Sometimes, investigators have to dig deep and learn an entirely new technology, to better serve their clients.
Private investigators these days find themselves delving into all sorts of differing arenas. We’re expected to become “pseudo experts” in everything from cellular logs and triangulation to the germination period of Bermuda grass — which often entails researching and testifying on subjects that to date have been foreign to us.
Recently, our office has experienced a strange phenomenon — an unexpected rush of a certain type of case. As always, it started with one call: “Bohn & Associates, how may I help you?”
The case, in its essence went like this: The client, “Jack,” was a DUI multiple offender on a very strict probation. The State was seeking to revoke his probation due to “a positive alcohol event.”
Seems cut and dried, right? Well, it wasn’t. Thus, our foray into the realm of Transdermal Alcohol Monitoring began.
What is Transdermal Alcohol Monitoring?
The science behind this technology has been around for decades. The basic idea is that the skin is porous, thereby allowing the transfer of chemical information through the epidermal layer. This idea has been proven and implemented by the use of pain patches, nicotine patches and the like. The scientists behind the introduction of transdermal alcohol technology took this concept and reverse engineered it.
The theory goes like this: As the body metabolizes alcohol, there is a discharge of alcohol that passes through the skin by means of perspiration, forming a measurable layer on the skin surface. Researchers found a way to measure this escaping alcohol and created a product which (similar to ankle monitors worn by people under house arrest) takes regular measurements of the transdermal alcohol concentration, or TAC.
Anatomy of the Transdermal Alcohol Monitor
Enter onto the scene the “BLAST unit” by “ABC” Incorporated (fictitious names). As previously described, it looks similar to an ankle monitor used for house arrest. Depending on the model, it has two or three functions. Function one is exactly what one would expect — the alcohol monitoring aspect. Function two is an “anti-tamper” configuration, and the third and optional function is GPS.
Function one: The continuous alcohol monitor takes transdermal readings every thirty minutes, automatically comparing the readings with previous readings. The unit transmits these results to the “ABC” headquarters, where they are analyzed by the “ABC” computers. If alcohol is detected by the unit, the report is “flagged” and analyzed by “ABC” personnel. Once the flag has been “confirmed,” a report is generated and sent to the end-user, usually a probation or parole officer.
Function two: The monitor has a redundant system to monitor for potential tampering. Tampering with this type of device is generally considered as any attempt to prevent the unit from performing its first and most essential function, alcohol monitoring. A tampering event could be caused by the wearer placing something between the device and the skin. Examples reported range from everything from a playing card to a slice of bologna.
The first anti- tampering system is a constant measurement of the temperature of the skin. The second is an infrared (IR) reading. This IR reading is generated by a consistent pulse of IR that contacts the skin and bounces back to the unit. This reading measures the distance of the unit from the surface of the skin. If the unit senses a variance with temperature or IR reading it again “flags” a potential tamper. As with the potential alcohol, a potential tamper is then analyzed by “ABC” staff.
Criteria and “Recommended” Procedures
“ABC” does not issue policies and procedures to the end-users (probation or parole), but rather “suggested procedures.” One could gather that this move is to avoid legal liability resulting from false positives, mis-readings, device failures, or malicious persecution cases. Whatever the reason, we have found that courts are prone to accept these guidelines. That has proved helpful in the defense of these cases.
When a “potential alcohol” flag is received by “ABC,” it is reviewed and analyzed in house then reported to the end-user. They then recommend that the end-user investigate further. The recommendation is that the wearer is immediately brought in for interviews and further testing. In our experience, this step is at times skipped. Which, as part of a larger case, contributes to reasonable doubt. A “potential alcohol event” is considered “confirmed” when there are three sequential readings of 0.020 transdermal alcohol concentration (TAC) or above.
Upon receiving a “potential tamper flag,” “ABC” again will internally review the report and determine if the “potential” is anomalous or should be elevated to “confirmed” status. Once “confirmed,” the report is distributed to the end-user.
There are two criteria used to “confirm” a tamper: “with alcohol” and “without alcohol.” The “ABC” guidelines state that in order for a tamper to be elevated to “confirmed” the following guidelines dictate:
With a deviation in the IR voltage of either + 12% or -17% from the baseline or more for a period of eight hours with no transdermal alcohol concentration (TAC) or a deviation in the IR voltage of either + 12% or -17% from the baseline or more for a period of three hours with a TAC reading, the “tamper” report will be generated and sent to “ABC” staff for evaluation.
Once generated from “ABC,” this data is reported in a graph demonstrating the TAC, voltage and temperature readings. This report is then transmitted to the end-user where revocation decisions are made. If the decision to revoke is made, then the lawyers (and investigators) get involved.
Shortcomings, Failures and Holes
In order to explain the exploitable shortcomings we’ve uncovered through our research, we’ll share two case studies. Both will demonstrate failures on the part of the end-user and failures involving “ABC” and their reporting criteria.
Case Study One: “Jack”
Jack has the distinction of having multiple DUI convictions and being on a very strict probation, to include the installation of the “BLAST” unit. At the time of our involvement, Jack had been wearing the unit for five years. Yes, that’s right: five years, without incident. It is important to note, “ABC Corporation” recommends that the unit be employed for a period of 90 – 180 days. Jack has had his for FIVE YEARS!
