An alcohol ignition interlock device (IID) is a breath-test device that is connected to a vehicle’s ignition. A vehicle with an IID installed will not start unless the driver blows into the interlock and has a blood alcohol concentration (BAC) below a limit set by the court—usually .02 BAC. IIDs must be installed by a certified technician approved by the state’s department of motor vehicles (DMV). The IID will collect data (engine starts and stops, breath test results, and tampering attempts) and report it to the monitoring company, which will report it to the court.

IIDs reduce repeat offenses for DUI/DWI by approximately 70% when installed. Laws vary from state to state and courts have significant discretion, but a judge may order a person convicted of a first DUI/DWI offense to install an IID and will order a person convicted of a second or third DUI/DWI to install an IID. Courts will often order an IID installed on the defendant’s vehicle as a condition of bond (to be released from jail) and of probation (following jail or prison time, or in lieu of any or more jail or prison time). The court may order the defendant’s IID to remain on the vehicle for 1-3 years or more.

Despite these laws and programs, only about one-fifth of those arrested for DUI/DWI have an IID installed.

In New Mexico (NM), the use of an alcohol ignition interlock device (IID) is a common legal requirement for individuals convicted of driving under the influence (DUI) or driving while intoxicated (DWI). New Mexico law mandates the installation of an IID for all offenders convicted of DUI/DWI, including first-time offenders. The state's Motor Vehicle Division (MVD) oversees the certification of technicians who install IIDs, and the devices must be able to record data such as engine starts and stops, breath test results, and any tampering attempts. This data is reported to the monitoring company and subsequently to the court. The duration for which an IID must be installed varies, but it can range from one year to several years, depending on the severity of the offense and the discretion of the court. The BAC limit for IIDs in New Mexico is typically set at .02. The requirement for an IID may be imposed as a condition of bond or probation, and its use has been shown to significantly reduce the rate of repeat DUI/DWI offenses. Despite the effectiveness of IIDs and the legal requirements, compliance rates for installation are not as high as the law intends.