St. Mary's Law Journal


The reliability of LIDAR (Light Detection and Ranging) is generally questioned for one of two reasons. First, when the speeding charge is of such great importance to the defendant that he must challenge the technology. Second, when the defendant is charged with a different and more serious crime because of the traffic stop. In this instance the reliability of the equipment provides the opportunity to question the stops’ underlying probable cause. Assuming the particular jurisdiction has not settled the issue of reliability of LIDAR evidence, the court must require the prosecutor to present expert testimony to show reliability. In the 2009 decision in Hall v. State, the Texas Court of Criminal Appeal failed to hold LIDAR evidence reliable. This decision prevents all lower courts from taking judicial notice. A ruling on the liability of LIDAR by Texas’s highest criminal court would undoubtedly have national implications. Ultimately, the Hall case does very little for LIDAR jurisdiction. In order for the highest Texas criminal court to address the issue, the prosecution would have to put on evidence at the trial level. While there appears to be no doubt that laser speed measurement systems are based on solid science, judicial notice of these facts would eliminate costs and delays. Yet, after the Hall case, it seems likely this will only happen through the legislative process. While waiting, prosecutors can do several things in order to save resources. First, ensure all officers using the technology are properly trained. Second, make sure all maintenance records are being properly preserved by law enforcement. Finally, when attempting to avoid the expense of expert witnesses, prosecutors can ask the trial court itself to take judicial notice. Otherwise, prosecutors must build the record for appeal so Texas high courts can properly address the actual reliability of LIDAR.


St. Mary's University School of Law