Continuous Alcohol Monitoring Programs: ​

Challenges and Implications

Counterpoint Volume 8; Issue 4 - Article 5 (March 2025)

An article in the upcoming Mastery Skills II Course

Jan Semenoff, BA, EMA
​Forensic Criminalist

Article information:

Article - 1200 words (approximately 6-8 minutes)
This is Part 2 of a series of articles on Continuous Alcohol Monitoring programs. CLICK HERE for Part 1
​Continuous Alcohol Monitoring (CAM) programs are increasingly employed within the criminal justice system, particularly for individuals mandated to abstain from alcohol due to prior offences related to alcohol (ethanol) use, such as driving under the influence (DUI). These programs utilize technologies such as transdermal alcohol monitors to track alcohol consumption in real-time, or breath test devices that administer tests at random intervals, providing both individuals and legal authorities with data intended to ensure compliance. 
​However, numerous issues accompany these monitoring systems, including false positive readings, difficulties in interpreting the data presented, and concerns over device calibration and potential malfunctions. Understanding these challenges is crucial for defense attorneys advocating for their clients who are subjected to these measures. 

False Positive Readings and Their Implications

False positives are a significant concern for attorneys and their clients in continuous alcohol monitoring programs. Although transdermal devices are designed to provide accurate real-time assessments of transdermal alcohol concentration (TAC) through skin perspiration, they are not infallible. As well, the fuel cell-based breath test devices used in monitoring or ignition interlock systems can also be affected by substances other than ethanol.
​Research indicates that these devices can produce false positives due to environmental factors such as exposure to alcohol-containing substances, like hand sanitizers or perfumes, which can result in elevated readings without actual alcohol consumption (Karns‐Wright et al., 2018; Barnett et al., 2014; Dougherty et al., 2012). The conservative detection criteria established by some manufacturers aim to mitigate the risk of false positives, with studies reporting that the false-positive rates can be notably reduced under these strict guidelines (Barnett et al., 2014). 
​Attorneys should be prepared to challenge the reliability of these readings when they arise in court. Jurisprudence concerning these devices can be complex; therefore, understanding the nuances of the technology, including its sensitivity to various external factors, is essential for effective representation. Such legal strategies could involve scrutinizing the conditions under which the alcohol monitor was deployed and questioning the validity of readings obtained during instances of suspected false positives (Voas, 2010). 

Data Interpretation Challenges

​Interpretation of data presented by CAM systems is inherently complex and can lead to misunderstandings among judges, juries, and practitioners alike. The mathematical models used to convert transdermal alcohol concentration (TAC) data into estimates of BAC are not always straightforward, and discrepancies can arise between the two measures depending on a host of factors including individual physiological differences (Dougherty et al., 2015; Simons et al., 2015). For example, research indicates significant variances in TAC between genders, complicating the interpretation of results from a legal perspective (Hill‐Kapturczak et al., 2014). 
​Importantly, attorneys must recognize that while TAC monitoring provides continuous data streams on alcohol consumption, these figures do not necessarily equate to intoxication or even recent use. Transdermal systems measure alcohol diffusion through the skin, which can lag behind actual BAC changes, leading to potential misinterpretation of a client’s state at the time a reading was taken (Barnett et al., 2011; Hill‐Kapturczak et al., 2014). Therefore, it is imperative for attorneys to advocate for comprehensive evaluations of individual cases, emphasizing that raw monitoring data must be analyzed in the context of each individual's unique situation. 

Calibrations and Malfunctions: A Continuing Concern

​Beyond false positives and interpretative difficulties, frequent calibration and potential device malfunctions present significant challenges. Since they are based on simple fuel cell technology, CAM devices must be regularly calibrated to maintain both their accuracy and reliability. Various studies highlight that failure to conduct these calibrations could lead to erroneous data reporting, which can significantly impact a client's legal standing (Nishank, 2022; Jalal et al., 2016). Moreover, inherent technological issues—ranging from software glitches to sensor malfunctions—can yield missing or inaccurate readings, further complicating the already fraught landscape of alcohol monitoring in legal contexts. 
​Legal professionals need to possess a working knowledge of the specific devices used in their client’s monitoring, as understanding the strengths and weaknesses of these systems forms a critical component of their advocacy. For instance, knowing which models require more frequent recalibrations or are prone to certain types of malfunctions can empower attorneys to advocate for their clients’ rights effectively (Mathias et al., 2019; Calverley et al., 2020). 

Examining the CAM Case

​Given the numerous potential issues associated with Continuous Alcohol Monitoring programs, attorneys must adopt a strategic approach when handling cases involving these devices. Here are several key strategies:
  1. Scrutinize the Device's Calibration and Maintenance Logs: Obtain records to confirm that the CAM device was properly calibrated and maintained. Any discrepancies or lack of documentation should be noted and may be grounds for challenging the reliability of the evidence. Again, access to the hard dataset is essential. We need real numbers taken over time to properly analyze the reported readings.
  2. Question the Context of Readings: Examine the circumstances surrounding the alleged alcohol consumption. Were there environmental factors, skin conditions, or non-alcoholic products that could have influenced the readings? Presenting such evidence can cast doubt on the accuracy of the data.
  3. Challenge the Interpretation of Results: Emphasize that CAM device readings are not definitive proof of alcohol consumption. Educate the court or the jury on the difference between BAC measurements and readings obtained from CAM devices and question the appropriateness of using CAM data as sole evidence.
  4. Highlight Equipment Malfunctions: If there is any evidence or suspicion of device malfunction, work with an expert to investigate whether the device may have been faulty or malfunctioning at the time the readings were obtained.
  5. Expert Testimony: Consider consulting experts in toxicology, instrumentation, and the specific technology behind CAM devices. Expert testimony can help illuminate the complexities of CAM readings and potentially expose weaknesses in the prosecution's case.

