In the United States alone, over 50% of murders in 2020 went unsolved[1]. Homicide clearance rates have steadily declined since the 1960s, leaving nearly 346,000 cases of homicide and non-negligent manslaughter unresolved between 1965 and 2023[2]. With more and more advanced technologies at our disposal, it is expected that we are able to leverage those tools to improve these numbers. Yet, technology alone is not enough—the integrity and precision of every Crime Scene Investigator (CSI) remains irreplaceable.

This field guide is designed to support CSIs in the complex and high-stakes process of scene investigation. Your role is critical. Every detail matters. Every piece of evidence must be collected, documented, and preserved with the utmost care and integrity. Crime Scene Investigation is a demanding discipline.

This guide consolidates insights from a diverse group of investigators, researchers, crime scene investigators, and educators. It encompasses methods ranging from advanced technological approaches to cost-effective solutions, recognizing the varied resources available to different agencies. I hope this guide serves as a valuable tool in the field, makes a significant contribution to ongoing investigations, and helps shape future investigative practices through the experiences of those who have preceded us.

[1] Schilke, Rachel. "Half of US Homicides Go Unsolved, Ranking Last among Western Nations." Washington Examiner, 6 Mar. 2023. https://www.washingtonexaminer.com/news/2576215/half-of-us-homicides-go-unsolved-ranking-last-among-western-nations/

[2] Murder Accountability Project. “Murder Accountability Project.” Murder Data, www.murderdata.org.