FIS 480 EXAM #2 REVIEW QUESTIONS AND
ANSWERS A+ GRADED
Sampling
Taking part of a substance, material, or product for testing in order to reach a
conclusion, make an inference about, and report on the whole.
Sample Selection
A practice of selecting items to test, or a portion of items to test, based on forensic
scientists training, experience and competence
Does Sampling or Sample Selection require Homogeneity?
Sampling
What disciplines put more emphasis on sampling?
Drug Chemistry (Pills, powders, plants, etc.)
What disciplines put more emphasis on sample selection?
Blood, body fluids etc (Disciplines where stains must be collected)
What must be addressed in the handling of items of evidence/test items?
Procedure must address transportation, handling, receipt, protection against damage,
deterioration and loss, storage, retention and disposal, identification, suitability and
traceability
What must all items of evidence have on their label?
Date of Collection
Name of Individual who retrieved
Individual ID for *ALL EVIDENCE*
Assuring Quality of Results: How do we do that?
Proficiency Tests
Reference Materials
Reference Standards
Individual Characteristic Database Sample
Samples that all follow the same evidential rules (chain of custody, unique ID, maintain
security)
Evidence like this requires all of the same qualities that regular evidence does
Documentation at Crime Scene
Everything must be PERMANENT
(If writing is in pencil, make permanent unalterable copy for record)
Running samples that go bad (non-accurate data): Where does it go?
All tests and runs must go into case file, even if not accurate
Verification
the process of establishing the truth, accuracy, or validity of something.
Technical Review
evaluation of reports, notes, data, and other documents to ensure there is an
appropriate and sufficient basis for the scientific conclusions.
What must be included in a technical review?
Sample Size
Accuracy
, Discrepancies
Discipline/Subdiscipline
Include Case file, report, testimony
*Do not tech review own work*
Test Report Requirements
Results
Methodology
Conclusions
Statement of Opinions
Customer Info
Performers of Tests
Standard Methods
Published procedures that are usually held as the norm when performing that task
Non-Standard Method
Published method that is not usually followed as the standard
Lab Method
Method created in a laboratory as a procedure for a specific instrument
Internal Validation
the accumulation of test data within the laboratory to demonstrate that established
methods and procedures perform as expected in the laboratory.
Developmental Validation
is the acquisition of test data and determination of conditions and limitations of a new or
novel DNA methodology for use on forensic and/or casework reference samples.
Precision
a measure of how close a series of measurements are to one another
Accuracy
how close a measurement is to the true value
Repeatability
Variation in measurements taken by a single person or instrument on the same item
and under the same conditions
Reproducibility
ability to obtain the same results for experiments or observations by doing the same
experiment or making the same observation in the same way.
Limit of Detection
Lowest concentration of Analyte detected by laboratory instrument.
Limit of Quantification
Lowest CONCENTRATION quantifiable in the lab.
Usually higher than LOD.
Requirements for Procedures
•Purpose and Scope
•References
•Roles and Responsibilities
•Parameters to be measured, range of values to be measured, accuracy and resolution
required
•How and when samples will be taken
•Specify sample size
ANSWERS A+ GRADED
Sampling
Taking part of a substance, material, or product for testing in order to reach a
conclusion, make an inference about, and report on the whole.
Sample Selection
A practice of selecting items to test, or a portion of items to test, based on forensic
scientists training, experience and competence
Does Sampling or Sample Selection require Homogeneity?
Sampling
What disciplines put more emphasis on sampling?
Drug Chemistry (Pills, powders, plants, etc.)
What disciplines put more emphasis on sample selection?
Blood, body fluids etc (Disciplines where stains must be collected)
What must be addressed in the handling of items of evidence/test items?
Procedure must address transportation, handling, receipt, protection against damage,
deterioration and loss, storage, retention and disposal, identification, suitability and
traceability
What must all items of evidence have on their label?
Date of Collection
Name of Individual who retrieved
Individual ID for *ALL EVIDENCE*
Assuring Quality of Results: How do we do that?
Proficiency Tests
Reference Materials
Reference Standards
Individual Characteristic Database Sample
Samples that all follow the same evidential rules (chain of custody, unique ID, maintain
security)
Evidence like this requires all of the same qualities that regular evidence does
Documentation at Crime Scene
Everything must be PERMANENT
(If writing is in pencil, make permanent unalterable copy for record)
Running samples that go bad (non-accurate data): Where does it go?
All tests and runs must go into case file, even if not accurate
Verification
the process of establishing the truth, accuracy, or validity of something.
Technical Review
evaluation of reports, notes, data, and other documents to ensure there is an
appropriate and sufficient basis for the scientific conclusions.
What must be included in a technical review?
Sample Size
Accuracy
, Discrepancies
Discipline/Subdiscipline
Include Case file, report, testimony
*Do not tech review own work*
Test Report Requirements
Results
Methodology
Conclusions
Statement of Opinions
Customer Info
Performers of Tests
Standard Methods
Published procedures that are usually held as the norm when performing that task
Non-Standard Method
Published method that is not usually followed as the standard
Lab Method
Method created in a laboratory as a procedure for a specific instrument
Internal Validation
the accumulation of test data within the laboratory to demonstrate that established
methods and procedures perform as expected in the laboratory.
Developmental Validation
is the acquisition of test data and determination of conditions and limitations of a new or
novel DNA methodology for use on forensic and/or casework reference samples.
Precision
a measure of how close a series of measurements are to one another
Accuracy
how close a measurement is to the true value
Repeatability
Variation in measurements taken by a single person or instrument on the same item
and under the same conditions
Reproducibility
ability to obtain the same results for experiments or observations by doing the same
experiment or making the same observation in the same way.
Limit of Detection
Lowest concentration of Analyte detected by laboratory instrument.
Limit of Quantification
Lowest CONCENTRATION quantifiable in the lab.
Usually higher than LOD.
Requirements for Procedures
•Purpose and Scope
•References
•Roles and Responsibilities
•Parameters to be measured, range of values to be measured, accuracy and resolution
required
•How and when samples will be taken
•Specify sample size
