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Advancing Research in Trace Evidence

“We believe in transforming ideas into research and research into meaningful solutions for our law enforcement, the criminal justice system, homeland security, and public safety.”

Explore Our Research

Our research focuses on building capacity by developing innovative methods and interpretation models for more effective decision-making processes. Glass, paint, textiles, polymers, gunshot residues, counterfeits, and questioned documents are among the materials of interest in our team.

Dr. Trejos is an Associate Professor of the Department of Forensic and Investigative Sciences at West Virginia University, where she teaches forensic courses for the undergraduate, master's, and doctorate programs. Dr. Trejos believes in learning by doing and creating connections with real-world scenarios by bringing her forensic practitioner and law enforcement expertise to the classroom. Dr. Trejos' long-term research goal is to develop methods that enhance trace evidence's reliability and efficiency, providing valuable data to the criminal justice system and streamlined processes. Her research group focuses on building capacity and applying emerging methods to improve data quality and data usage. Dr. Trejos's main research includes applying statistics to evidence interpretation and the discovery of chemical signatures of forensic materials by spectrochemical methods, such as SEM-EDS, ICP-MS, Laser Ablation ICP-MS u-XRF, Laser-Induced Breakdown Spectroscopy, and Mass Spectrometry (GC-MS and LC-MS).  Glass, paints, polymers, inks, and gunshot residues are among the trace materials investigated in Dr. Trejos' laboratory. Dr. Trejos has received over $4 million in funding from the U.S. Department of Justice, the National Institute of Justice, the Department of Commerce, and the Department of State. Tatiana Trejos has authored 80 peer-reviewed scientific publications and book chapters in the field of forensic and analytical chemistry. Dr. Trejos has served as a program chair of scientific meetings and guest speaker at several venues worldwide. Dr. Trejos received the prestigious science and technology award "Clodomiro Picado Twight" from the Costa Rican National Academy of Sciences (2015), was listed on the Forensics Colleges' top 10 forensic chemistry professors and received the WVU Eberly College Outstanding Researcher Award (2020).

Tatiana has contributed to different scientific working groups. Tatiana is a member and technical contact of the ASTM E-30 committee and the NIST Chemistry/Instrumental Analysis Scientific Area Committee's (SAC's) Materials (Trace) Subcommittee within the Organization of Scientific Area Committees (OSAC).  Within the NIST-OSAC organization, she has served as chair of the Research and Glass Working Groups, a member of the Interpretation and the Physical Fits Groups, and an affiliate of the Gunshot Residue Subcommittee. Tatiana has served in two NIST Scientific and Technical Review Panels (STRPs) for physical fits and gunshot residue. Tatiana's contributions include drafting discipline-specific standard guidelines and testing methods, identifying research and development needs in trace evidence, designing and leading interlaboratory studies, and developing plans for training, disseminating, and implementing consensus-based methods. Dr. Trejos is a Director of the American Society of Trace Evidence Examiners (ASTEE).

Areas of Expertise:

  • Forensic Chemistry
  • Trace Evidence
  • GSR, Fire Debris, and Explosives
  • Questioned Documents and Drugs
  • Chemometrics
  • Quality Assurance
  • Spectroscopy
  • Mass Spectrometry
  • Elemental Analysis
  • Higher Education Teaching
  • Research Mentorship
  • Project Management

Funded Research:

  1. Strengthening Scientific Foundations for Advancing Best Practices in the Collection, Storage, Analysis, and Interpretation of Organic and Inorganic Gunshot Residues. (Jan 2024-December 2025). Award # 15PNIJ-23-GG-04218-SLFO. Luis Arroyo (PI), Tatiana Trejos (co-PI).
  2. DOS-INL- Strengthening the Technical-Scientific and Quality Control Framework of the Judicial System in Costa Rica: from Crime Scene to the Expert Opinion in Courtroom-Phase II, (Jan 2023- May 2025) Award # SINLEC20CA3120, Tatiana Trejos (PI) and Luis Arroyo (co-PI)
  3. NIJ- Assessing the reliability of modern µXRF technology for expanded impact on the forensic examination and interpretation of trace evidence. Award # 15PNIJ-22-GG-03571-SLFO, (Jan 2023-Dec 2024). Tatiana Trejos (PI)
  4. Department of Commerce. Procurement of Technology and Equipment to Respond to Opioid and Violence Epidemics in WV. Award # 60NANB22D204, (Oct 2022-Sep 2023). Tatiana Trejos (PI), Luis Arroyo (co-PI), Casper Venter (c0-PI)
  5. NIJ- Assessing the Strength of Trace Evidence Fracture Fits through a Comprehensive, Systematic and Quantifiable Approach. Award # 2020-DQ-BX-0012, (Jan 2021-Dec 2022) Tatiana Trejos (PI), Aldo Romero (co-PI)
  6. NIJ- Comprehensive Assessment of Novel Reference Materials and Analytical Methods for the Analysis and Interpretation of Organic and Inorganic Gunshot Residues, (Jan 2021-Dec 2022). Award # 2020-DQ-BX-0010, Luis Arroyo (PI) and Tatiana Trejos (co-PI)
  7. DOS-INL- Strengthening the Technical-Scientific and Quality Control Framework of the Judicial System in Costa Rica: from Crime Scene to the Expert Opinion in Courtroom, May 2020- May 2022) Award # SINLEC20CA3120, Tatiana Trejos (PI) and Luis Arroyo (co-PI)
  8. NIJ- Development of baseline survey of random presence of glass and paint for the interpretation of evidence in the US courts. Award # 2019-DU-BX-0015, (Jan 2020-Dec 2 class="mb-1"021) Tatiana Trejos (PI).
  9. NIJ- STEM Graduate Fellowship. Validation of a Single Instrument, Single Protocol for the Detection of the Inorganic and Organic Constituents of Firearm Discharge Residues. Award # 2019-R2-CX-044, (Jan 2020-Dec 2021). Tatiana Trejos (PI) and William Feeney (PhD Student Fellowship Recipient)
  10. WVU-PSCOR, Internal grant, seed program. Strengthening the Forensic Examination and Interpretation of Physical Fits. Tatiana Trejos (PI) and Aldo Romero (co-PI)
  11. NIJ- Fast Screening of Firearm Discharge Residues by Laser-based Spectrochemical Methods, Electrochemical Sensors, and Chemometrics. Award # 2018-DU-BX-0186, (Jan 2019-Dec 2020). Tatiana Trejos (PI) and Luis Arroyo (co-PI)
  12. NIJ- STEM Graduate Fellowship. Characterization of Modern Ammunition and Background Profiles: A Novel Approach and Probabilistic Interpretation of Inorganic Gunshot Residue. Award # 2018-R2-CX-009, (Jan 2019-Dec 2020). Tatiana Trejos (PI) and Korina Menking-Hoggatt (PhD Student Fellowship Recipient).
  13. WVU-PSCOR, Internal grant, seed program. Fast Screening and Interpretation of Firearm Discharge Residues by Laser-Based Spectrochemical Methods, Electrochemical Sensors and Chemometrics. Jan 2017. Tatiana Trejos (PI) and Luis Arroyo (co-PI)
  14. Subaward WVU-FIU. Characterization and comparison of tape evidence using elemental profiling methods and chemometric analyses.

Teaching:

  • FIS 696/796: Graduate Seminar
  • FIS 414/614: Advanced Trace Evidence (Lecture and Laboratory)
  • FIS 703: Research Design in Forensic Science
  • FIS 340/341: Forensic Chemical Analysis (Lecture and Laboratory)