An Experimental Study Of The Forensic Luminol Test For Detection Of Bloodstains

Katherine Kilgore

School Name

Governor's School for Science and Math

Grade Level

12th Grade

Presentation Topic

Chemistry

Presentation Type

Mentored

Mentor

Mentor: Dr. Morgan; Department of Chemistry and Biochemistry, University of South Carolina

Abstract

Bluestar® is a new latent blood detection reagent used by criminologists as a presumptive test for blood at crime scenes. It is a patented formula of luminol, which has been used for over 60 years. There have been no reproducible experiments done in a controlled setting to find the limit of detection (LOD). LODs previously reported range from 1:100 – 1:5,000,000 dilute. Furthermore, published studies have not explored the relationship between bloodstain concentration and chemiluminescent intensity. Not knowing the detection agent potential is a problem in investigations because blood evidence could be dismissed or not detected. We implemented stain barriers and measured the chemiluminescent responses of different bloodstain dilutions on cotton swatches using a camera and program which quantify data from photos. This experimental design renders a reproducible way to find an accurate limit of detection and proves a linear relationship between bloodstain dilution and chemiluminescent response. A limit of detection for the Bluestar® response to bloodstains on Fruit of the Loom cotton t-shirts was found to be 1:101,384 dilute using a calibration curve consisting of triplicate bloodstains 1:5,000 - 1:16,666 and blanks. These results help forensic criminologists know to look for dilute bloodstains, and will help less evidence be overlooked or dismissed.

Location

Owens 101

Start Date

4-16-2016 9:45 AM

COinS
 
Apr 16th, 9:45 AM

An Experimental Study Of The Forensic Luminol Test For Detection Of Bloodstains

Owens 101

Bluestar® is a new latent blood detection reagent used by criminologists as a presumptive test for blood at crime scenes. It is a patented formula of luminol, which has been used for over 60 years. There have been no reproducible experiments done in a controlled setting to find the limit of detection (LOD). LODs previously reported range from 1:100 – 1:5,000,000 dilute. Furthermore, published studies have not explored the relationship between bloodstain concentration and chemiluminescent intensity. Not knowing the detection agent potential is a problem in investigations because blood evidence could be dismissed or not detected. We implemented stain barriers and measured the chemiluminescent responses of different bloodstain dilutions on cotton swatches using a camera and program which quantify data from photos. This experimental design renders a reproducible way to find an accurate limit of detection and proves a linear relationship between bloodstain dilution and chemiluminescent response. A limit of detection for the Bluestar® response to bloodstains on Fruit of the Loom cotton t-shirts was found to be 1:101,384 dilute using a calibration curve consisting of triplicate bloodstains 1:5,000 - 1:16,666 and blanks. These results help forensic criminologists know to look for dilute bloodstains, and will help less evidence be overlooked or dismissed.