Ignition Interlock Supervision

If you are charged with a DWI, you may be ordered by the judge or magistrate to install an ignition interlock device on your vehicle and to report to the Pretrial Services Office for verification of installation and monitoring of the interlock device.

About Ignition Interlock Devices

An ignition interlock device is a breath alcohol analyzer that is installed onto a motor vehicle ignition. In order to start the vehicle, a driver must blow a breath sample into the analyzer which measures alcohol concentration. If the alcohol concentration exceeds the startup set point on the interlock device, the motor vehicle will not start (Title 37 Texas Administrative Code Rule 19.21).


If you have been released from jail with orders for ignition interlock device installation, please report to the Pretrial Services Office on the assigned date with proof of installation and the $10 monthly supervision fee. The device must be installed with proof of installation, insurance and registration of the vehicle by the given deadline date (within 30 days from the date of release from custody).

Any and all violations will be reported by the DWI Ignition Interlock Officer directly to the court of jurisdiction.