Conclusion

​While continuous alcohol monitoring systems can serve valid purposes within the criminal justice framework, there are potential pitfalls that defense attorneys must be able to navigate. False positives, interpretation complexities, and calibration issues can significantly undermine the reliability of evidence derived from these devices. Therefore, defending clients subjected to continuous alcohol monitoring requires a nuanced understanding of these systems and a robust insistence on accuracy and fairness in the legal process. As more jurisdictions implement these programs, it is essential for legal professionals to advocate for transparency and rigor in the technology utilized, ensuring that justice remains equitable and precise. 

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For further study:

  1. Karns‐Wright et al. "The correspondence between transdermal alcohol monitoring and daily self-reported alcohol consumption" Addictive behaviors (2018) doi:10.1016/j.addbeh.2018.06.006.
    https://www.sciencedirect.com/science/article/abs/pii/S030646031830618X?via%3Dihub
  2. Barnett et al. "Predictors of detection of alcohol use episodes using a transdermal alcohol sensor." Experimental and clinical psychopharmacology (2014) doi:10.1037/a0034821. https://psycnet.apa.org/doiLanding?doi=10.1037%2Fa0034821
  3. Dougherty et al. "Comparing the detection of transdermal and breath alcohol concentrations during periods of alcohol consumption ranging from moderate drinking to binge drinking." Experimental and clinical psychopharmacology (2012) doi:10.1037/a0029021. https://psycnet.apa.org/doiLanding?doi=10.1037%2Fa0029021
  4. Voas "Monitoring Drinking" Transportation research record journal of the transportation research board (2010) doi:10.3141/2182-01. https://journals.sagepub.com/doi/10.3141/2182-01
  5. Dougherty et al. "The Potential Clinical Utility of Transdermal Alcohol Monitoring Data to Estimate the Number of Alcoholic Drinks Consumed" Addictive disorders & their treatment (2015) doi:10.1097/adt.0000000000000060. https://journals.lww.com/addictiondisorders/abstract/2015/09000/the_potential_clinical_utility_of_transdermal.2.aspx
  6. Simons et al. "Quantifying alcohol consumption: Self-report, transdermal assessment, and prediction of dependence symptoms" Addictive behaviors (2015) doi:10.1016/j.addbeh.2015.06.042. https://www.sciencedirect.com/science/article/abs/pii/S0306460315002403?via%3Dihub
  7. Hill‐Kapturczak et al. "Accounting for sex-related differences in the estimation of breath alcohol concentrations using transdermal alcohol monitoring" Psychopharmacology (2014) doi:10.1007/s00213-014-3644-9. 8. https://link.springer.com/article/10.1007/s00213-014-3644-9
  8. Barnett et al. "Contingency management for alcohol use reduction: A pilot study using a transdermal alcohol sensor" Drug and alcohol dependence (2011) doi:10.1016/j.drugalcdep.2011.04.023. https://www.sciencedirect.com/science/article/abs/pii/S0376871611002080?via%3Dihub
  9. Hill‐Kapturczak et al. "Do Variable Rates of Alcohol Drinking Alter the Ability to Use Transdermal Alcohol Monitors to Estimate Peak Breath Alcohol and Total Number of Drinks?" Alcoholism clinical and experimental research (2014) doi:10.1111/acer.12528. https://onlinelibrary.wiley.com/doi/10.1111/acer.12528
  10. Nishank "Peri-Operative Management of Patients with Continuous Alcohol Monitoring Devices: A Case Report and Review of Literature." Journal of anesthesia and anesthetic drugs (2022) doi:10.54289/jaad2200104. https://www.acquirepublications.org/Journal/Anesthesia/Articles/JAAD2200104
  11. Jalal et al. "Development and Characterization of Fuel Cell Sensor for Potential Transdermal Ethanol Sensing" Ecs transactions (2016) doi:10.1149/07231.0025ecst. https://iopscience.iop.org/article/10.1149/07231.0025ecst
  12. Mathias et al. "Estimating resource utilization demands in implementing statewide screening, brief intervention, and referral to treatment for alcohol-impaired drivers" Traffic injury prevention (2019) doi:10.1080/15389588.2018.1528500. https://www.tandfonline.com/doi/full/10.1080/15389588.2018.1528500
  13. Calverley et al. "A systematic review of alcohol education programs for young people: do these programs change behavior?" Health education research (2020) doi:10.1093/her/cyaa049. https://academic.oup.com/her/article-abstract/36/1/87/6031209?redirectedFrom=fulltext
  14. ​Campbell et al. "Wearable electrochemical alcohol biosensors" Current opinion in electrochemistry (2018) doi:10.1016/j.coelec.2018.05.014.