Facts about bloodstain pattern analysis

Originally appearing in the Georgia State Division of the International Association for Identification (Q2 2025), this article examines how cognitive bias can distort crime scene investigation and bloodstain pattern analysis. Drawing on real case experience, it explains confirmation and desirability bias, the bias blind spot, and the Dunning-Kruger effect. It also outlines practical safeguards—using the scientific method, seeking blind peer review, challenging one’s own conclusions, and slowing decision-making under pressure—to keep evidence ahead of assumptions and improve investigative accuracy.

Death investigation sits at the intersection of science, law, and human perception. From determining cause and manner of death to recognizing how bias can shape conclusions, investigators must balance evidence with objectivity. This article explores how forensic professionals reach their opinions, the dangers of confirmation bias, and why every death scene demands an open, evidence-driven mind.