In 2021, the Maryland Department of Health and the state police were confronting a crisis: Fatal drug overdoses in the state were at an all-time high, and authorities didn’t know why. There was a general sense that it had something to do with changes in the supply of illicit drugs—and specifically of the synthetic opioid fentanyl, which has caused overdose deaths in the US to roughly double over the past decade, to more than 100,000 per year. 

But Maryland officials were flying blind when it came to understanding these fluctuations in anything close to real time. The US Drug Enforcement Administration reported on the purity of drugs recovered in enforcement operations, but the DEA’s data offered limited detail and typically came back six to nine months after the seizures. By then, the actual drugs on the street had morphed many times over. Part of the investigative challenge was that fentanyl can be some 50 times more potent than heroin, and inhaling even a small amount can be deadly. This made conventional methods of analysis, which required handling the contents of drug packages directly, incredibly risky. 

There, a research chemist named Ed Sisco and his team had developed methods for detecting trace amounts of drugs, explosives, and other dangerous materials—techniques that could protect law enforcement officials and others who had to collect these samples. Essentially, Sisco’s lab had fine-tuned a technology called DART (for “direct analysis in real time”) mass spectrometry—which the US Transportation Security Administration uses to test for explosives by swiping your hand—to enable the detection of even tiny traces of chemicals collected from an investigation site. This meant that nobody had to open a bag or handle unidentified powders; a usable residue sample could be obtained by simply swiping the outside of the bag.  

Sisco realized that first responders or volunteers at needle exchange sites could use these same methods to safely collect drug residue from bags, drug paraphernalia, or used test strips—which also meant they would no longer need to wait for law enforcement to seize drugs for...