Phony "Fugitive Task Force" Busted

[patric]

A trio of bounty hunters hired by a landlord to forcibly evict some tenants were arrested for impersonating federal agents.
They were not only armed, wearing police uniforms and badges, but were using the McAlester Police radio system to obtain warrant information and call for "backup".

http://www.fox23.com/mostpopular/story/Three-arrested-for-impersonating-law-enforcement/XgnzhUvSs0CC3GyYuM_p0g.cspx

[Ed W]

In addition to state charges, they could be charged with interfering with a legitimate emergency communication frequency.  That's a federal charge.  It's been used previously when unauthorized people use emergency frequencies.

[dbacks fan]

Was this them?

[patric]

Was this them?

Not as ugly.
Is he attempting to deflate her?

In addition to state charges, they could be charged with interfering with a legitimate emergency communication frequency.  That's a federal charge.  It's been used previously when unauthorized people use emergency frequencies.

Dont you need encryption keys from someone in the department?

[Ed W]

There are several different ways to encrypt FM radio communications.  The simplest is a sub-audible tone.  This is usually in the lower audio frequency range.  The transmitter puts out a 85Hz tone at a level well below the transmitted voice.  The receiver detects the tone, and uses it to pass the audio on to the amplifier and speaker.  Without the tone, the receiver rejects the audio.  This is the scheme used in those popular GMRS or FRS radios.

Another simple encryption technique is called frequency inversion scrambling.  Audio in the 300-3000Hz range is mixed with a 8KHz carrier, forming two sidebands.  One is at 8.3 to 11KHz, the other at 5 to 7.7KHz.  The upper sideband is filtered out before transmission.  On the receiver end, the process is reversed, mixing the lower sideband with a 8KHz tone and filtering out the unwanted audio products.  This used to be done with cumbersome LC circuits, but it's much more easily accomplished with ICs. It's still obviously a voice, but it's not intelligible.

Things get more complicated with trunked radio systems like Tulsa's.  There are 20 discrete frequencies, with 4 set aside as data channels.  Each radio is assigned a group code, identifying it for the type of service.  So Uniform Division North has a unique code, as does the dog catcher, bus drivers, and trash collector.  They don't hear each other at all.  Further, the trunk tracker keeps tabs on who talks to who, and sees that their communications track each other even if the system keeps changing frequencies. Typically, they stay on one frequency for each transmission.

Some tactical units have digitally encrypted radios that sound like static.  I've only heard them a few times, but the transmission is not recognizable as a voice.  I realized what they were due to other unencrypted traffic about a hostage situation developing across the street from a friend's house.

Finally, there are some radios that offer both digitally encrypted audio and the capability for frequency hopping in 100mSec intervals.  They change frequency every tenth of a second.  In order to communicate, both transmitter and receiver need to have the same codes installed and be synchronized.  I've seen just one of these radios, and of course, I couldn't tinker with it.  The set came in three parts: a fold up antenna not unlike a small umbrella, the transceiver, and a power supply that was designed to work with any voltage source on the planet.  The whole thing would fit in a brief case.  It came with a simple slide rule type calculator that assisted with aiming the antenna at the right satellite.  The guys who use them are known to eat snakes.   

[AquaMan]

Ed....you're scaring me man. Adderal?

[Ed W]

Ed....you're scaring me man. Adderal?

Remember...I'm a professional electronics geek, an amateur radio operator (N5SNW), and an obsessive reader.  I read candy bar wrappers and cereal boxes.  Nothing escapes.

Hey, look at those black framed glasses.  They're a sure-fire sign of a techno-geek of some sort!

[AquaMan]

Hey, I had coffee with you. You don't look like that anymore, in fact, you look middle aged cool with old school camera in hand and not afraid to use it!

Not too late to go in to politics you know. We've had doctors, actors, football players, basketball players, Navy Seals and such. Why not the world's first Geek Governor?

Anyway, back on topic. How easy is it to get the paraphernalia to imitate a McAlester cop? I had some experience down there in buying a boat. When the deal started to go bad, the seller threatened to have his cousin, the Sheriff of something or other come escort me to court. I got the feeling he wasn't kidding. Lots of intrigue in that area.

[RecycleMichael]

Theree are currently 8.000 plus police badges for sale on Ebay.

http://www.ebay.com/sch/items/__police-badges_W0QQ_nkwZpoliceQ20badgesQQQ5ftrkparmsZ72Q253A1205Q257C39Q253A1Q257C66Q253A2Q257C65Q253A12QQ_trksidZp3286Q2ec0Q2em14QQ_pgnZ16

[patric]

They weren't listening in on a scanner, they were talking back and forth on the main frequency as if they were LEOs.  So, did someone give them the group codes?

[dbacks fan]

McAlester Police are still using 150mhz radios which are not trunking radios. Here is a list of their frequencies:

155.71500  KYI993  RM 110.9 PL McAlestrPD S  McAlester Police Dispatch (South Repeater)  FM  Law Dispatch 
155.61000  KGQ491  BM 114.8 PL McAlestrPD N  McAlester Police (North Repeater)  FM  Law Tac 
153.26000    M  McAlesterPD7  McAlester Police (Channel 7) -- Car-to-Car  FM  Law Tac 
45.64000    BM  McAlesterPD9  McAlester Police (Channel 9) -- Tactical  FM  Law Tac 
155.74500  KYI993  BM 146.2 PL McAlester PW  McAlester Public Works  FM  Public Works 
155.76000  KNBL318  BM  MutalAid760  McAlester Public Works  FM  Interop 
155.94000  KYI993  BM 203.5 PL McAlestrWatr  McAlester Water Department  FM  Public Works

http://www.radioreference.com/apps/db/?ctid=2188

[patric]

McAlester Police are still using 150mhz radios which are not trunking radios.

You only listed VHF and Low Band, they have 800Mhz which are usually trunked:

855.21250     WPUE966     RM    123.0 PL    PitsCoSO-Cen    Pittsburg County Sheriff -- McAlester     FM     Law Tac
855.23750     WPUE966     RM      PitsCoSO-Sou    Pittsburg County Sheriff -- South Part of County     FM     Law Tac
855.46250     WPUE966     RM      PitsbCoSO-NE    Pittsburg County Sheriff -- Northeast Part of County     FM     Law Tac
855.48750     WPUE966     RM    025 DPL    PitsCoSO-Wst    Pittsburg County Sheriff -- West Part of County     FM     Law Tac

[dbacks fan]

I was basing my comment on the statement that they were using radios on the PD freq which in the 150mhz range is easier to do. I did notice that several leo's in the area are using 800 trunking which is harder but not impossible to do. At any rate, it sounds like some wannabe's acting like thugs.

[custosnox]

Yet another to add to the list of reasons why Bounty Hunters need to be licensed in this state.

[patric]

Another simple encryption technique is called frequency inversion scrambling.  Audio in the 300-3000Hz range is mixed with a 8KHz carrier, forming two sidebands.  One is at 8.3 to 11KHz, the other at 5 to 7.7KHz.  The upper sideband is filtered out before transmission.  On the receiver end, the process is reversed, mixing the lower sideband with a 8KHz tone and filtering out the unwanted audio products.  This used to be done with cumbersome LC circuits, but it's much more easily accomplished with ICs. It's still obviously a voice, but it's not intelligible.

About the time you posted this drift, I noticed Rogers County is still using inversion scrambling.

Wow, what a blast from the past... I can remember as a teenager building ring modulators for scanner buffs so they could break the encryption.  Radio Shacks were a lot more useful then. 
Most agencies were realistic about it (that scrambling only excluded all but the determined) and other than hardware (and now software) the philosophy is the same today.