In June 2025, Colorado Governor Jared Polis (D) signed a bill that established a working group focused on the impact of colorimetric drug tests, the rapid-result field kits that law enforcement and corrections officers across the country use to check unknown substances for the presence of drugs.
It was the first legislative gesture toward addressing the crisis of colorimetric testing, which an explosive 2024 report identified as “one of the largest, if not the largest, known contributing factor to wrongful arrests and convictions in the United States.” The notoriously false positive-prone tests lead to an estimated 30,000 people wrongfully arrested each year.
On January 14, legislators introduced House Bill 26-1020, which based on the working group’s recommendations would reform two critical processes in which colorimetric tests are used. First, instead of arresting people for Level 1 misdemeanor drug possession (DM1) based on the test results, law enforcement officers would be required to release them on their own recognizance. They’d be required to sign an agreement to reappear at a later date, but the bill states explicitly that this summons is not an arrest warrant. Under current Colorado law, DM1 carries a mandatory minimum sentence of six months in county jail and a maximum sentence of 18 months, and/or fines between $500 and $5,000.
Second, in order to accept a guilty plea for Level 4 felony drug possession (DF4) or any less-serious possession charges involving colorimetric testing, a judge would first have to advise the defendant of the following: that the tests are subject to false positives; that the results are inadmissible in court; and that they have the right to change their plea and request that the results be confirmed by an accredited lab.
“[P]eople regularly plead guilty to drug possession offenses absent laboratory confirmation because they cannot afford to remain in custody awaiting a laboratory test or cannot afford a lengthy courtroom battle,” the working group stated in its recommendations. “Consequently, the plea and its collateral consequences burden the person indefinitely.”
Portable laboratory-grade equipment has an upfront cost, but there’s a pretty good chance colorimetric testing costs more each year.
Colorimetric field testing, which the new bill defines as “a presumptive screening method performed outside of a forensic laboratory by someone other than a forensic chemist,” uses chemical reagents that change color upon contact with different banned drugs—along with lots of not-banned substances like soap or chocolate, which further complicates results that were subjective and easily misinterpreted to begin with. The tests are designed to provide informal results pending confirmation at a forensics lab, and though not admissible in court have become rampant in extrajudicial processes, namely plea deals and prison disciplinary sanctions.
In 2025, the working group surveyed the prosecutors of each of Colorado’s 23 judicial districts; only four responded, but they all agreed that test results are only confirmed at a lab when a case goes to trial—which can take years. Almost every drug possession case ends in a plea deal.
“This explains why the issue of colorimetric field drug test false positives has gone unnoticed for so long in Colorado and throughout the United States,” the working group continued in its recommendations. “In the absence of laboratory confirmatory testing, the incidence of false positives is largely invisible.”
The only other state that currently appears to be considering similar legislation is North Carolina. That bill has not moved from the House Committee on Rules, Calendar and Operations since shortly after its introduction in April 2025.
One of the prosecutors reported that their district conducted most field testing using a Raman spectrometer—a portable electronic drug-testing device that’s far more accurate than the colorimetric kits. The working group noted that this model could potentially be adopted elsewhere as an alternative, “although the device can be costly to purchase.”
A January 19 fiscal note for HB 26-1020 found that its impact on the budget would be $0, which makes any bill more attractive to legislators. But while it is true that portable laboratory-grade equipment has an upfront cost, from an annual budget perspective there’s a pretty good chance that colorimetric testing costs more. Each kit runs about $3. A 2018 Department of Justice report on the applicability of portable devices for presumptive drug-testing contexts suggested that in a large city, police are using around 10,000 colorimetric kits a year. You could probably buy two Raman spectrometers with $30,000. The Colorado Department of Corrections (CDOC) reportedly has two MX908 devices, which are even more expensive, but still mostly uses the colorimetric kits.
The Colorado Department of Corrections false-positive rate was about 33 percent.
In addition to most of the state’s top prosecutors, the working group reported that its inquiries were ignored by the rest of the law enforcement field and most of the test kit manufacturers. But the group did receive feedback from CDOC, where the false-positive rate for colorimetric test results is about 33 percent. Because prisoners are sanctioned according to internal DOC policies, rather than a court of law, it’s rare that the presumptive results get sent out for lab confirmation.
In prisons around the country, unconfirmed false positives are the justification for transfers to higher-security housing, loss of privileges like commissary and visitation, and loss of “earned time” or other pathways to early release. Filter has previously reported on presumptive testing by the Washington State Department of Corrections that continued to shape policy amid a class-action lawsuit. In Massachusetts, where a 2021 class-action lawsuit revealed the state’s prison system’s false-positive rate was about 38 percent, the department of corrections (MDOC) reportedly shifted away from basing any internal sanctions on colorimetric test results. According to the Colorado working group recommendations, the Office of the Inspector General was supportive of doing something similar.
“Although CDOC’s rate of 32.9 percent is very close to [MDOC’s], CDOC officials informed the Working Group that it did not find this solution viable due to the long wait for confirmatory testing,” the group continued. “CDOC prison operations staff [also] expressed their need to combat the entry of drugs into prisons.”
The 2025 bill that established the working group, and thus the basis for the new bill filed January 14, stated that the group’s recommendations would be “necessary to improve judicial system outcomes, including preventing wrongful convictions, coercive plea agreements, and negative correctional outcomes.” The new bill only includes two out of the three because after CDOC objected, the working group decided that “due to the complexities of this issue” it was better to not make any recommendations for carceral settings at all.
Image via NASA Technical Reports Server