Know when police gear is near in Union City — before you see it.
Union City is a city of 69,156 in Hudson County, New Jersey. Its officers, troopers, and medics carry gear that constantly broadcasts Bluetooth and Wi-Fi signals so docks and cars can find it. Cop Spotter listens for those signatures. Green light means clear. Red-and-blue strobe means gear is close.
Built in small batches. No subscription. No account.
The place, in real numbers.
Also covered near Union City: West New York (1 mi), North Bergen (2 mi), Hoboken (2 mi), Jersey City (5 mi) — and all 50 of the biggest cities in New Jersey.
The signature database is built from public registries — Bluetooth SIG company IDs, IEEE hardware prefixes, and the known broadcast fingerprints of the gear itself.
Axon body cameras announce themselves over Bluetooth so docks can find them — including a hardware signature that survives the address rotation newer cameras use to hide. If a bodycam is close, Cop Spotter knows.
Tasers and Axon vehicle gear broadcast their own Bluetooth identities. Same family, same tell — the spotter matches them against the verified Axon signature set.
Flock safety-camera accessories — extended batteries, setup hotspots — leak recognizable Bluetooth names and Wi-Fi hardware prefixes. Cop Spotter watches both radios.
Modern police radios carry Bluetooth for mics and earpieces, and their hardware shows up in the air with manufacturer fingerprints. A radio match strobes the light exactly like every other gear type — nothing is second-class.
AirTags, SmartTags, Tiles and other tracking tags call home over Bluetooth. Cop Spotter listens for them too — when one is close enough to be traveling with you, the light pulses purple, and the pulse quickens as you get closer, so you can walk it down.
Skimmers hidden inside pumps and card readers phone home through cheap Bluetooth serial modules — and those modules advertise. When one is close, the light blinks amber before your card goes in.
Also in the database: Utility BodyWorn bodycams, Axon Fleet in-car systems, WatchGuard & Digital Ally in-car video, police drones (DJI and anything flying Remote ID), Stryker LIFEPAK ambulance monitors, Cradlepoint patrol-car routers, and Geotab fleet telematics — 103 verified hardware fingerprints in all.
No screen to read. One light tells you everything.
The board continuously scans Bluetooth and Wi-Fi broadcasts — the public advertisements devices send out so other equipment can discover them.
Every broadcast is checked against the signature database: company IDs, service UUIDs, hardware prefixes, and device names known to belong to police equipment, tracking tags, and skimmer hardware.
When a signature matches, the light answers in color — every gear type counts, radios included. Cooldowns between alerts keep the light meaningful instead of constant.
No modes, no menus — Cop Spotter listens for everything at once, and the color names what it heard.
Purple and amber only fire at close range — close enough to be on you or your car — so a crowd full of other people’s trackers doesn’t cry wolf.
Asked by buyers in Union City and across New Jersey.
Yes. Police gear broadcasts the same Bluetooth and Wi-Fi signatures everywhere — Union City, New Jersey included. Bodycams, Tasers, Flock cameras, radios, and patrol-car routers all announce themselves the same way here as anywhere else.
$50 one time — shipping included (U.S.), no tax added at checkout, no subscription. A Union City order costs exactly the same as any other.
The full database: Axon bodycams, Tasers and Axon Fleet, Flock camera accessories, Motorola radio gear, WatchGuard & Digital Ally car video, Utility BodyWorn, police drones on Remote ID, Stryker LIFEPAK monitors, Cradlepoint routers, and Geotab telematics — plus hidden trackers (AirTag, SmartTag, Tile) and skimmer-class Bluetooth modules — 103 verified hardware fingerprints in all.
Cop Spotter is receive-only: it listens to public broadcast advertisements devices send out for discovery. It does not intercept, decrypt, record, or transmit anything. Rules around detection equipment vary by place, so know your local laws — the responsibility for where and how you use it is yours.
Every covered city in the state.
Essex County · pop. 281,944
Hudson County · pop. 264,290
Passaic County · pop. 147,754
Union County · pop. 129,007
Middlesex County · pop. 102,548
Mercer County · pop. 89,620
Ocean County · pop. 88,791
Passaic County · pop. 86,334
Camden County · pop. 76,119
Ocean County · pop. 76,021
Passaic County · pop. 71,085
Camden County · pop. 70,475
Hudson County · pop. 66,311
Monmouth County · pop. 65,490
Essex County · pop. 64,949
Hudson County · pop. 63,484
Essex County · pop. 61,323
Cumberland County · pop. 60,818
Cumberland County · pop. 58,122
Passaic County · pop. 57,915
Middlesex County · pop. 57,035
Union County · pop. 56,771
Middlesex County · pop. 56,044
Camden County · pop. 54,856
Ocean County · pop. 53,805
Hudson County · pop. 53,635
Hudson County · pop. 53,366
Middlesex County · pop. 52,682
Union County · pop. 51,217
Morris County · pop. 51,144
Essex County · pop. 49,120
Middlesex County · pop. 48,495
Essex County · pop. 48,131
Middlesex County · pop. 44,920
Bergen County · pop. 44,834
Somerset County · pop. 44,464
Middlesex County · pop. 43,905
Camden County · pop. 42,891
Middlesex County · pop. 42,890
Hudson County · pop. 42,137
Union County · pop. 42,021
Burlington County · pop. 41,864
Monmouth County · pop. 40,191
Bergen County · pop. 40,078
Essex County · pop. 39,701
Atlantic County · pop. 39,260
Somerset County · pop. 38,303
Gloucester County · pop. 37,433
Essex County · pop. 36,878
Small batches, built to order.
The detector board, with the detection firmware loaded and the signature database installed. You add any USB-C power source — a power bank makes it pocket carry.
Buy now — $50Secure checkout via Stripe — shipping included, address collected at checkout (U.S.). Questions first? [email protected]
The same detector on your Android phone — all 103 signatures. It listens only, holds no internet permission, and collects nothing. Free, no account; the APK installs direct.
If it earns its keep, chip in: support goes straight into the next batch of boards.
Receive-only, by design. Cop Spotter listens to public broadcast advertisements that devices intentionally transmit for discovery. It does not intercept, decrypt, record, or interfere with any communication, and it transmits nothing.
Know your local laws. Rules around detection equipment vary by place. What the device does is legal in most of the U.S., but the responsibility for where and how you use it is yours.
No guarantees. Detection depends on the target gear being powered and advertising. This is an awareness tool, not a safety device.