FDC FDC Quality Assurance & Accreditation 2 — Questions and Answers
Question 1: What is an administrative review in forensic DNA casework?
- A second scientific evaluation of the DNA data
- A review for completeness, consistency, and clerical accuracy of the case record (Correct answer)
- An audit of laboratory reagent inventory
- A supervisory approval of the analyst's training file
Correct answer: A review for completeness, consistency, and clerical accuracy of the case record
Administrative review checks that documentation is complete, signatures are present, and the report is consistent with laboratory policies — it does not re-evaluate the scientific data.
Question 2: What must a laboratory do when a contamination event is confirmed in a forensic DNA case?
- Discard the case evidence and request new samples
- Investigate the source, document findings, take corrective action, and notify affected parties (Correct answer)
- Immediately suspend all casework until reaccreditation
- Notify the FBI CODIS Unit within 24 hours
Correct answer: Investigate the source, document findings, take corrective action, and notify affected parties
When contamination is confirmed, the laboratory must conduct a root cause investigation, implement corrective action, and notify relevant parties such as the submitting agency.
Question 3: Which document defines the specific steps an analyst must follow to perform a DNA analysis procedure in a forensic lab?
- Case report
- Technical review checklist
- Standard Operating Procedure (SOP) (Correct answer)
- Proficiency test summary
Correct answer: Standard Operating Procedure (SOP)
A Standard Operating Procedure (SOP) provides step-by-step instructions for performing laboratory procedures and must be approved and kept current.
Question 4: What is the purpose of an analytical threshold (AT) in STR interpretation?
- To set the maximum allele size for accurate sizing
- To define the minimum peak height above which data is considered reliable for interpretation (Correct answer)
- To establish the maximum number of contributors in a mixture
- To determine the minimum DNA quantity required for CODIS upload
Correct answer: To define the minimum peak height above which data is considered reliable for interpretation
The analytical threshold defines the minimum peak height (RFU) at which a signal is considered a true allele rather than instrument noise.
Question 5: During a laboratory audit, an auditor finds that an analyst deviated from the SOP without documentation. What is the typical consequence?
- The case results are automatically invalidated
- A corrective action is required and the deviation must be documented and evaluated (Correct answer)
- The analyst is immediately suspended pending review
- The laboratory's CODIS privileges are revoked
Correct answer: A corrective action is required and the deviation must be documented and evaluated
Undocumented SOP deviations require a corrective action report and an evaluation of whether the deviation affected case results.
Question 6: What is a stochastic effect in low-template DNA analysis?
- Random PCR amplification bias that can cause allele dropout, drop-in, or peak height imbalance (Correct answer)
- Contamination from the analyst's own DNA
- Degradation of the sample during extraction
- Incorrect sizing of STR alleles due to CE instrument drift
Correct answer: Random PCR amplification bias that can cause allele dropout, drop-in, or peak height imbalance
Stochastic effects occur with low DNA template quantities and result in random amplification variation, including allele dropout (missing alleles) and drop-in (spurious alleles).
FDC FDC Quality Assurance & Accreditation 2
What is an administrative review in forensic DNA casework?