Know when police gear is near — anywhere in South Dakota.
From Sioux Falls (pop. 171,544) across all 50 of its biggest cities, South Dakota law-enforcement gear broadcasts Bluetooth and Wi-Fi signatures everywhere it goes. Cop Spotter listens for them — green means clear, red-and-blue means near.
Built in small batches. No subscription. No account.
Coverage across the state.
Pick your city for local coverage.
Minnehaha County · pop. 171,544
Pennington County · pop. 73,569
Brown County · pop. 28,102
Brookings County · pop. 23,657
Codington County · pop. 22,073
Davison County · pop. 15,669
Yankton County · pop. 14,557
Hughes County · pop. 14,091
Beadle County · pop. 13,313
Lawrence County · pop. 11,283
Clay County · pop. 10,738
Minnehaha County · pop. 9,856
Pennington County · pop. 9,289
Pennington County · pop. 8,260
Pennington County · pop. 8,000
Lake County · pop. 7,258
Meade County · pop. 6,688
Butte County · pop. 5,696
Lincoln County · pop. 5,498
Lincoln County · pop. 4,839
Minnehaha County · pop. 3,706
Fall River County · pop. 3,532
Walworth County · pop. 3,466
Lincoln County · pop. 3,331
Oglala Lakota County · pop. 3,308
Grant County · pop. 3,192
Minnehaha County · pop. 3,025
Lawrence County · pop. 2,999
Meade County · pop. 2,892
Tripp County · pop. 2,825
Union County · pop. 2,731
Union County · pop. 2,540
Pennington County · pop. 2,493
Roberts County · pop. 2,450
Brule County · pop. 2,386
Spink County · pop. 2,379
Moody County · pop. 2,303
Lawrence County · pop. 2,285
Lincoln County · pop. 2,272
Meade County · pop. 2,239
Stanley County · pop. 2,117
Union County · pop. 2,075
Union County · pop. 1,976
Dewey County · pop. 1,954
Bon Homme County · pop. 1,953
Custer County · pop. 1,952
Brookings County · pop. 1,865
Day County · pop. 1,802
Charles Mix County · pop. 1,589
Todd County · pop. 1,587
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 across South Dakota.
Yes — it needs no network, app, or account. The signatures it matches are the same in Sioux Falls as in the smallest town in South Dakota.
$50 one time — shipping included (U.S.), no tax added, no subscription, ever.
The 50 biggest cities in South Dakota — listed below. The detector itself works anywhere in the state, page or no page.
Bodycams, Tasers, Flock camera accessories, radio gear, in-car video systems, police drones, LIFEPAK monitors, patrol-car routers, fleet telematics, hidden trackers, and skimmer modules — 103 verified hardware fingerprints.
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.