Determining how diluted bloodstains were derived: Inferring distinctive characteristics and formulating a guideline. (September 2019)

• Record Type: Journal Article
• Authors: van den Berge, M.; de Vries, F.G.; van der Scheer, M.; Sijen, T.; Meijrink, L.
• Is Part Of: Forensic science international. Volume 302(2019)
• Publication Date: 2019-09
• Subjects: Forensic science -- Bloodstain pattern analysis -- Diluted bloodstains -- Derivation -- Textile -- Coffee ring; Medical jurisprudence -- Periodicals; Chemistry, Forensic -- Periodicals; Forensic Medicine -- Periodicals; Médecine légale -- Périodiques; Chimie légale -- Périodiques; Gerechtelijke geneeskunde; Gerechtelijke chemie; Gerechtelijke psychiatrie; Chemistry, Forensic; Medical jurisprudence; Electronic journals; Periodicals; Electronic journals; 614.1
• DOI: 10.1016/j.forsciint.2019.109918
• Languages: English
• ISSNs: 0379-0738

Abstract

Highlights: Characteristics can determine the derivation of diluted bloodstains. Was blood deposited on a moist surface or did a bloodstain get moistened afterwards. A guideline aids in distinguishing how diluted bloodstains were derived. The guideline applies to diluted bloodstains on a range of textile types. The guideline helps to infer the actions that took place at a crime scene. Abstract: In forensic settings, diluted bloodstains are regularly encountered for example when bloodstains are mixed with tap-/rainwater, after deliberate cleaning attempts, or when blood is dropped on a wet surface such as a towel. Such diluted bloodstain scenarios can be subdivided into sequences of events in which a blood drop was either (1) readily diluted (a mixture of blood and water is deposited); (2) deposited on a surface that was readily moistened (first water, then blood) or (3) deposited and subsequently moistened (first blood, then water). Current bloodstain pattern analysis (BPA) lacks data and tools to distinguish these three ways of derivation of a diluted bloodstain that vary in the sequence of deposition of blood and water on textile. In this study, 880 bloodstains were examined for characteristics that can be used to determine the derivation of diluted bloodstains. A guideline to assist BPA-analysts in interpreting diluted bloodstains was extracted. The added value of this guideline was confirmed by conducting two surveys: one survey with and one without the guideline. A third survey confirmed that the characteristics also function on a broader range of textile types that have different weave and knit styles. This guideline can aid BPA-experts to determine, in an objective way, how diluted bloodstains derived which can aid in determining which activities took place at a crime scene.