Hello.
I am in San Antonio, TX, where a new radio system is to be installed.
This is to be the GE/Ericsson/Tyco/whoever is next system.
The problem is, drug traffic trade people are concerned with not being able to monitor the new system, at least not at first, and "they" are willing to pay $$$ for information.
There have been some major busts, in local government as well as police.
What I would like to know is, do you feel this to be a problem in your area, what can be done about it, is it really that much of a problem?.
The present system 'Smartnet' has no security, it has been totally hacked, however I have decoded the "new" systems test messages, and this was in secure mode.
The MDTs are going to CPDP, not really secure, but better than MDC.
Am I spending too much time trying to stop something that is going to happen anyway?.
The Drug Dealers
Moderator: Queue Moderator
More than 99% of the traffic that passes over a police radio system is not tactically or operationally sensitive. The 1% of so that is sensitive is carred, in my neck of the woods, over Nextels. The Nextels either have the phone privilege disabled or billed directly to the officer, which minimizes abuse (and the resultant cost), and so the whole thing works pretty well.
From an operational perspective, Nextel is just an 800 MHz SMRS, except that it uses the Iden format, involves a digital audio format (a la Astro) that cannot be read by an analog receiver (even if you happen on the voice channel), and tends to use cells of such a limited range that intentional interception would be difficult (at the least) even if the voice were analog.
Nextels are, in the scheme of things, more expensive than most cellular or PCS mobile phones, but the cost is a mere fraction of the cost of building out an Astro or encrypted owned system that, 99% of the time, there is no need for.
From an operational perspective, Nextel is just an 800 MHz SMRS, except that it uses the Iden format, involves a digital audio format (a la Astro) that cannot be read by an analog receiver (even if you happen on the voice channel), and tends to use cells of such a limited range that intentional interception would be difficult (at the least) even if the voice were analog.
Nextels are, in the scheme of things, more expensive than most cellular or PCS mobile phones, but the cost is a mere fraction of the cost of building out an Astro or encrypted owned system that, 99% of the time, there is no need for.
with as much money as they have to throw at the problem . you will never have a secure system even if you had the best encription in the world .... you will have dirty cops that will " give " them all the info that they will ever want with a phone call 
digital radios with encripton . over the air rekey and trunking will slow down the " little fish " and the wanna bees
but the guys that are making millions of dollars a year on selling drugs across the border will always have enough money to buy all the wiz bang things to break whatever code you can design ... and if that dont work . they will just pay off some dirty cop and get what the need that way...
happens every day .....
digital radios with encripton . over the air rekey and trunking will slow down the " little fish " and the wanna bees
but the guys that are making millions of dollars a year on selling drugs across the border will always have enough money to buy all the wiz bang things to break whatever code you can design ... and if that dont work . they will just pay off some dirty cop and get what the need that way...
happens every day .....
Secure Coms
Is this gonna be a digital provoice system or aegis system??? Also the only way to obtain the secure encryption is for someone to either write them down and give out, or load a radio. Once the key is loaded in a KVL its unretrievable. Your selection of who and how often you reload the keys is most important. Access to the KVL or Console is one of the most important things. The amount of equipment and time, it would take to break the code, is not gonna be available except to your heaviest hitters.
Another option is that when you do limited or time related ops, you have a selected position or talkgroup for that code and it is loaded then and only to the units involved, and then flushed from the loader. We use Motorolas so there is selectable key retention and the only way to compromise is by loosing a radio, which results in an mandated rekey.
Another agency also has the same thing. Key is called Day2Day, Key 2 is OPS 1 and changes constantly. Its interesting because we have never had a compromised key and thats coming the the Drug Capital of the south ... South Florida.. aka th Banana republic. If you actually follow the proper protocols 95% of what was mentioned here can't happen. Ps the Nextel thing is interesting, because they a lot more easily compromised than you think, they suck for surveillance with more than 2 people and at 7:30-9:00Am and 4:-7:00PM you gonna be lucky to get on down here without a lot of breaks, drops and busy signals. I realize coverage and loading may be better in some areas and budget wise also, so if it works for you ... There are some other little tricks you can play also. Speaking Klingon can really throw them of....
Another option is that when you do limited or time related ops, you have a selected position or talkgroup for that code and it is loaded then and only to the units involved, and then flushed from the loader. We use Motorolas so there is selectable key retention and the only way to compromise is by loosing a radio, which results in an mandated rekey.
