product of the quality and quantity of the objective data under observation. As the quality of an impression increases the need for quantity of friction, ridge features decreases, as well as the inverse.
What conclusions were drawn from the sufficiency study?
1-in erroneous identification to examiners noted minutia that seemed out of tolerance. Probabilistic assessments could have function as a quality assurance mechanism.
2-sufficiency is mainly driven by quality, quantity, and spatial relationships of minutia.
3-the use of statistical tools may prove useful in strengthening decisions made by examiners.
4-there’s lack of understanding of sufficiency in cases of exclusions.
5-there’s lack of standardization in the definition of minutia.
6-the lack of standardization extends to other aspects of examinations such as distortion, degradation, influence of background, and development techniques.
7-there’s urgent need to develop standards and training to ensure consistency in the definition of minutia, both in the analysis and comparison phases.
According to the OIG, what factors were attributed to the erroneous identification of Brandon Mayfield?
1-the unusual similarity of the prints.
2-bias from the knowns of Mayfield.
3-faulty reliance on level 3 details.
4-inadequate explanations for differences.
5-failure to assess the poor quality of similarities.
6-failure to re-examine LFP17 after the April 13 negativo report.
What led to the publication of the fingerprint inquiry report?
In 1997 a fingerprint collected at the scene of a homicide in Scotland, was miss identified to an investigator by the name of Shirley McKie. Following the acquittal of the person charged with the original homicide, the fingerprint inquiry was set up and carried out in order to identify any shortcomings in the case, and make recommendations as to what measures might be introduced to ensure similar misidentifications are avoided in the future.
What were the key findings of the fingerprint inquiry report?
1-Y7 what is the only evidence to suggest that Ms.McKie enter the house beyond the area of the porch.
2-Y7 was found on the door frame of the bathroom of the house, and was miss identified as the fingerprint of Ms.McKie.
3-Ms. McKie did not make mark Y7.
4-there is no conspiracy against Ms. McKie in Strathclyde police. All reasonable steps were taken by them to seek confirmation from the SCRO of the identification of Y7.
5-the mark QI2 Ross what is misidentified as the fingerprint of Miss Ross.
6-there is no impropriety on the part of any of the SCRO, fingerprint examiners, who made the misidentifications.
7-Y7 and QI2 Ross we’re both miss identified by SCRO fingerprint examiners due to human error.
8-The misidentifications expose weaknesses in the methodology of fingerprint comparison. Particularly that out of complex impressions.
9-Fingerprint examiners are presently ill-equipped to reason their conclusions, presently regarding them as a matter of certainty and seldom challenged.
10-there’s no reason to suggest that fingerprint comparison in general is inherently unreliable, but consideration should be given to the limits of the discipline.
What were the key recommendations of the fingerprint inquiry report?
1-fingerprint evidence should be recognized as opinion evidence, not fact.
2-examiners to discontinue reporting conclusions with a claim to 100% certainty.
3-examiners should receive training which emphasizes that their findings are based on personal opinion.
4-differences of opinion should not be referred to as disputes.
5-the SPSA standard operating procedures should detail the ACE–V process.
6-features of a finger mark being relied upon, should be demonstrable to a lay person with normal eyesight as observable.
7-clear explanations of any differences should be required if a finding of identification is made.
8-finding of identification should not be made if there is an explained difference between a mark and a print.
9-the SPSA should develop a process to ensure that complex marks are treated differently.
10-an emphasis needs to be placed on the importance of learning and practising the methodology of fingerprint work, and engaging with members of the academic community working in the field.
11-examiner should be trained to be conscious of the risk of contextual bias.
