The SCRAM Tether, How it Works and How it Doesn’t

In courts all over Michigan, judges routinely order anyone who has been convicted of an alcohol related offense to refrain from the use of alcohol. It is increasingly common for a person just accused of drunk driving, before any conviction, to be ordered not to drink alcohol.  To enforce these orders the court utilizes several means of alcohol consumption detection. The most common is a randomly administered breath test, typically on a device called a PBT – preliminary breath test. The PBT is administered by a person either at a police department, a probation officer or an employee from a company that performs this service like JAMS. A second alcohol testing option that is increasingly becoming more common is the use of a SCRAM. The SCRAM ankle bracelet is a device used by judges and probation officers to determine if an individual has been drinking alcohol. The SCRAM is permanently affixed to a person’s lower leg, above their ankle, like a traditional tether. It is designed to detect alcohol consumption on a continuous basis, 24 hours a day.

SCRAM is an acronym that stands for Secure Continuous Remote Alcohol Monitor. The device looks like a tether, secured against the skin and regularly takes a sample of a person’s sweat usually every thirty minutes. More accurately, the SCRAM measures the gas alcohol concentration over the skin. The device then analyzes it for alcohol. If the device detects alcohol it will take readings more often. The SCRAM will take the alcohol readings and, using a formula and programming created by its manufacturer, reports the alcohol content in terms of a TAC – transdermal alcohol content. The TAC is supposed equate to BAC – blood alcohol content as its expressed for DUI prosecutions. The data is stored in the device until it is downloaded via an at home located modem or at the agency provider who administers the unit. The data is collected and reported in a graph to be analyzed by an employee trained to properly do so to determine if the graph represents an alcohol consumption event and violation to be referred to the judge or probation officer.

The SCRAM tether was invented and is owned by Alcohol Monitoring Systems, Inc. (AMS) located in Highlands Ranch, Colorado. Jeff Hawthorne co-invented the device in 1993 and founded AMS in 1997. SCRAM was introduced to the criminal justice market by AMS in 2003 and is currently used in 48 states and monitors over 184,000 clients.  Hawthorne serves as its Chief Technology Officer and travels the country to provide court testimony supporting the reliability of the device and its data interpretation. He has a BA in electrical engineering from Colorado State and an MBA from Regis University in Denver. AMS employees are trained, certified and are solely responsible for analyzing and interpreting the data collected by the SCRAM device.

AMS leases the SCRAM device and the administrative services required to utilize it to local authorized service providers. House Arrest Services, located in Eastpointe, Michigan is the largest provider in the Metro Detroit Area. The employees at House Arrest receive training from AMS on the intake, installation, proper fit, removal, ongoing maintenance and initialization of the device. House Arrest Services is not responsible or trained to interpret the data generated by the SCRAM.

Since its inception, SCRAM has had two major upgrades. In 2008 the SCRAM II was introduced which used the same technology but was smaller, lighter and the two components fit into one case instead of two cases. In 2010 AMS introduced the SCRAMx which combined the alcohol monitoring with house arrest services.

The SCRAM has several anti-tampering devices. A one time, disposable tamper clip is used to secure the bracelet straps and battery. The clip must be physically damaged if the SCRAM is removed therefore leaving a clear indicator if the device or strap has been tampered with .Next the SCRAM continuously monitors the skin’s temperature which is typically constant. There is also an infrared device which sends a beam of light which is bounced off the skin and returned to a detector which reads the distance voltage which remains constant unless tampered with. If any of these readings reach the parameters set by AMS an alert is generated which may be reported to the service provider.

The SCRAM utilizes fuel cell technology to detect alcohol in the perspiration pumped from the device. It is the same technology used with most PBTs. It’s designed to convert the alcohol into an electrical current the strength of which is converted into an alcohol concentration. The major drawback in this technology is that it is not specific to ethyl alcohol, the type of alcohol that is consumed by people. There are other types of alcohol that the fuel cell will read and report as a possible drinking event. Isopropyl alcohol is an alcohol commonly found in cleaning products. Methanol alcohol is the primary ingredient in the fuel burned by engines. Cetyl alcohol is found in many body washes and Jergens hand and body lotion. All of these alcohols, and others, will be detected by the SCRAM. The data that is generated by the fuel cell is interpreted exclusively by AMS employees. They are the only people who are trained to determine if the alcohol readings are, in fact the result of a drinking event or if the readings were caused by an interferant. They make their determinations and conclusions primarily based upon the analysis of the graph that the data creates. They also consider and compare average rates at which people’s BAC rises and falls when drinking.

