# SignalTrace Electronic-Signature Tracking SignalTrace is a Leonardo/ELSAG product that the vendor says detects patterns and identifiers emitted by nearby electronics, groups recurring device combinations into an “electronic signature,” and can correlate that signature with a vehicle plate when LPR observations are available. It is a separate sensor and analytics modality from ordinary plate recognition. ## Vendor-described capability Leonardo says the system can observe signals associated with mobile phones, watches, fitness trackers, RFID tags, and other electronics; group devices that travel together; associate a group with a plate at a common time and place; and later query or alert on the group even when a plate is not visible. The vendor also markets operation in off-road or mixed-use settings such as subways and malls and says an LPR need not be present at every collection point (vendor primary/self-description, [SignalTrace product page](../../web%20archive/2026-07-20/leonardocompany-us.com/elsag-signaltrace.md); [SignalTrace product sheet](../../web%20archive/2026-07-20/leonardocompany-us.com/signaltrace-product-sheet.md)). Leonardo says SignalTrace does not decrypt or read communication content. That is a content boundary, not an anonymity guarantee: repeated co-travel, rare device combinations, and plate correlation can make metadata highly identifying. Device churn, identifier randomization, passengers, borrowed vehicles, rideshare trips, common devices, powered-off radios, and coverage gaps also create plausible split, collision, false-association, and miss mechanisms. No independent public precision/recall or false-association benchmark was located. ## Patent boundary The associated patent describes possible electronic-signature, wireless-observation, likelihood, and plate-correlation embodiments. It establishes what the patent claims disclose; it does not prove that every marketed or deployed SignalTrace system implements every embodiment (primary public record, [US 11,941,716 B2](../../web%20archive/2026-07-20/image-ppubs.uspto.gov/us11941716b2.md)). ## Arkansas and Flock boundaries ASP's Tier-1 procurement establishes purchases of Leonardo/ELSAG ALPR products, HIDTA licensing, and related services ([[Term Contract 4600055190 and PO 4502235324 — Initial Leonardo ELSAG Buy]]). It does **not** name SignalTrace. The later vendor correspondence likewise documents ELSAG coordination and sales activity, not a SignalTrace order ([[Leonardo ELSAG Vendor Coordination and Procurement]]). No official source located in this audit establishes a Flock-SignalTrace integration. Shared corporate/vendor context or the technical possibility of plate correlation must not be converted into such a claim. ## Open questions - Has any Arkansas agency received a SignalTrace presentation, demonstration, quote, trial, contract, privacy assessment, or legal review? - If so, what radio categories, identifier transformations, retention, plate correlations, locations, user permissions, audits, error tests, and sharing paths are configured?