Commonwealth v. McCarthy, 142 N.E.3d 1090

Background

Automatic license plate readers (ALPRs) on the Bourne and Sagamore bridges record plate images, plate numbers, date/time, location, direction, and retain data (EOPSS policy: one‑year retention).
Barnstable police placed the defendant's Hyundai plate on an ALPR "hot list" after drug investigation; real‑time alerts notified officers when the vehicle crossed the bridges.
Alerts led officers to observe two brief roadside meetings between the defendant and a codefendant; police generated a historical ALPR spreadsheet covering Dec 1, 2016–Feb 12, 2017 showing frequent Cape crossings.
On Feb 22, 2017 police stopped, handcuffed, and arrested the defendant; at the station he waived Miranda and made incriminating statements; phones and cash were seized.
Defendant moved to suppress ALPR data and fruits of the arrest; the Superior Court denied suppression and the interlocutory appeal was allowed to the SJC.

Issues

Issue	Plaintiff's Argument	Defendant's Argument	Held
Did ALPR use constitute a constitutional "search" (Fourth Amendment and art. 14)?	ALPR alerts + year‑long historical data produce aggregated location tracking (mosaic) and thus a search.	Limited ALPR deployment (4 cameras at 2 bridge endpoints) only shows crossings onto/off Cape; no full‑movement mosaic.	No search here: four cameras at bridge endpoints did not reveal the "whole of" defendant's movements; ALPR use in this case not a search.
Do deficiencies or absence of a written ALPR policy require suppression?	Without a clear written policy, use is prone to arbitrary or unlawful searches; evidence should be excluded.	Policy gaps do not determine the threshold constitutional question whether a search occurred.	Policy absence/deficiencies do not control the constitutional analysis; suppression not required on that basis.
Do federal statutes (SCA, ECPA) constrain police ALPR use?	ALPR access/alerts implicate Stored Communications Act or ECPA protections.	Government created and used the ALPR data; statutes regulating third‑party communications interception/production do not apply.	SCA and ECPA inapplicable to this type of ALPR data collection/use.
May defendant assert "target standing" to challenge searches of third parties?	Defendant seeks to challenge codefendant searches as a secondary target.	Target standing is not recognized absent ‘‘distinctly egregious’’ police conduct.	Court declined to adopt target standing here; none of the facts showed egregious conduct.
Were Miranda waiver and subsequent statements voluntary despite officer deception?	Officers' statements that defendant was not under arrest induced an involuntary waiver/statement.	Deception alone does not automatically render a Miranda waiver involuntary; the totality of circumstances controls.	Waiver and statements deemed voluntary under totality of circumstances; admissible.

Key Cases Cited

Katz v. United States, 389 U.S. 347 (establishes reasonable expectation of privacy test)
Carpenter v. United States, 138 S. Ct. 2206 (aggregation of location data can implicate privacy; historical CSLI requires heightened scrutiny)
United States v. Jones, 565 U.S. 400 (GPS tracking and concerns about prolonged surveillance)
United States v. Knotts, 460 U.S. 276 (single‑journey beeper tracking does not implicate a reasonable expectation of privacy)
Kyllo v. United States, 533 U.S. 27 (technology‑aided surveillance can implicate Fourth Amendment protections)
Riley v. California, 573 U.S. 373 (digital searches raise special concerns; need for careful rules)
Commonwealth v. Augustine, 467 Mass. 230 (CSLI and sustained electronic monitoring implicated art. 14)
Commonwealth v. Rousseau, 465 Mass. 372 (GPS monitoring of public movements constitutes search under art. 14)
Commonwealth v. Estabrook, 472 Mass. 852 (length of location data requested is the salient consideration)
Commonwealth v. Almonor, 482 Mass. 35 (recent Massachusetts guidance on technology, privacy, and searches)