Police Used Flock Cameras to Track Driver Across State Lines for Cannabis Search

Interstate Surveillance Network Built Traffic-Stop Pretext

Police tracked the driver's vehicle through multiple jurisdictions using networked Flock cameras before initiating the stop. The automated license-plate recognition system let officers monitor the subject's movements without physical surveillance, according to the court record reviewed by 404 Media.

Flock Safety operates a national network of cameras that capture and store license-plate data, vehicle make and model, and timestamp information. Law enforcement agencies subscribe to the service and can query the database or set automated alerts for specific plates.

Officers used the tracking data to position themselves for an intercept, then cited a minor traffic infraction as the stated basis for the stop. The subsequent search yielded cannabis.

The surveillance preceded the stated justification for the stop by hours, raising questions about whether the traffic violation was pretextual under Whren v. United States and subsequent Fourth Amendment case law.

Fourth Amendment Implications for Cannabis Enforcement

The case tests whether prolonged, warrantless geolocation tracking via third-party cameras constitutes a search under Carpenter v. United States, 585 U.S. ___ (2018). In Carpenter, the Supreme Court held that accessing seven days of cell-site location data required a warrant because it revealed an intimate picture of a person's life.

Flock camera networks can reconstruct travel patterns across days or weeks. Defense attorneys in cannabis cases have begun challenging these searches. They argue that aggregated ALPR data functions as continuous GPS monitoring, a practice the Court restricted in United States v. Jones, 565 U.S. 400 (2012).

No federal appellate court has yet ruled definitively on whether Flock-derived tracking requires a warrant. The issue is working its way through district courts, particularly in states where cannabis possession remains a felony.

Implications for State-Legal Cannabis Programs

Interstate cannabis enforcement using surveillance technology complicates state-legal markets, where patients and operators routinely cross state lines. Medical cardholders traveling from Ohio to Michigan dispensaries, or California cultivators transporting clones to Oregon, generate ALPR records that can be queried by any subscribing agency.

For full background on this story, see the CannIntel topic hub on Cannabis Surveillance and Civil Liberties.

A suppression hearing on the search is the next procedural step. If the court grants the motion, the evidence—and any derivative evidence—will be excluded under the fruit-of-the-poisonous-tree doctrine. That ruling would set precedent for similar Flock-assisted stops in the jurisdiction.