Another agency also has the same thing. Key is called Day2Day, Key 2 is OPS 1 and changes constantly. Its interesting because we have never had a compromised key and thats coming the the Drug Capital of the south ... South Florida.. aka th Banana republic. If you actually follow the proper protocols 95% of what was mentioned here can't happen. Ps the Nextel thing is interesting, because they a lot more easily compromised than you think, they suck for surveillance with more than 2 people and at 7:30-9:00Am and 4:-7:00PM you gonna be lucky to get on down here without a lot of breaks, drops and busy signals. I realize coverage and loading may be better in some areas and budget wise also, so if it works for you ... There are some other little tricks you can play also. Speaking Klingon can really throw them of....
HI:
In the world where I am, when a special ops is { in order }
they have a simple team ( as that is how most major busts )
are made, and the team is outfitted with encryption which makes
is almost if not completely impossible for the drugges to listen
in.
The [ only ] way that can be breached if there is a breach
in the ops, which is pretty rare in my opinion.
But even the best laid pipes with millions of dollars being spent,
can develope leaks.
Next ops, just change the encryption keys !!
MS
In the world where I am, when a special ops is { in order }
they have a simple team ( as that is how most major busts )
are made, and the team is outfitted with encryption which makes
is almost if not completely impossible for the drugges to listen
in.
The [ only ] way that can be breached if there is a breach
in the ops, which is pretty rare in my opinion.
But even the best laid pipes with millions of dollars being spent,
can develope leaks.
Next ops, just change the encryption keys !!
MS
-
Salem The Cat
- Posts: 74
- Joined: Mon Sep 03, 2001 4:00 pm
Legalize it, regulate it, and tax it
99% of your "drug dealer" problems will disappear.
I object to my tax dollars funding the "war on drugs",
when all it really is, is perpetuating a stereotype of a
knight in shining armor (ie. law enforcement), coming
to the rescue of those who choose not to use drugs.
Anyone hear of Prohibition ? I think I can speak with
some authority, considering one of my family used to
be a moonshine runner down south. Made a lot of $$,
but when prohibition was lifted, the market vanished
almost immediately. Why bother going underground,
when you can get it legally in a store ?
Same with prostitution, legalize it the way certain states
have. Who gives a rats ass ? What's the difference between
paying some bimbo $25 bucks up front, or taking her out
to dinner ?
The unsavory characters associated with underground
activities are what fuel the violence in the drug dealing
arena. Bring it out into the open, into the realm of federal
regulators (a la Tobacco, and Alcohol) and tax it, license
it, and let people abuse themselves to death....Darwinian
law at work....no different than the losers who drink or
smoke themselves to oblivion.
The "unsavory characters" I speak of are not limited to
the drug dealing miscreants. Law enforcement is just as
violent and arrogant. What other excuse is there for an
armed federal agent to slam a 80 yr old grandmothers
face into a concrete sidewalk while pointing an HK MP-5
at the back of her head ?
There is something inherently wrong when a "drug dealer"
who's only crime (under current law) was to be caught with
x grams of cocaine, being sentenced to life in prison -
meanwhile a serial murderer/rapist is given 5 yrs and out
on parole in even less time. The federal prison system is
out of control with "drug offenders" behind bars - (more than
65% of the inmates) - only a small percentage are in there
for violent crimes.
Great use of our tax dollars !
99% of your "drug dealer" problems will disappear.
I object to my tax dollars funding the "war on drugs",
when all it really is, is perpetuating a stereotype of a
knight in shining armor (ie. law enforcement), coming
to the rescue of those who choose not to use drugs.
Anyone hear of Prohibition ? I think I can speak with
some authority, considering one of my family used to
be a moonshine runner down south. Made a lot of $$,
but when prohibition was lifted, the market vanished
almost immediately. Why bother going underground,
when you can get it legally in a store ?
Same with prostitution, legalize it the way certain states
have. Who gives a rats ass ? What's the difference between
paying some bimbo $25 bucks up front, or taking her out
to dinner ?
The unsavory characters associated with underground
activities are what fuel the violence in the drug dealing
arena. Bring it out into the open, into the realm of federal
regulators (a la Tobacco, and Alcohol) and tax it, license
it, and let people abuse themselves to death....Darwinian
law at work....no different than the losers who drink or
smoke themselves to oblivion.
The "unsavory characters" I speak of are not limited to
the drug dealing miscreants. Law enforcement is just as
violent and arrogant. What other excuse is there for an
armed federal agent to slam a 80 yr old grandmothers
face into a concrete sidewalk while pointing an HK MP-5
at the back of her head ?
There is something inherently wrong when a "drug dealer"
who's only crime (under current law) was to be caught with
x grams of cocaine, being sentenced to life in prison -
meanwhile a serial murderer/rapist is given 5 yrs and out
on parole in even less time. The federal prison system is
out of control with "drug offenders" behind bars - (more than
65% of the inmates) - only a small percentage are in there
for violent crimes.
