Crime analyst Andrew Wheeler has argued that police should obtain warrants before searching stored automatic license plate reader records, while retaining the ability to use cameras for immediate alerts. His proposal separates the collection and short-term preservation of plate data from the legal authority to trace a vehicle's historical movements.
Wheeler works with police departments and served as an expert witness for the Institute for Justice in `Schmidt v. City of Norfolk`, a case concerning whether searches of cached ALPR information were unlawful. The judge ruled against the plaintiffs, finding that Norfolk's system had not yet crossed the constitutional threshold for overly intrusive mass surveillance, while acknowledging that such a point could eventually be reached.
An active alert checks a passing plate against a list, for example to identify a stolen vehicle. Wheeler says that function does not require a lasting archive. A historical query is different: an investigator can enter a plate and retrieve timestamps and locations recorded over days or weeks. Dense coverage can reveal repeated destinations and likely sleeping locations.
He compares that capability with cell-site location information addressed by the United States Supreme Court in `Carpenter v. United States`. Warrants are required for comprehensive historical cell-location records even though private companies hold them. Wheeler also points to decisions involving geofence data and historical aerial surveillance as signs that increasingly complete movement records attract constitutional protection.
His position is not anti-camera. Wheeler says plate readers are relatively inexpensive, at under $3,000 per camera, and may provide a positive return if each helps clear a small number of cases. He describes the evidence that they reduce crime as limited, but expects public and private camera coverage to become increasingly common.
Deleting data immediately is not his preferred safeguard. That approach can remove information needed for legitimate investigations without preventing an officer from making an improper query while records exist. Wheeler instead favors preserving useful data while requiring judicial authorization for retrospective searches and improving audit controls. He characterizes existing protections against misuse as inadequate.
The proposal is an expert's policy argument, not a statement of current law in every jurisdiction. Wheeler recommends state statutes because they can establish a clear warrant process before camera networks become comprehensive enough to force a new constitutional ruling. The intended balance is continued real-time detection, accountable access to history and a record-retention policy that serves investigations without allowing unrestricted location tracking.
Wheeler presents warrants as a procedural boundary rather than a ban on evidence. Investigators could still seek stored results when they establish legal grounds, and departments would retain the audit trail needed to examine who searched for what.
