• Quality assurance (QA) for forensic services requires certain processes to ensure that a service will meet laboratory requirements for the integrity of testing.

• A QA program must include components that address:

  • Continuing education, training, and certification of personnel

  • Specification and calibration of equipment and reagents

  • Documentation and validation of analytic methods

  • Use of appropriate standards and controls

  • Sample handling procedures

  • Proficiency testing

  • Data interpretation and reporting

  • Audits (internal and external) and laboratory accreditation

  • Corrective actions to address deficiencies and assessments for laboratory competence

• Quality control (QC) for forensic services refers to the operational procedures necessary to meet quality requirements.

26.1 US Quality Standards

• The first published NRC report included recommendations in the areas of:

  • technical considerations;

  • statistical interpretations;

  • laboratory standards;

  • data banks and privacy;

  • legal considerations; and

  • societal and ethical issues related to forensic DNA testing.

• The NRC report attempted to explain the basic scientific principles of forensic DNA technology and made suggestions for applications and improvements. However, the report received negative criticism from both the forensic and the legal communities.

• A second NRC committee was formed “to update and clarify discussion of the principles of population genetics and statistics as they apply to DNA evidence.”

• The NRC II report consisted of:

  • an introduction describing the 1992 report, changes made subsequent to that report, and the validity and application of DNA typing techniques;

  • assurance of high standards of laboratory performance;

  • population genetics issues;

  • statistical issues; and DNA evidence in the legal system.

• DNA Advisory Board (DAB): It was formed as a result of the DNA Identification Act (1994) passed by Congress in 1995. It only served from 1995 to 2000 to develop guidelines for quality assurance in forensic laboratories.

  • Quality Assurance Standards for Forensic DNA Testing Laboratories

  • Quality Assurance Standards for Convicted Offender DNA Databasing Laboratories

• Scientific Working Group on DNA Analysis Methods (SWGDAM): Its purpose is to facilitate forensic DNA community discussions regarding necessary laboratory methods and to share protocols for forensic DNA testing.

• The SWGDAM established and revised several guidelines including the Guidelines for

  • Quality Assurance Program for DNA Analysis

  • Quality Assurance Standards for Forensic DNA Testing Laboratories

  • Quality Assurance Standards for DNA Databasing Laboratories

  • Validation Guidelines for DNA Analysis Methods

  • SWGDAM Training Guidelines

26.2 International Quality Standards

• International Society for Forensic Genetics (ISFG): Recognized the potential of DNA testing for criminal investigations and made a number of recommendations related to the forensic application of DNA polymorphisms.

• European DNA Profiling Group (EDNAP): It has investigated systems for DNA profiling, has organized a number of collaborative exercises for the evaluation of new methods, and has published reports of its studies.

• European Network of Forensic Science Institutes (ENFSI): Formed its DNA working group to address issues of quality and standards for forensic DNA testing.

• Interpol European Working Party on DNA Profiling (IEWPDP): It also made recommendations for applying DNA evidence to criminal investigations in Europe.

• Based on the EDNAP exercises and recommendations by the ENFSI and IEWPDP, the European Standard Set (ESS) for autosomal STR core loci was established.

• Standardization of DNA Profiling Techniques in the European Union (STADNAP): A group that has been working on the selection of forensic DNA profiling systems, methods for use among European countries, and the maintenance of European population databases.

26.3 Laboratory Accreditation

• Accreditation: The process used to assess the qualification of a laboratory to meet established standards.

• The accreditation process generally involves several components such as self-evaluation, the preparation of supporting documents, on-site inspection and reports, and accreditation review reports.

• Accreditation in the United States is offered by the Laboratory Accreditation Board of the American Society of Crime Laboratory Directors (ASCLD/LAB) for forensic laboratories performing casework.

• American Association of Blood Banks (AABB): Provides accreditation for laboratories performing DNA parentage testing according to the AABB’s standards.

26.4 Laboratory Validation

• Validation: The process of confirming that a laboratory procedure is sufficiently robust, reliable, and reproducible.

  • A robust method maintains successful performance and can cope with errors.

  • A reliable method produces accurate results.

  • A reproducible method achieves the same or very similar results each time a sample is tested.

• Two types of laboratory validations:

  • Internal validation: An accumulation of test data within the laboratory to demonstrate that established methods and procedures perform as expected in the laboratory.

  • Developmental Validation: The acquisition of test data and determination of conditions and limitations of a new or novel DNA methodology for use on forensic, database, known or casework reference samples.

• Precision: Characterizes the degree of mutual agreement among a series of individual measurements, values and/or results. It depends only on the distribution of random errors and does not relate to the true value or specified value.

• Accuracy: The ability of a measuring instrument to give responses close to a true value.

26.5 Proficiency Testing

• It is an important component of quality control and quality assurance.

• It evaluates a laboratory’s performance of DNA analyses according to the laboratory’s standard protocols.

• It also evaluates the quality of performance by individual analysts following laboratory protocols.

• Proficiency tests of DNA analysts must be conducted every 6 months based on DNA Advisory Board Standards.

• The testing usually involves mock forensic case samples including questioned bodily fluid stains and reference samples.

• The test is assigned to an analyst for processing according to the laboratory procedures. A report must be prepared and is then reviewed.

• Blind Test: The analyst is not aware that he or she is being tested. It is considered a more effective means of evaluating performance.

26.6 Certification

• Certification: A voluntary process that recognizes the attainment of professional qualifications needed for practice in forensic services. It is not required, but is desired by some laboratories.

• In the United States, the American Board of Criminalistics (ABC) offers three types of certification for forensic scientists.

  • A diplomate must pass a general knowledge examination.

  • ABC also requires a bachelor’s degree in a natural science and 2 years of experience in a forensic laboratory.

  • To obtain fellow status, an applicant must have 2 years of experience in his or her specialty and must have met the diplomate requirements in addition to passing a written specialty examination and a proficiency test

26.7 Forensic DNA Analyst Qualifications

• DAB’s Quality Assurance Standards for Forensic DNA Testing Laboratories require that an examiner or analyst have:

  • At a minimum a BA/BS degree or its equivalent degree in a biology, chemistry or forensic science-related area and must have successfully completed college course work covering the subject areas of biochemistry, genetics and molecular biology,

  • Course work and/or training in statistics and population genetics as it applies to forensic DNA analysis.

• Biochemistry: The nature of biologically important molecules in living systems, DNA replication and protein synthesis, and the quantitative and qualitative aspects of cellular metabolism.

• Genetics: The study of inherited traits, genotype/phenotype relationships, and population/species differences in allele and genotype frequencies.

• Molecular biology: It covers theories, methods, and techniques used in the study and analysis of gene structure, organization, and function.

26.8 Code of Ethics of Forensic Scientists

• Ethical codes for forensic scientists are used as guides for individuals making their decisions in distinguishing the difference between correctness and incorrectness.

• Failure to comply with a code of forensic practice can raise doubt in an individual’s fitness for providing forensic services.

• A typical document of ethical codes for forensic scientists generally contains five sections:

  • ethics relating to the scientific method;

  • ethics relating to opinions and conclusions;

  • ethical aspects of court presentation;

  • ethics relating to the general practice of forensics; and

  • ethical responsibilities to the profession.