Montana

Montana ALPR law

§ 46-5-117 to -119

Prohibits the use of ALPRs by an agency or employee of the state or any subdivision of the state on any public highway. Provides exceptions for specific agencies or purposes, including state or local law enforcement and the department of transportation, if specified requirements are met. Authorized use for planning, parking, ports of entry operations, and specified law enforcement uses including identifying vehicles that are stolen, associated with wanted, missing or endangered persons, registered to a person with a warrant, in violation of commercial trucking requirements, involved in case-specific surveillance, involved in a homicide or other major incident or in the vicinity and may be connected to a crime. State or local law enforcement agencies that use an ALPR system shall adopt and publish a written policy governing use before a system becomes operational. The policy must address database comparison, retention of data, sharing of data, training, supervisory oversight, access to and security of data, access to data obtained by ALPR systems operated by the law enforcement agency and any other subjects related to law enforcement use. Law enforcement agencies must maintain records of users indefinitely and keep system maintenance and calibration on file. At least once every year, law enforcement agencies must audit the ALPR system’s use and effectiveness. Except as provided, license plate data captured by law enforcement may not be preserved for more than 90 days after the date that the data is captured. One year from the date of the initial preservation request, if one was made, the captured license plate data must be destroyed unless the custodian receives another preservation request. The one-year retention period is resets based on the date of the second request. Data may be maintained only for the minimum time necessary but no more than 18 months. Data is confidential and exempted from public records.

Summary quoted from NCSL, Automated License Plate Readers: State Statutes, updated September 28, 2026. Not legal advice; read the statute.