PROVIDENCE, R.I. (WPRI) — State health officials on Friday disclosed an incident at a state lab that revealed cross-contamination of test samples, drawing into scrutiny at least 52 drug cases involving cocaine.

The disclosure came after the R.I. Department of Health held a routine quality assurance test at its Forensic Drug Chemistry Lab where scientists are blindly tested to determine how accurately they are testing different types of drug samples.

In one instance last fall, a lab scientist reported trace amount of cocaine that shouldn’t have been present, as the Health Department knew it wasn’t contained in that sample. They have determined the cocaine carried over from a previous sample, but the misstep nonetheless drew into question the accuracy of the scientist’s previous casework tied to all cocaine-related cases — triggering a review with the R.I. Attorney General’s Office.

“Although this issue arose during analysis of a quality assurance test case, not in relation to an actual criminal case, the [Health Department] is notifying the Rhode Island Attorney General’s Office of this issue,” State Health Lab Director Glen Gallagher wrote in a March 17 letter to the attorney general’s Narcotics and Violent Crime Unit.

The scientist worked on about 1,313 law enforcement cases between June 2021 and November 2022, according to the letter. Health officials ruled out about 549 of those cases because they didn’t involve cocaine. Another 436 were discounted because they involved such high volumes of cocaine that cross-contamination wasn’t likely.

For 52 cases, where lower-levels of cocaine were present, health officials said they deserve closer scrutiny because of the cross-contamination issue.

“If evidence on these cases remains and can be retrieved from law enforcement agencies for re-testing, re-testing will be done immediately,” Gallagher wrote.

Another 263 cases involving less than 10 grams of controlled substances are also still under review, as Gallagher said they may or may not involve cocaine.

Health officials did not make a final determination about how the cross-contamination happened, although they said “potential factors” could be tied to the way cocaine transmits through the air or the sensitivity of their equipment.

“Unlike other powdered substances, cocaine’s fine particles can get into the air and settle on surfaces,” Gallagher wrote. “Additionally, the instruments we now use to identify controlled substances are much more sensitive in order to detect fentanyl and other opioids. Even very minute amounts of cocaine can be detected by this newer instrumentation.”

The revelation could create a headache for prosecutors, who use drug lab evidence to try cases and secure convictions. One the other hand, the misstep could result in a potential win for defense attorneys, who might use the erroneous testing as an argument to get criminal charges dropped.

After receiving the review from the Health Department, Attorney General Peter Neronha spokesperson Brian Hodge said they “acted immediately” to understand the potential scope of the issue and worked to see what criminal cases may have been affected.

“As a result of the notice we received from the Lab, we have requested that all affected exhibits be retested,” Hodge said in a statement. “We also understand that the Lab will expedite the retesting of exhibits.”

He also said the office has reached out to the state’s Public Defender’s Office, along with other law enforcement, and it doesn’t appear any defendant currently being held or serving time at the state prison is being incarcerated “solely based on charges involving cocaine.”

Health officials said the scientist, who wasn’t named and had never had any previous reported issues of false detections of any substance, has been removed from testing drug cases involving cocaine until they can be retrained.

“Following our initial action, we will continue our work to evaluate the scope and impact of this issue, and expeditiously work with stakeholders to ensure that no individual’s rights have been violated,” Hodge said.

Eli Sherman ( is a Target 12 investigative reporter for 12 News. Connect with him on Twitter and on Facebook.