Unbeknownst to Jack or his attorneys, the probation department received a report from “ABC” showing a “potential” alcohol and tamper event. The report was from three months prior, and probation did nothing with it. Jack’s case came up for a normal judicial review process. During this administrative hearing, the prosecutor questioned Jack’s probation officer, who testified that the defendant was in full compliance with all probation requirements, and that there had been no incidences to report.
The hearing was adjourned and the Judge left the courtroom. Then, without warning, the prosecutor ordered nearby bailiffs to take Jack into custody and charged him with probation violation. Jack, his family, his legal team, and even the probation officer were stunned. The precursor of the prosecutor’s pursuance of revocation, you may ask? The report from “ABC.”
That’s when our firm was hired.
[Cue dramatic music and furious study montage.]
At the time, nobody at our firm even knew these devices existed. Our investigators quickly read everything we could find on the subject. Soon, we found ourselves able to read, interpret and analyze the graphs and reports from “ABC.” They were revealing.
You, the reader, may remember the criteria from “ABC’s” own documentation defining an alcohol event: Three consecutive readings of at least 0.020 TAC. This requirement is due to what “ABC” refers to as possible “interferents.” Interferents are defined as “contaminants that may cause an elevated alcohol concentration reading.” They include sunscreen, bug spray, perfumes, colognes, cleaning agents, antibacterial hand soaps — anything that contains any amount of alcohol in its composition.
Now remember the standard: three consecutive readings of 0.020.
Our client had a single reading of 0.006 — not even close to the criterion of 0.020. That was the first gaping hole in the prosecutor’s case.
The second was the handling of the report. You may remember the “suggested procedure” of contacting the wearer as soon as possible after the generation of a report for further investigation and testing. That never happened in this case.
In other words, our client was robbed of any opportunity to prove his innocence. Upon our investigation into the day in question, we discovered that the client had spent the day fishing with his teenaged son, and — you guessed it — he had used both sunscreen and bug spray.
The next hurdle was the “potential tamper.” There was a period of time prior to the “potential alcohol event” that the temperature and IR reading differed from the base line readings. This period of “tamper” still did not fall within the suggest guidelines. However, it was necessary to look into and provide an explanation.
Have you, the reader, ever launched and loaded a boat? Well, our client did that day. You may be able to imagine the possible effect that a sudden plunge of the foot into cold water could have on temperature and IR readings. This contributed to our operating theory regarding the “tamper” alert.
One of our investigators testified in the revocation hearing. Once the results of our investigation were presented, the prosecution pulled their revocation order.
Case Study Two: “Jill”
Several months after the first case, the office phone rang again. It was an attorney from another city, hours away. She’d heard about our success with Jack’s case and was in a similar situation with her client. After an initial consult, she sent over the reports. Jill’s report showed no alcohol event of any kind and a “confirmed tamper.”
We analyzed the “tamper” and quickly discovered that “ABC” had forwarded the report after failing to follow their own guidelines! Without getting into the weeds, you may remember that there were certain voltage differentials that determined a tamper. The voltage differentials, though outside of the normal, failed to meet the minimum “ABC” criteria.
Additionally, Jill had recently experienced some weight loss, which caused the monitor to become looser. Our investigators wrote up our findings in a report for the attorney, who then shared it with the prosecution, who then promptly dropped the case.
Conclusion
Jack’s case highlighted the problems associated with a failure on the part of the end-user. Jill’s case showcased a failure on the part of “ABC.”
As with any criminal case, the investigator searches for and exploits any holes in the case presented. But let’s be honest: In order to find and exploit holes, one must first know where to look.
Transdermal Alcohol Monitoring technology has the potential to be a great deterrent and opportunity for rehabilitation. However, it also has the potential to be misused and even abused.
As with any other case, these transdermal monitoring cases can be fought and won. It takes diligence, study, perseverance, and an eye for the details. It’s amazing what an investigator can do if willing to become educated and dig a little.
If the reader encounters such a case, our investigators would be happy to consult and share our knowledge and experience.
Post Script
There’s another case worth discussing: “Darrell.” We received Darrell’s report and immediately contacted his counsel. “Take whatever deal that you can negotiate,” we said. See, Darrell’s report was a textbook picture of a “confirmed alcohol event,” and there was no arguing it. Sometimes, that happens, too.
About the authors:
Mindy R. Bohn is the founder and lead investigator at Bohn & Associates. She brings a wealth of business experience and an inquisitive mind to every case. In addition to her Certification through Professional Development Institute, University of North Texas, she has earned Occupational Safety & Health Administration certification in “Basic Accident Investigation” and “Effective Accident Investigation.”
Clay A. Kahler, B.A., M.Rs, M.A., Ph.D. brings an extensive background of military police and civilian law enforcement experience. He has earned degrees in Biblical Studies and Theology. He is an author, instructor, professor, lecturer and pastor. Clay also holds OSHA certifications in “Basic Accident Investigation” and “Effective Accident Investigation” as well as numerous certifications from the Federal Emergency Management Administration.


