Bloodstain pattern analysis (BPA) is a forensic science discipline that examines bloodstain patterns at crime scenes to reconstruct the events that caused the bloodshed

Under a Cooperative Agreement awarded by the National Institute of Standards and Technology (NIST) Measurement and Engineering Research and Standards program (CFDA 11.609), Noblis, Inc. will conduct an empirical study on bloodstain pattern analysis (BPA) classification accuracy and reproducibility. Obligated funding of $249,878.42 supports this two-year research effort (January 1, 2026 – December 31, 2027), to be performed in Reston, Virginia. The study will engage qualified BPA analysts to evaluate high-resolution bloodstain images using established BPA process maps, with the goal of identifying where, when, and why errors and disagreements occur in classification determinations.

The primary deliverable is a final research report containing empirical data and findings addressing four key research questions regarding BPA process map effectiveness, analyst observations and classification methods, consistency in analyst observations, and factors explaining errors or disagreements. Results and recommendations will inform standards development, training enhancements, and methodology improvements in bloodstain pattern analysis, with findings intended for use by standards development groups, policymakers, law enforcement agencies, and the forensic science community to strengthen the scientific foundations of this forensic discipline.

Activities

The applicant will conduct an empirical study where qualified BPA analysts evaluate assigned high-resolution bloodstain images using the BPA process map and analyze the data to determine where and why disagreements and errors occur. Findings and recommendations will be published in a final report.

Expected outcomes

In addition to empirical data on when, how, and why errors and disagreements occur in BPA classifications, the proposed study will address four research questions: 1) how effective is the BPA process map in capturing BPA analysts observations and guiding them in making conclusions?2) what observations and features do BPA analysts use to make specific classifications, and how do they delineate between similar classifications?3) what is the extent of consistency and variability in observations made by BPA analysts? 4) to what extent can errors and/or disagreements be explained by differences in observations versus differences in interpretations versus semantic differences?intended beneficiaries: these results are intended for use by standards groups, policy makers, and laboratory managers/technical leaders to improve methodology, standardization, and training. This proposed effort is expected to increase confidence in and the usefulness of forensic BPA results.

Subrecipient activities

The recipient does not intend to subaward funds.