Great use of our tax dollars !
-
mavericknet
- Posts: 235
- Joined: Mon Jan 28, 2002 4:00 pm
- What radios do you own?: HT1250 VHF, CDM1550 UHF
Umm...
I don't even know quite how to rationalize Salem the Cat's think in total, but some of what he says makes sense. True if you legalize drugs, then there will be a decrease in the amount of drug dealer crime. However, those who are/become dependant are going to still be out committing crime, sometimes violet to be able to pay the corner drug store for a fix they can now go down and get all the time. I don't know about you, but I don't want a car with an Astro Saber sitting in the dash sitting next to one of those stores. Somebody tried to make off with a pair of maxtracs out of a f/r outside the methedone clinic. I think the best way to take care of the problem is to really wage war, not this wussy crud they're doing, go out and kick some ass. Jails aren't here to hold drug dealers, you'll find having to pay hospital bill will hurt drug dealers more than a 5 year all-expenses-paid stay in a prison. But my current views on the poor state of our rehabilitation/prison system aside, I think police band monitoring is a great thing. I think it's a terrible thing when someone can use it to take action against the police., White shining armor or not, the police are here to protect, they do a hell of a job, they don't need some nutball who's been robbing places to know they're out on their lunch break. Anyway, my $.02 and I'm stickin to it.
Secure comms
Yeah lets see , the basic drug user isn't gonna steal because he will have a job... from whom???... since your kidding yourself if you think industry is gonna hire anyone that has a drug problem.. due to the risk of their poor productivity, health and other issues and the insurance companies and attorneys are gonna cost you more than the government, and of course depending on how you distribute the drugs... no drug user ( try very habit forming in most cases) is ever gonna knock off or steal from another user , or from Joe public to pay for it oh and not buy it on the blackmarket.... even more profitable area for the dealers if its limited...and there will still be dealers......
You can't even hand over a box of steroids and say only take two of these a day, without the idiot taking 10 for more gratifying results, quicker and faster. And are we gonna make the drug user promise to stay at home and not go out till all the effect of the drug use are gone... yeah thats gonna happen...but if you are so sure you could control it... Prohibition was one of the worst mistakes of the century, lets not start a new one. PS if you wanna do this we should probably order all of our stuff from oversea's. Oh and lets not forget the transportation industry.. airlines, trucks, trains.. cause if you wanna legalize it we can't be guilty of discrimination. And the Unborn Baby Coalition thats gonna be lining up to sue the parents, and will need the health care cause they'll be all screwed up. And yes there are a lot of things that Law Enforcement and Government do that are both shameful but also correctible, but you are kidding yourself in more than one way both with the arguement , the logic and last but not least the futility of the arguement. That being said I'll go back to just the radio and other stuff here on the board.
You can't even hand over a box of steroids and say only take two of these a day, without the idiot taking 10 for more gratifying results, quicker and faster. And are we gonna make the drug user promise to stay at home and not go out till all the effect of the drug use are gone... yeah thats gonna happen...but if you are so sure you could control it... Prohibition was one of the worst mistakes of the century, lets not start a new one. PS if you wanna do this we should probably order all of our stuff from oversea's. Oh and lets not forget the transportation industry.. airlines, trucks, trains.. cause if you wanna legalize it we can't be guilty of discrimination. And the Unborn Baby Coalition thats gonna be lining up to sue the parents, and will need the health care cause they'll be all screwed up. And yes there are a lot of things that Law Enforcement and Government do that are both shameful but also correctible, but you are kidding yourself in more than one way both with the arguement , the logic and last but not least the futility of the arguement. That being said I'll go back to just the radio and other stuff here on the board.
-
Salem The Cat
- Posts: 74
- Joined: Mon Sep 03, 2001 4:00 pm
Well, let's see amidst the inflammatory and erroneous stereotypes
regarding the unknown consequences of legalizing drugs (be it pot
or whatever) - your rant makes absolutely no sense.
In one sentence you assert the ending of Prohibition was a sound
end to a failed experiment. Then the claim is, drugs are somehow
different from alcohol or tobacco.
How so ? You mean the social ills from alcohol (DUI, domestic
violence, etc), are less serious than the "drug problem" ? At least
with alcohol, it's being taxed and regulated. The job of the govt
is not to dictate to the fools who abuse the freedom of that legality.
