Maine License Plate Reader Laws

Status at a glance

Who may use an ALPR in Maine

Section 2117-A starts from a prohibition: “Except as otherwise provided in subsection 3, a person may not use an automated license plate recognition system” (subsection 2). Subsection 3 lists the exceptions:

• the Department of Transportation, to protect public safety and transportation infrastructure;
• the State Police, for commercial motor vehicle screening and inspection; and
• any state, county or municipal law enforcement agency “when providing public safety, conducting criminal investigations and ensuring compliance with local, state and federal laws.”

Authorized users may use a system “only for the official and legitimate purposes of the user’s employer.” Toll-enforcement photo monitoring is excluded from the definition. On its face, the prohibition isn’t limited to government users. How it applies to privately owned systems, such as cameras run by businesses or homeowners’ associations, is something we haven’t verified. See private and HOA cameras.

What can go on a hotlist

For law enforcement use, a system “may use only” three kinds of information: information entered by a law enforcement officer “based on specific and articulable facts of a concern for safety, wrongdoing or a criminal investigation or pursuant to a civil order”; records from the NCIC database; or an official published law enforcement bulletin (subsection 3(C)). For how hotlist entries become alerts, see ALPR hotlists and alerts.

Retention: 21 days

Data that isn’t “intelligence and investigative record information” as defined in 16 M.R.S. § 803(7), or commercial vehicle screening data, “may not be stored for more than 21 days” (subsection 5). The State Police policy applies the same 21-day limit to its scan data.

Confidentiality

ALPR data “are confidential under Title 1, chapter 13,” Maine’s public records law. It is available only to a law enforcement agency carrying out its functions, or to an authorized agency for its intended purpose, “and any related civil or criminal proceeding” (subsection 4). Agencies may release aggregate summary reports that don’t reveal an individual’s activities. A violation of the section is a Class E crime (subsection 6).

Maine State Police policy

General Order E-140, marked as publicly disclosable, adds operational rules for State Police systems:

• It acknowledges that systems “at times may produce erroneous alerts,” for example due to damaged plates or a misidentified state.
• Before taking action based solely on an alert, an officer shall, “whenever reasonably practicable,” visually verify that the plate characters and the issuing state match. The officer must also determine whether the alert concerns the vehicle’s registrant or the vehicle itself.
• Hotlists must be updated “as often as reasonably practicable.”
• A system found not to be working properly must not be used.
• A memorandum of understanding is required before ALPR data is shared electronically and directly with another law enforcement agency.

This policy governs the State Police. Municipal departments may have their own policies.

What this can mean in a Maine case

• Was the system operated by an authorized user under subsection 3?
• Where did the hotlist entry come from: officer-entered on specific and articulable facts, NCIC, or a published bulletin?
• Was data kept beyond 21 days, and if so, was it intelligence and investigative record information?
• For a stop on an alert, were the plate characters, the state, and whether the alert concerned the registrant or the vehicle checked first? See ALPR alert traffic stops.

The confidentiality provision expressly allows use of ALPR data in “any related civil or criminal proceeding.” How defense access works in practice is a question for local counsel. See requesting ALPR records in discovery.