A quantitative method for determining a representative detection limit of the forensic luminol test for latent bloodstains

Brianna M Cassidy; Zhenyu Lu; Jennifer P Martin; Shawna K Tazik; Katie W Kellogg; Stephanie A DeJong; Elle O Belliveau; Katherine E Kilgore; Samantha M Ervin; Mackenzie Meece-Rayle; Alyssa M Abraham; Michael L Myrick; Stephen L Morgan

doi:10.1016/j.forsciint.2017.06.031

A quantitative method for determining a representative detection limit of the forensic luminol test for latent bloodstains

Forensic Sci Int. 2017 Sep:278:396-403. doi: 10.1016/j.forsciint.2017.06.031. Epub 2017 Jul 5.

Authors

Affiliations

¹ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: cassidbm@email.sc.edu.
² Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: lu29@email.sc.edu.
³ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: marti567@email.sc.edu.
⁴ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: tazik@email.sc.edu.
⁵ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: witherka@gmail.com.
⁶ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: dejongs@email.sc.edu.
⁷ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: bellivea@email.sc.edu.
⁸ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: kek.kilgore@yahoo.com.
⁹ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: ervinsm@email.sc.edu.
¹⁰ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: meeceray@texas.edu.
¹¹ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: alyssaa@email.sc.edu.
¹² Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: myrick@mailbox.sc.edu.
¹³ Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA. Electronic address: morgansl@mailbox.sc.edu.

PMID: 28837893
DOI: 10.1016/j.forsciint.2017.06.031

Abstract

The luminol test has been used for over 60 years by forensic investigators for presumptive identification of blood and visualization of blood splatter patterns. Multiple studies have estimated the limit of detection (LD) for bloodstains when luminol is employed, with results ranging from 100× to 5,000,000× dilute. However, these studies typically have not identified and controlled important experimental variables which may affect the luminol LD for bloodstains. Without control of experimental parameters in the laboratory, variables which affect the potential of presumptive bloodstain test methods remain largely unknown, and comparisons required to establish new, more powerful detection methods are simply impossible. We have developed a quantitative method to determine the relationship between the amount of blood present and its reaction with luminol by measuring, under controlled conditions, the resulting chemiluminescent intensity with a video camera, combined with processing of the digital intensity data. The method resulted in an estimated LD for bloodstains on cotton fabric at ∼200,000× diluted blood with a specific luminol formulation. Although luminol is the focus of this study, the experimental protocol used could be modified to study effects of variables using other blood detection reagents.

Keywords: Blood; Bloodstain; Chemiluminescence; Experimental control; Limit of detection; Luminol.

MeSH terms

Blood Stains*
Forensic Medicine / methods
Humans
Indicators and Reagents
Limit of Detection
Luminescent Measurements*
Luminol*
Software
Video Recording

Substances

Indicators and Reagents
Luminol