The goal of a laboratory's trace evidence analysis program is to provide quality trace evidence assessment, identification, comparison, and reconstruction associated with forensic investigations. These guidelines provide a framework of standards for quality in the processing of trace evidence collection, handling, analysis, reporting, and testimony.
1.1. A quality assurance program must be established and maintained. The personnel responsible for the program must have it clearly stated in their position descriptions and should have direct authoritative access to the highest level of management concerning laboratory policy. Standard operating procedures must document who may take what action, whether approval is required, and from whom approvals are needed.
1.2. The quality assurance program must ensure that all procedures, examinations, and reports associated with trace evidence are within the established guidelines.
This document pertains to the personnel performing trace evidence examinations in forensic laboratories.
Administrative Review: Review of a report for compliance with laboratory policy and editorial correctness.
Audit: An inspection to evaluate laboratory function and compliance with established criteria.
Calibration: The process of assigning a known value, within specified limits, to an instrument's scale reading.
Examiner: Personnel who receive and examine evidence, interpret results, write reports, and testify to casework findings.
Proficiency Test: Personnel and laboratory evaluation through the examination and interpretation of a prepared sample.
Quality Assurance: Planned actions to provide confidence that a service will meet certain requirements.
Quality Control: Daily operational procedures designed to ensure quality results.
Reference Sample: A material of known physical characteristics authenticated by a certified procedure accompanied by or traceable to documentation.
Structured Courses: Courses providing continuing education credit or courses documenting specific goals and that have detailed agendas and written examinations testing student comprehension.
Support Analysts: Personnel highly trained and knowledgeable in the operations of specialized laboratory instrumentation. These personnel are responsible for instrument operation and the analysis of evidence utilizing these instrument. According to state and/or laboratory policy, the support personnel may be required to provide a written report and testify to the interpretations in a court of law.
Systematic Error: Any discrepancy due to improper instrument function.
Technical Peer: An examiner technically current and competent in the same trace discipline.
Technical Review: Report review by a technical peer for content and supporting data.
Technicians and Laboratory Aides: Personnel who provide laboratory support and assist with the basic functions of the section. These functions should be specified by laboratory policy and may include preparing reagents, cleaning glassware, ordering supplies, and preparing samples for examination.
Trace Evidence: Referring to the forensic discipline involving the examination of fibers, hairs, glass, and paint.
Validation: The acquisition of information needed to assess the reliability of a procedure and to determine the conditions under which results can be obtained.
The job descriptions for all personnel should include responsibilities, duties, and required skills.
4.1. Designated Personnel
4.2.1. Case Coordinator (However Named): Designated
personnel with extensive knowledge of the laboratory's capabilities
and of forensic science to prioritize cases and direct case flow.
4.2.3. Technician and Laboratory Aide
(However Named): Designated personnel who perform basic laboratory
duties but do not examine evidence.
4.2.5. Examiner (However Named): Designated
personnel who receive and examine evidence, interpret results,
write reports, and testify to casework findings.
4.3. Qualifications and Education
Examiners and support analysts will
These requirements must be completed within two years of the issuance of this document.
Technical leaders and technical consultants will
The laboratory must establish and document qualifying procedures or a training program for all new technician and laboratory aide, support analyst, and examiner trainees. Trace evidence training programs must enable the trainees to obtain the specialized knowledge and skills required to demonstrate ability in each discipline in which they will be qualified.
Technician and laboratory aide trainees must follow an outline showing an approximate time line for completion of training, including completion of a training manual covering the principles and methodology of tasks for which they will be responsible. A reference list may be used to supply this information.
Examiner and support analyst trainees must follow an outline showing an approximate time line for the completion of training, including the completion of a training manual covering principles, uses, and applications of the instruments and the methods and procedures applied during task performance. A reference list may be used to supply this information.
Examiner and support analyst trainees must observe an experienced examiner handling casework prior to working cases under the direct supervision of an experienced examiner. Prior to undertaking independent casework, examiner and support analyst trainees must demonstrate competency through successful completion of the following:
The laboratory must establish a documented means of recognition for the successful completion of training such as a certificate, letter, or memorandum.
4.4. Maintaining Qualifications
In order to maintain qualifications, a technical manager or technical consultant must annually
The forensic laboratory must maintain documentation on significant aspects of trace evidence analysis procedures, including any related documents or laboratory records pertinent to the analysis or interpretation of results, to create a documented audit trail. Documentation should also exist for the following areas.
5.1. Test Methods and
5.2. Authenticated Reference
5.3. Reagents Documentation (Date of Receipt, Opening, and Preparation)
5.4. Evidence-Handling Protocols
5.5. Equipment Calibration
and Maintenance Records
5.7. Proficiency Testing Data
5.8. Personnel Training and Qualification Records
5.9. Quality Assurance and Audit Records
5.10. Quality Assurance Manual
5.11. Safety Manuals
5.12. Material Safety Data Sheets
Only suitable and properly operating equipment should be employed. Monitoring of equipment parameters should be conducted and documented as specified in Sections 5.5. and 5.6. The manufacturer's operation manual for each instrument should be available at the work place.
Materials and chemicals must be of suitable quality and demonstrated to be compatible with the methods employed. Documentation must be maintained for chemicals and must include the date received and the date of opening or preparation. There must be written formulae for all chemical reagents produced in the laboratory. Labels for reagents prepared within the laboratory must include
Commercial and laboratory-prepared reagents must be tested against a reference sample prior to use in casework. The results of the test must be documented. Supplies must be inspected for cleanliness appropriate for the analysis performed.
