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Fourth Amendment

State Constitutional Privacy Protections and ALPR

Published · Last reviewed · By Editorial team · Not attorney-reviewed

Short answer

A state constitution can protect privacy more than the Fourth Amendment. Supreme courts in Hawaii, New Mexico, New Jersey and Oregon, among others, have said theirs do. None of the decisions we verified applies that to license plate readers, but a state claim can still matter: state courts decide what counts as a search under their own constitution.

Why state constitutions matter

The Fourth Amendment sets a minimum. State constitutions have their own search-and-seizure provisions, and each state’s highest court decides what its provision means. It can read the state provision to protect more than the federal one, and it can reach that result on the state constitution alone. Then federal decisions don’t control the outcome.

This matters for license plate readers because the federal question is unsettled (see is ALPR a search?). In Commonwealth v. McCarthy (2020), Massachusetts’s highest court analyzed ALPR use under both the Fourth Amendment and Article 14 of the Massachusetts Declaration of Rights. It warned: “With enough cameras in enough locations, the historic location data from an ALPR system in Massachusetts would invade a reasonable expectation of privacy and would constitute a search for constitutional purposes.”

States where courts have said so

These decisions say the state constitution protects more than the Fourth Amendment. None is an ALPR case. Each state page has the details and sources.

StateDecisionWhat the court said
HawaiiState v. Rodrigues (2012)Article I, section 7 “provides broader protection than the [F]ourth [A]mendment to the United States Constitution because it also protects against unreasonable invasions of privacy.”
New MexicoState v. Crane, 2014-NMSC-026“New Mexico courts have long held that Article II, Section 10 provides greater protection of individual privacy than the Fourth Amendment.” Applied to sealed garbage placed out for collection.
New JerseyState v. Manning (2020)Recalled that State v. Earls (2013) recognized “an expectation of privacy in cell-phone location information cognizable under the New Jersey Constitution,” and held the exclusionary rule applies to unconstitutional searches of cell-phone records under Article I, Paragraph 7.
OregonState v. De Witt Simons (2026)“What constitutes a search under Article I, section 9, differs from what constitutes a search under the Fourth Amendment to the United States Constitution.” Restated State v. Campbell (1988) on secretly attaching a radio transmitter to a car to monitor its movements.
ColoradoPeople v. McKnight (2019)Described Colorado’s history of broader readings, including a tracking-device case, but added: “in recent years, we have moved away from this interpretive independence.”

Broader readings that are narrow

In some states, a broader reading exists but is limited to a context far from location surveillance:

  • Arizona: broader only for warrantless home entries (State v. Mixton, 2021).
  • Ohio: broader only for warrantless arrests for minor misdemeanors (State v. Brown, 2003).
  • Iowa: departed from federal law on curbside trash searches (State v. Wright, 2021). How far it reaches is a judgment call.
  • Pennsylvania: Article I, Section 8 has been held to give greater protection in some contexts, as described in a 2026 concurrence. Separately, a 2023 Superior Court decision held LPR use wasn’t a Fourth Amendment search.

A broader reading in one context doesn’t mean a court will apply it to ALPR data.

How this can come up in an ALPR case

  • A separate claim. A defense can argue that ALPR use was a search under the state constitution even if it wasn’t under the Fourth Amendment. Location cases are the closest analogies: cell-phone location in New Jersey (Earls), vehicle tracking in Oregon (Campbell), and ALPR networks themselves in Massachusetts (McCarthy). See the mosaic theory.
  • Raising it properly. States have their own rules for how a state constitutional claim must be raised. In New Mexico, for example, Crane applied the “interstitial approach” of State v. Gomez, which also governs how such a claim must be raised and preserved.
  • The remedy. State exclusionary rules can differ from the federal one. In Manning, the New Jersey Supreme Court applied the exclusionary rule under Article I, Paragraph 7, and the records had to be suppressed. Compare the federal exceptions in exceptions to the exclusionary rule.
  • Statutes too. Some states also regulate ALPRs by statute, and a few make evidence inadmissible when the statute is violated. See the state law comparison.

What’s unsettled

  • We haven’t found a state supreme court decision holding that ALPR use is a search under a state constitution. McCarthy held that four bridge cameras weren’t.
  • States that read their constitutions more broadly in one context may not do so for ALPR data. Colorado’s court has said it has moved away from interpretive independence.
  • We cover a state’s constitutional reading only after verifying it from the opinion. Other states may have relevant decisions we haven’t reviewed.

Law varies by state. State constitutions, statutes and courts may treat this issue differently from federal law. A licensed attorney in your jurisdiction can tell you how it applies.

Sources

  1. OpinionCommonwealth v. McCarthy (slip opinion, SJC-12750)484 Mass. 493 (2020)
  2. OpinionState v. Rodrigues, Supreme Court of HawaiiNo. SCWC-30692 (Haw. Oct. 12, 2012)
  3. OpinionState v. Crane, Supreme Court of New Mexico2014-NMSC-026 (filed June 30, 2014)
  4. OpinionState v. Manning, Supreme Court of New JerseyA-10-18 (N.J. Jan. 13, 2020)
  5. OpinionState v. De Witt Simons, Oregon Supreme Court375 Or 70 (2026), decided March 26, 2026
  6. OpinionPeople v. McKnight, Supreme Court of Colorado2019 CO 36 (Colo. May 20, 2019)