Which Standards Are Standard? Differences between ISO/IEC 17025 and 17020 for forensic agencies
The forensic community has been under attack for several years. The National Academy of Science issued its scathing report Strengthening Forensic Science in the United States: A Path Forward back in 2009. The news media have repeatedly questioned the soundness of forensic science laboratories and forensic law enforcement in general, and with reference to specific instances of wrongdoing.
To address the concerns raised by these reports, there is a growing trend among forensic agencies to seek accreditation to international standards that require a robust management system and technical competence. Becoming an accredited agency assures customers that the forensic agency complies with international standards and internationally recognized good practices, and that its staff is technically competent to perform specific types of testing and inspections.
To become accredited, the forensic agency must apply to an accreditation body and complete the necessary requirements of the accreditation process. But there are two standards: ISO/IEC 17020 and ISO/IEC 17025. So the agency quickly needs to consider which requirements are most appropriate for them.
Who gets accredited to which standard?
ISO/IEC 17025 is the standard for testing and calibration laboratories and ISO/IEC 17020 is the standard for inspection agencies. Both standards have equal weight as international standards and neither one is better than the other. Each standard is designed to meet certain criteria, and depending upon the situation, one maybe more appropriate than the other. Since many agencies and companies have labs as well as crime scene units, these entities achieve accreditation to both standards. This can be done within a singular assessment thereby eliminating the overlapping requirements.
ISO/IEC 17025 and ISO/IEC 17020 both include very similar management system requirements based on ISO 9001:2008 (section 4 in ISO/IEC 17025 and clause 8 in ISO/IEC 17020). Beyond these ISO 9001-based requirements, the standards diverge significantly. ISO/IEC 17025 requirements are heavy with regard to measurement uncertainty, traceability, and analytical validation. ISO/IEC 17020 requirements, in contrast, focus more strongly on impartiality, independence, and confidentiality.
Both standards address best business practices as outlined in ISO 9001 as well as best scientific method practices. The scientific method is a body of techniques for investigating phenomena, acquiring new knowledge, and/or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry is commonly based on empirical or measurable evidence subject to specific principles of reasoning.
For forensics, ISO/IEC 17025 is designed for analytical testing laboratories. The standard focuses on measurement uncertainty, metrological traceability, and proficiency as is appropriate when it comes to use of analytical scientific instrumentation for the identification and quantitation of a material. ISO/IEC 17025 makes reference to accuracy, precision, traceability, measurement uncertainty, and method validation, such as using the USP nine steps or the International Conference on Harmonization (ICH). Because most testing labs conduct analytical testing, ISO/IEC 17025 is a good fit. Forensic entities engage in a wide range of multi-disciplines, however, and some of which are a good fit for ISO/IEC 17025 and some of which are not a good fit because they are not an analytical chemistry discipline.
In the past, accreditation bodies have accredited police forensic agencies to ISO/IEC 17025. Historically, many crime scene investigation and latent print analysis units were part of a traditional state or large-city crime laboratory. Forensics has evolved, however, and now many more police agencies are taking over these tasks that once fell squarely in the arena of the big crime laboratories. Because of this trend, some accreditation bodies now offer accreditation to ISO/IEC 17025 for the more traditional analytical testing crime laboratories and to ISO/IEC 17020 for police forensic agencies that perform such disciplines as crime scene investigations, latent print analysis, ten prints, foot and tire print examinations, firearms examinations, handwriting analysis, digital media, and anthropology.
The ANSI-ASQ National Accreditation Board (ANAB) launched its ISO/IEC 17020 program for police agencies in 2011 and accredited the first law enforcement agencies in the United States and the Americas to this standard.
ANAB’s ISO/IEC 17020 accreditation program for police forensic units is designed for agencies that do not conduct analytical scientific testing using instrumentation and equipment found in a traditional science lab. ISO/IEC 17020 was developed for inspection processes that are based on professional judgment rather than analytical chemistry. The definition of inspection is to examine closely, to test an individual activity against established standards for that activity, to make a comparison. Inspection involves examination, measurements, testing, and comparison of materials or items.
The Worcester Police Department is accredited by ANAB to both ISO/IEC 17025 and ISO/IEC 17020. Lt. David Grady from the Worcester Police Department Latent Print Unit and Crime Scene Unit says that both accreditations are important, but serve different forensic purposes:
“The Crime Scene Unit is responsible for processing crime scenes and collecting and preserving physical evidence. Processing includes functions such as documentation, reconstruction and evidence identification. When the CSU arrives at a scene of crime, they are essentially inspecting that scene for evidence, documenting the scene and the evidence within and then deciding how to best collect and package those items. They are using professional judgment, more than sophisticated equipment, to direct their inspection process. The ISO/IEC 17020 requirements, with its requirements pertaining to impartiality and independence, confidentiality, item selection and item handling, are the perfect fit for a crime scene unit.”
Inspection body accreditation involves assurance of technical competence and practices, in addition to good quality management practices. While there is some overlap between inspection and testing, an important difference is that many types of inspection involve professional judgment to determine acceptability against specific requirements.
To assist users of the standards, ISO/IEC 17020 includes definitions of the terms “inspection” and “inspector.” Inspection as defined in ISO/IEC 17020 applies to crime scene investigations and/or examination of forensic evidence. The term inspector applies to an examiner or analyst who uses professional judgment to examine or inspect evidence with the aim to determine if the comparison between items meets certain criteria. The term inspector also applies to an investigator who uses professional judgment to examine a crime scene with the aim to contribute to determining what, where, when, how, and why something happened and who was involved. Crime scene, latent prints, video analysis, photography, and firearms are all inspection types of inspection operations in which one compares against defined criteria or a specification and then draws conclusions based professional judgment.
The ISO/IEC 17020 accreditation program is for most police agencies that perform comparisons between a piece of evidence and a known specification (for example, an unknown print against a suspect’s print) and then make a professional judgment as to whether the two items are similar or not.
Forensic agencies are encouraged to pursue the benefits of accreditation, but they should always consider carefully which standard best fits their specific needs. When one uses professional judgment to draw conclusions based on such comparisons, then ISO/IEC 17020 may be the more appropriate standard for accreditation. When one uses analytical instrumentation to generate analytical data that is used to determine the identity of an item, then ISO/IEC 17025 may be the more appropriate standard.
Pat Bencivenga is the Accreditation Manager for Inspection and Forensic Science at the ANSI-ASQ National Accreditation Board (ANAB). She has worked in forensics for more than 20 years as a Crime Laboratory Analyst, CODIS FBI DNA Administrator, and Forensic Technologist Supervisor. firstname.lastname@example.org