A report is available on the results of a randomized field experiment with license plate readers (LPR) conducted by the Police Executive Research Forum and the Mesa (Ariz.) Police Department to target the problem of auto theft. The experiment sought to determine whether and to what extent LPR use improves the ability of police to recover stolen cars, apprehend auto thieves and deter auto theft. The National Institute of Justice-funded project examined the operations of a specialized four-car police auto theft unit that worked in auto theft hot spots over a period of time both with and without LPR devices. The study showed that LPR use considerably enhanced the productivity of the auto theft unit in checking license plates, detecting stolen vehicles and plates, apprehending auto thieves and recovering stolen vehicles. The use of LPRs resulted in eight to 10 times more plates checked, nearly three times as many "hits" for stolen vehicles and twice as many vehicle recoveries. Click on the title to read Combating Auto Theft inArizona: A Randomized Experiment with License Plate Recognition Technology. (This report is the result of a National Institute of Justice-funded project but was not published by the U.S. Department of Justice.)