In the realm of forensic science, particularly within the domain of latent print examinations, the discussion around error rates and the efficacy of proficiency tests is both critical and complex. The paper titled "Error rates and proficiency tests in the fingerprint domain: A matter of perspective and conceptualization" by Aldo Mattei and Francesco Zampa delves into these intricacies, offering a nuanced exploration of the challenges and considerations inherent in measuring error rates and designing proficiency tests (PTs) and collaborative exercises (CEs) for fingerprint analysts.

The Importance of Realistic Proficiency Tests

One of the paper's key arguments is the necessity for proficiency tests to mimic the real-world conditions that fingerprint examiners face. Contrary to the belief that reference prints used in PTs should always be of the highest quality, the authors argue that in reality, examiners often deal with prints of varying quality and completeness, such as post-mortem prints. Therefore, to truly assess an examiner's proficiency, PTs must include reference material that reflects this heterogeneity.

The Role of Black-Box Studies

The paper emphasizes the significance of black-box studies in establishing the foundational validity of fingerprint analysis methods. These studies are crucial for assessing the validity and reliability of the subjective methods used in latent print examinations. The authors highlight the need for additional empirical studies to estimate error rates for latent prints of varying quality and completeness, using well-defined measures.

Proficiency Testing: Beyond Skill Assessment

Mattei and Zampa challenge the conventional view of proficiency testing as merely a means to test an examiner's skills. They argue that PTs serve multiple purposes, including demonstrating a laboratory's ability to achieve consistent results and authenticating the entire analytical process. The paper criticizes the current standards of proficiency testing for not adequately representing real-world casework and calls for the design of PTs that evaluate specific skills relevant to daily forensic activities.

The Challenge of Measuring Error Rates

The paper discusses the different scenarios of black-box studies and the perspectives from which error rates should be observed. It underscores the distinction between evaluating the accuracy of individual examiners and the likelihood of incorrect associations in criminal trials, highlighting the need for PTs and CEs to be conceptualized with these different perspectives in mind.

Towards Improved Proficiency Testing

The authors advocate for proficiency tests that are challenging and representative of the complexities of casework. They call for the forensic science community to support the participation in challenging PTs/CEs, allowing examiners adequate time to complete the tests. Additionally, the paper suggests the implementation of blind proficiency tests to provide a more accurate measure of forensic science providers' performance, though it acknowledges the practical difficulties of such an approach.


The paper by Mattei and Zampa offers a comprehensive analysis of the issues surrounding error rates and proficiency testing in the fingerprint domain. It calls for a reevaluation of how proficiency tests are designed and conducted, emphasizing the need for tests that accurately reflect the realities of forensic work. By addressing these challenges, the forensic science community can enhance the reliability of latent print examinations and strengthen the overall integrity of forensic evidence in the judicial system.

This exploration into the complexities of error rates and proficiency testing underscores the ongoing need for research, dialogue, and innovation within the field of forensic science. As we strive to improve the accuracy and reliability of latent print examinations, it is crucial that we continue to critically assess our methods and practices, always with the goal of advancing justice and truth.



Mattei, A., & Zampa, F. (2023). Error rates and proficiency tests in the fingerprint domain: A matter of perspective and conceptualization.