The analysis of unknown trace evidence can be accomplished by a variety of methods. Nondestructive tests should be performed first. Limited sample size, the possibility of future analyses, and other limitations should be considered before destructive tests are performed. Appropriate reference samples or collections must be authenticated. Refer to established published procedures.
The laboratory's quality control guidelines should contain specific protocols to assess critical parameters in normal operations. Instruments must be routinely monitored to ensure that performance is maintained and documented. Instrumentation used in the analysis of trace evidence must be tested with reference standards, when appropriate, to ensure that the instruments are performing adequately.
Documentation must be maintained to create an audit trail that can be reviewed. Documentation must contain sufficient information to allow a technical peer to evaluate case notes and interpret the data.
Documentation should include data obtained through the analytical process. It should also include information regarding the packaging of the evidence upon receipt and the condition of the evidence. All documentation of procedures, standards, controls, observations, results of the tests, charts, graphics, photographs, printouts (hard copy and disk), spectra, and communications generated during an examination must be preserved according to written laboratory policy.
Reports should contain the following:
A case review should be conducted by a minimum of two personnel. The review should consist of a technical review and an administrative review. A technical review should be conducted on each report and the notes and data supporting the report must be reviewed independently by a technical peer. Once a report has been reviewed, initials or other appropriate markings must be maintained in the case file by the personnel conducting the review. An administrative review should be conducted on each report to ensure adherence to laboratory policy and editorial correctness.
Laboratory administration will determine the course of action if an examiner and the reviewer fail to concur.
Proficiency testing pertains to examiners, support analysts, technical managers, and technical consultants engaged in the field of trace evidence. At least one proficiency test must be completed annually by each of the personnel.
Test samples must be of sufficient quality so that a conclusion can be drawn from the results of the analysis. All test samples must be handled and stored appropriately to maintain their integrity and condition.
The following proficiency test data and information must be collected and submitted to the quality assurance coordinator or other designated personnel for evaluation:
The quality assurance coordinator or other designated personnel will review all test documentation and compare the results with the information received from the manufacturer of the test. The quality assurance coordinator will provide a written summary report for each proficiency test to the participating examiner or other appropriate personnel as established by the laboratory policy. This review should be conducted in a timely manner.
All original notes, records, and other data pertaining to the open proficiency test results must be retained according to laboratory policy.
Prior to a proficiency test, all participating laboratory personnel should be provided with the specific policies, procedures, and criteria for any corrective action that may be taken as a result of a discrepancy in a proficiency test.
It is the responsibility of the quality assurance coordinator or designated personnel to ensure that discrepancies are acknowledged, the reasons for any discrepancies are determined, and any subsequent corrective action is documented.
Any discrepancy in a proficiency test determined to be administrative (clerical, sample confusion, improper storage, or documentation) will be corrected according to established laboratory policy.
Any discrepancy in a proficiency test determined to be the result of a systematic error may require a review of all relevant casework since the trace evidence section's last successfully completed proficiency test using that equipment. Once the cause of the discrepancy has been identified and corrective action has been taken, examiners in the relevant area should be made aware of the appropriate corrective action.
Any difference in a proficiency test result proven to be the consequence of an analytical or interpretative discrepancy may prohibit the personnel who produced the discrepant result from further examination of case evidence until the cause of the discrepancy is identified and corrected. The quality assurance coordinator or designated personnel will determine the need to audit prior cases according to established laboratory policy.
Before resuming analysis or interpretation of casework, one additional proficiency test should be successfully completed by the personnel responsible for the discrepancy.
The results of all proficiency tests should be maintained by the laboratory according to established laboratory policy.
The laboratory will use validated techniques and procedures. Techniques and procedures (e.g., ASTM 1492-92) currently accepted by the scientific community should be considered valid.
New techniques developed for the characterization, identification, and comparison of trace evidence should be based on accepted scientific principles. Validation studies should be performed as soon as practicable to establish the technique's reliability.
It is important that the results of validation studies be shared as soon as possible with the scientific community through presentations at scientific and professional meetings and through timely publication in peer-reviewed, scientific journals.
Audits should be conducted at least once a year by the technical manager in conjunction with the personnel responsible for the quality assurance program.
Records of each audit should be maintained and should include the date of the audit, name of the person conducting the audit, findings, and corrective actions, if necessary.
The laboratory must establish an audit schedule. Case files to be reviewed should be chosen randomly.
The trace evidence laboratory should operate in accordance with the regulations of the pertinent government, environmental, health, biohazard and safety authorities, and laboratory policy.
General laboratory safety manual(s) should be readily available to all laboratory personnel.
A Material Safety Data Sheet (MSDS) file should be maintained for chemicals used in the laboratory. These data sheets should be updated regularly and be readily available to all laboratory personnel.
All chemicals, biohazards, and supplies must be stored and disposed of according to applicable government regulations and laboratory policy.
American Society of Crime Laboratory Directors-Laboratory Accreditation Board, ASCLD-LAB Accreditation Manual, 1994.
Garfield, F. M. Quality Assurance Principles for Analytical Laboratories, Association of Official Analytical Chemists, Library of Congress, 1991.
International Standards Organization/International Electrotechnical Commission, ISO/IEC Guide 25-1990, American National Standards Institute, New York, 1990.
OSHA. U.S. Department of Labor Occupational Safety and Health Administration. U.S. Government Printing Office, 1984.
Quality Assurance, Laboratory Management Practice Manual, American Council of Independent Laboratories, 1986.
TWGDAM. Guidelines for a Quality Assurance Program for DNA Analysis. Technical Working Group on DNA Analysis Methods, Crime Laboratory Digest (1995) 22:21-43.
FORENSIC SCIENCE COMMUNICATIONS JANUARY 2000 VOLUME 2 NUMBER 1