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Black Box Evaluation of Bloodstain Pattern Analysis Conclusions

NCJ Number
304645
Author(s)
R. Austin Hicklin; Kevin R. Winer; Paul E. Kish; Connie L. Parks; William Chapman; Kensley Dunagan; Nicole Richetelli; Eric G. Epstein; Madeline A. Ausdemore; Thomas A. Busey
Date Published
March 2021
Length
122 pages
Annotation

This is the Final Technical Research Report of the investigation of conclusions made by 75 practicing bloodstain pattern analysts on 193 bloodstain patterns selected to be broadly representative of operational casework, resulting in 33,005 responses from 27,038 classification prompts and 5,967 questions.

 

Abstract

The project also collected 1,760 short test summary conclusions. On prompts for which the cause of the depicted bloodstains was known, 11.2 percent of responses were erroneous (calculated on responses from 11,634 classification prompts and 2,163 questions). The project also collected 1,760 short text summary conclusions. On prompts for which the cause of the depicted bloodstain was known, 11.2 percent of responses were erroneous (calculated on responses from 11,634 classification prompts and 2,163 questions). The results indicate limited reproducibility of conclusions; 7.8 percent of responses contradicted other analysts. Both semantic differences and contradictory interpretations contributed to errors and disagreements, which could have a significant impact in actual casework. 31 tables and 43 references

Date Published: March 1, 2021