When consumed by the body, Ethyl alcohol has a somewhat predictable curve that is generated in relation to the concentration of alcohol in the blood stream. The curve begins with zero, rises to a peak then falls back to zero. Due to the physiology of alcohol in the human body, the time it takes to rise and fall, depending on how much a person has drank and their sex can be predictable. Because of that predictability AMS technicians attempt to identify and distinguish a drinking event from an interferant. There are several problems with this analysis. As it is true that interferant’s often do not mimic a BAC ethyl alcohol curve, they also often do. The curve will depend upon the type of interferant, its access to the skin and the amount absorbed by the skin.

It is well settled that the skin will absorb environmental alcohol when it is present. Therefore, depending how much environmental alcohol is present, and the type is directly correlated with how much will be absorbed. If a sufficient amount is absorbed, the rate at which it dissipates can easily be mis-interpreted as a drinking event thereby unfairly subjecting the wearer to possible incarceration. There are several common products containing environmental alcohols which could be mistaken for ethyl alcohol including: body washes, perfumes, colognes, gasoline, Jergens Body Lotion, mouthwash, household cleaners or other hygienic products that contain alcohol. There are many products people use every day that they are not aware contain alcohol.


If there is an allegation that a person violated a court order by drinking alcohol that has been confirmed by the SCRAM tether it is important not to admit any guilt and request a hearing which is that person’s legal right. An attorney representing this person must have a very good understanding of the science supporting transdermal alcohol testing and be very familiar with the SCRAM unit and how it operates. Prior to the hearing it is important to request, receive and review all relevant supporting SCRAM documentation, including TAC graphs  which must be provided by either the service provider, the prosecuting attorney, or the probation officer. It is important to receive all relevant documents including ones that provide the alert notifications generated by the device. Several different notifications can be generated including an alcohol interferant detected message, temperature warning messages, IR distance warning message, and the bracelet damage message. It is common for the prosecution or probation officer to refrain from providing the alerts which can expose problems with the operation of the SCRAM. A good attorney must demand these additional reports that almost always exist. When all of the available information and data has been collected it must be analyzed along with a detailed account from the accused regarding their activities during the relevant time periods. It is also imperative to review all common alcohol interferants with the accused to discover the source of the alcohol readings. It is important for the attorney to have a detailed medical history from the accused which can also reveal reasons for false positive SCRAM results. It is important to provide the court with a reasonable explanation, if possible, for the positive readings. Without an explanation, the court sometimes will automatically believe the AMS’s determination of a drinking event.

It is also important for the attorney to understand that only the AMS employee has been trained to analyze the data generated by the SCRAM. Often times the prosecuting attorney or probation officer will seek to have the service provider employee to provide the testimony necessary to introduce the SCRAM TAC graphs and alcohol drinking confirmatory opinions of AMS. Service provider employees have not been trained and certified to provide an explanation as to why the evidence suggests a drinking event. They will only state that an AMS employee made that opinion which, of course, the service provider always supports. It may be advisable to obtain an alcohol hair test ($250) which can go back up to three months and/or a polygraph examination ($500). Costs are approximated. A defense expert is often times very persuasive to the Court when determining guilt or innocence.

Several courts have found the SCRAM not reliable enough to have the potential to deprive someone’s liberty and therefore should not be utilized. Most notably, Judge Dennis Powers of the 52-1 Judicial District Court in the City of Novi has written and published an article about the ineffectiveness of the SCRAM called The SCRAM tether as Seen Through the Eyes of Davis-Frye and Daubert. Judge Powers conducted a hearing in which Jeff Hawthorn, and other experts, provided testimony. Judge Powers ruled that the SCRAM did not meet the requisite standards of reliability in the relevant scientific community necessary for court admissibility.

All courts are not bound by Judge Powers’ ruling. Many courts have accepted the SCRAM as a useful tool in detecting alcohol consumption. To effectively fight false allegations requires an experienced and knowledgeable attorney who can educate the Court and expose the flaws that are inherent in transdermal alcohol testing and the SCRAM tether.

If you need an experienced attorney for Oakland, Wayne or Macomb County communities of Royal Oak, Troy, Rochester Hills, Detroit, Sterling Heights, Warren, Clinton Township or the surrounding area who knows the science behind bodily alcohol content testing call The Law Office of Barton Morris at (248) 541-2600 or send an email to



November 26th, 2012|