Speeding Up the Wheels of Justice: How NIST Resources Can Help Crime Labs Work Faster

Unlike what you may see on TV or in the movies, forensic analysis of crime evidence takes a long time. And understaffed forensic laboratories around the country often have huge backlogs of evidence to process. The methods typically used to analyze these samples can take tens of minutes to complete, at minimum.

That may not sound like much. But multiply this by the hundreds or thousands of samples a forensic laboratory needs to analyze. This means cases take longer to prosecute, and the justice system moves more slowly than it should.

Science of Crime Scene Analysis

The first step in analyzing evidence typically involves the analyst looking at a sample in a way that gives them broad chemical information about the sample's contents. We call this a screening technique. Once the analyst has completed that step, they will use other tools or methods to get more detailed information.

Screening is an important part of the analyst's work, but these approaches don't all provide the level of detail the analyst needs quickly enough.

Luckily, companies are inventing new screening tools that work faster and provide higher levels of detail.

But when a forensic laboratory gets a new instrument, the staff has to check it very thoroughly through a series of procedures and experiments, called validation. Validation demonstrates that the instrument can analyze evidence with the required precision and accuracy, among other criteria. This is important because a forensic analyst needs to not only trust that the results of an analysis are correct but also be able to testify to their accuracy in court.

So, as forensic labs begin to use new equipment and methods, analysts need to validate these instruments. However, there are currently no prescribed steps specific to each analytical approach that can be followed to quickly and easily do this. Documenting validation processes often takes analysts months to complete, taking analysts away from their casework.

What does this evidence analysis process look like in practice in a forensic laboratory?

Analysts use an approach called gas chromatography-mass spectrometry, or GC-MS, to analyze most evidence samples, such as seized drugs and fire debris. Gas chromatography separates a sample into its different components. Mass spectrometry identifies and detects individual compounds using a unique chemical signature. So, if you're looking at a sample made up of multiple illegal drugs, for example, gas chromatography would separate the different drugs in the sample. Mass spectrometry would tell you what the individual drugs are in that sample.

NIST researcher Briana Capistran prepares drug samples to be analyzed.

GC-MS is the gold standard in forensics, but it also takes a lot of time - time many analysts simply don't have.

Many labs are now using a faster version of this system, called rapid GC-MS. It's not as precise, but it does a great job of screening samples, so the analysts can better understand the sample's contents. Potentially, the analyst can save the full GC-MS for samples that really require it. That's another time saver - possibly cutting analysis time from 20 minutes down to one or two minutes per sample.

Helping Labs Validate Their New Equipment

As a research chemist who has used this rapid version of GC-MS for the last several years, I developed a comprehensive instruction guide for rapid GC-MS validation processes that analysts can use in their own efforts. I tailored this guide to two forensic applications: seized drug screening and fire debris screening. While these samples might not look similar, both contain compounds that rapid GC-MS analyzes and detects. These samples are also some of the most common types of evidence received in a forensic laboratory.

I designed a validation process for both applications and documented it from start to finish. This free resource provides information on the materials the analyst would need to purchase, what analyses to perform on what days, and what data to gather. Accompanying spreadsheets have automated calculations built in. So, just by entering the specified data, an analyst can see almost immediately if the instrument is validated or not.

In the lab, Briana Capistran uses rapid gas chromatography-mass spectrometry (GC-MS) to analyze a drug sample. Gas chromatography separates different drugs in a sample, and mass spectrometry tells you what individual drugs are in the sample.

My goal was to do all that behind-the-scenes work so an analyst in a forensic laboratory could jump right into the validation procedure. All the analyst has to do is download an information package and follow the instructions.

This information package is so detailed because I've done this work myself. I validated NIST's own rapid GC-MS system and documented each step of the process. This will help our team serve as a resource for analysts who may have questions as they go through the process themselves.

The toolis new, and we are very eager to receive feedback. We hope to create more of these tools in the future tofacilitate this critical science.

Time Saved Will Help the Justice System

With the persistence of the opioid epidemic nationwide and the rising number of arson cases over the last few years, forensic analysts' chemistry-related workload is only increasing.

Backlogs continue to be a major issue, especially in the seized drug field. One of the reasons for this is the influx of drugs designed to have similar chemical structures and effects to illegal drugs, known as designer drugs. These drugs are made to circumvent the legal system, but they often still wind up in samples with illegal drugs.

While using new techniques like rapid GC-MS could improve overall analysis times, the time required to develop specific validation protocols can deter a lab from investing in these systems. That's where NIST researchers can help. Our resources can help get new tools up and running in a forensic laboratory. This means samples can be analyzed quickly, and hopefully, criminal cases can proceed faster.

Solving Real-Life Mysteries

From a young age, I've loved science and problem-solving. When I was applying to college, I knew I wanted to study applied science, but I wasn't sure exactly what.

As an avid reader of all things mysterious and investigative, I wound up studying forensic science, which was still a very new major at the time. I went on to get my master's degree in forensic science and a Ph.D. in chemistry because Ph.D. programs in forensic science weren't as common at the time.

Toward the end of my graduate schooling, my master's degree adviser introduced me to NIST research chemist Edward Sisco. I started with NIST as a postdoctoral researcher in 2021 and have since continued as a research chemist.

My postdoctoral work focused on debris analysis in fire investigations. I researched new approaches for screening fire debris samples and started working with the rapid GC-MS system.

Briana Capistran gets information on the drug sample about a minute after she placed the sample into the machine that analyzes it.

Having the flexibility and freedom to pursue the research I am passionate about was one of the best parts of my postdoc experience. I realized how much of an impact NIST research can have on the forensic community and the general public. Knowing that I could make a difference by helping forensic chemists do their jobs more effectively motivated me to continue my work at NIST.

Now, my research involves drug analysis in addition to fire debris. I've done some impactful projects in both spaces. I've worked to improve analytical methods for drug analysis and researched the best ways to prepare fire debris samples for analysis. While each focuses on a different type of evidence, all of the same chemistry principles apply and can be transferred from one sample to the next.

What I love the most about working in this field is its problem-solving roots and real-world impact. I fell in love with forensic science because it's one of the most applied versions of chemistry.

At its core, chemistry gives us the foundational pieces of knowledge to answer bigger questions. Forensic chemistry applies that knowledge to solve important and time-sensitive problems. It enables me to see how the research I do on a daily basis can be directly used to help others. As a community, we're using scientific knowledge to positively impact people everywhere and, hopefully, keep people safer.

Looking Ahead to New Challenges in the Forensic Field

I'm looking forward to continuing in this career field and applying my knowledge to forensic science as the discipline continues to grow and change.

One of the challenges in forensic science is that it can be quite subjective. Calls to improve objectivity in the field have sparked significant advancements over the last decade and more.

While drug analysis has progressed greatly in this time, some fields, like fire debris analysis, still rely on visual examinations to identify sample contents. Unfortunately, these visual judgment calls can affect analyst conclusions due to human bias. However, scientists at NIST and other institutions are researching ways to make these processes more objective.

The stakes of forensic science work are extremely high. Our work in this field has the potential to impact many people's lives, including whether a victim's family gets justice or an innocent suspect is set free or imprisoned.

Forensic science is, at its core, interdisciplinary -requiring the knowledge and expertise from professionals of so many disciplines. Knowing that I can play a role, however big or small, in progressing the field is my motivation for the work I do each and every day.

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