The Use of Automatic License Plate Readers by Police is Not Illegal

• Steven Topazio wrote this January 8, 2024 at 5:02 pm

In a recent SJC slip decision, the court affirmed the denial of the defendant’s motions to suppress, concluding that while the defendant has a constitutionally protected expectation of privacy in the whole of his public movements, an interest which potentially could be implicated by the widespread use of [automatic license plate readers (ALPRs)], that interest is not invaded by the limited extent and use of ALPR data in this case. Commonwealth v. McCarthy (No. SJC-12750) – April 16, 2020

Automatic license plate readers are cameras combined with software that allows them to identify and “read” license plates on passing vehicles. When an ALPR identifies a license plate, it records a photograph of the plate, the system’s interpretation of the license plate number, and other data, such as the date, time, location, direction of travel, and travel lane. In Massachusetts, cameras owned and maintained by the State police feed this information into a database maintained by the Executive Office of Public Safety and Security (EOPSS).

At some point in 2015, the State police installed fixed camera readers on both sides of the Sagamore and Bourne bridges. While these cameras are not infallible, they essentially create a comprehensive record of vehicles traveling onto or off of the Cape.

While investigating the defendant on suspicion of drug distribution, police used automatic license plate readers (ALPRs) on the Bourne and Sagamore bridges to track his movements. They accessed historical data, which revealed the number of times he had crossed the bridges over a three-month period, and also received real-time alerts, one of which led to his arrest. The court had to determine whether the use of ALPR technology in this case constituted a search under the Fourth Amendment to the United States Constitution or under art. 14 of the Massachusetts Declaration of Rights. The court concluded that while the defendant has a constitutionally protected expectation of privacy in the whole of his public movements, an interest which potentially could be implicated by the widespread use of ALPRs, that interest is not invaded by the limited extent and use of ALPR data in this case.

Background photo courtesy of: Alice Donovan Rouse