Targeted-Ion Mass Spectrometry for the Identification of Forensically Relevant Biological Fluids and Samples from Sexual Assault Evidence

• NCJ Number: 309941
• Author(s): Heather Erin McKiernan
• Date Published: 2019
• Length: 180 pages
• Grant Number(s): 2015-R2-CX-0024
• Agencies: NIJ-Sponsored
• Publication Type: Thesis/Dissertation; Research (Applied/Empirical)
• Award: Improving Seminal Fluid Detection Sensitivity in Extended Post-Coital Intervals by QQQ Mass Spectrometry

Annotation

This study employs targeted-ion mass spectrometry for the identification of forensically relevant biological fluids and samples from sexual assault evidence.

Abstract

In this paper, researchers assessed the utility of targeted-ion mass spectrometry to identify forensically relevant biological fluids and samples from sexual assault evidence. Through the results, researchers demonstrated the prevalence of false-positive results associated with antibody-based serological methods, developed and validated a multiplex targeted-ion mass spectrometry-based assay for the identification of six forensically relevant biological fluids, demonstrated improved sensitivity and specificity of mass-spectrometry based body fluid identification as compared to traditional techniques, developed a modified assay for seminal fluid compatible with sexual assault kit evidence, and evaluated the relationship between quantitative levels of target seminal fluid peptides and the ability to generate Y-STR profiles. These results provide the forensic and criminal justice communities with a powerful tool to aid in the criminal investigation of violent crimes. Forensic practitioners have long sought efficient and reliable means for identifying those samples that are best suited for successful genetic profiling. A sensitive and accurate technology for the confirmatory identification of biological fluids would greatly bolster the weight of serological evidence presented in court and assist with more informed sample prioritization. A particularly promising approach combines high-specificity protein biomarkers with a target-ion mass spectrometry. Applying absolute quantitation of protein targets in the biomarker panel will enable forensic practitioners to make fuller use of serological information in their decision making on downstream analyses in order to improve the successful analysis of challenging sexual assault samples.