Oh, and it's fairly obvious you harbor a holier-than-thou
attitude regarding the users/abusers/players of the drug
trade. Yeah, they're cockroaches, so are mob thugs like
tony soprano. The inherent hypocrisy in admiring one (by
providing them ratings), while deriding the other, is quite
an affirmation of how backwards a society we've become.
But you're correct we digress from radios. So suffice it to say,
if I want to compromise one of todays systems. I will not seek
a technical (ie. SIGINT) means. Much more effective to be a grunt
using HUMINT intel collection (w/ some persuasion from Ben's
pictures).
regarding the unknown consequences of legalizing drugs (be it pot
or whatever) - your rant makes absolutely no sense.
In one sentence you assert the ending of Prohibition was a sound
end to a failed experiment. Then the claim is, drugs are somehow
different from alcohol or tobacco.
How so ? You mean the social ills from alcohol (DUI, domestic
violence, etc), are less serious than the "drug problem" ? At least
with alcohol, it's being taxed and regulated. The job of the govt
is not to dictate to the fools who abuse the freedom of that legality.
Oh, and it's fairly obvious you harbor a holier-than-thou
attitude regarding the users/abusers/players of the drug
trade. Yeah, they're cockroaches, so are mob thugs like
tony soprano. The inherent hypocrisy in admiring one (by
providing them ratings), while deriding the other, is quite
an affirmation of how backwards a society we've become.
But you're correct we digress from radios. So suffice it to say,
if I want to compromise one of todays systems. I will not seek
a technical (ie. SIGINT) means. Much more effective to be a grunt
using HUMINT intel collection (w/ some persuasion from Ben's
pictures).
Secure comms
I'm not even gonna attempts to answer this cause it would fill volumes, drugs in of themselve from MJ to OXy vary, alchohol is a drug, people can't control that and its the minor end of the scale, there are a lot of variables.
But you hit on an excellent point on Secure comms, and many in other aspects of intelligence, people are the weakness, excellent example is the Walker family... We had good security with our technology but the human element compromised it. We had a fellow agency down the way that I could walk into their meeting room and they always left the freakin info on the blackboard of the sting, search warrant, or surveillance on the board, after they had left, in an open unsecured area that the janitor and all the other staff passed thru to get to the breakroom and bathrooms.
.... "we are the weakest link"
But you hit on an excellent point on Secure comms, and many in other aspects of intelligence, people are the weakness, excellent example is the Walker family... We had good security with our technology but the human element compromised it. We had a fellow agency down the way that I could walk into their meeting room and they always left the freakin info on the blackboard of the sting, search warrant, or surveillance on the board, after they had left, in an open unsecured area that the janitor and all the other staff passed thru to get to the breakroom and bathrooms.
.... "we are the weakest link"
-
mavericknet
- Posts: 235
- Joined: Mon Jan 28, 2002 4:00 pm
- What radios do you own?: HT1250 VHF, CDM1550 UHF
I liked prohibition
I wish prohibition was still around, I find alcohol to be a great offender... ciggarettes as well. However I've watched people, good friends that are dead now because they needed more drugs... They couldn't help it, they were peer pressured teenagers, they were hooked, and now they're in a pine box. Say what you will about stereotypes, I hope that dealer rots in whatever form of hell he/she believes in.
I have met people of questionable intent that have access to scanners, most of the stuff out here is in analog format and out in open on VHF, a guy eluded a three hour pursuit's roadblocks by knowing where to turn.
I have met people of questionable intent that have access to scanners, most of the stuff out here is in analog format and out in open on VHF, a guy eluded a three hour pursuit's roadblocks by knowing where to turn.
Just a Viewpoint:
Its Ironic that persons will spend 100's sometimes
1000's of dollars in Upgrading their Computer, Improving
its Memory, Scandisc, defraging the hard Drives to make
it run faster, buy all the neat Video Cards, network cards
and just about anything to make it run better ONLY:
To see some take street drugs which Cloud the mind, Slow
the Metabolism down, and sometimes ultimately kill the
user or land ( them ) in the hands of the tax payer who
foots the bill for the rest of their life in medical bills.
Freedom of Choice is a great thing, but home brew
( street ) drugs are a sure pathway ( and short trip )
to oblivion.
If one wishes to sell their Computer ( or anything else )
to buy street drugs, who am I to try and stop it. If the
majority wants it, and will support it, then it will happen.
I would hate to see a fellow Two-Way geru try to operate
his Astro-Saber or even a HT600 for that matter while under
the influance.
Its bad enough to watch these persons weave all
over the road while talking on a Cell-Phone. I would
hate to be on the road at the same time if the fellow
was under the influance trying to talk to his supplier.
Monty
Its Ironic that persons will spend 100's sometimes
1000's of dollars in Upgrading their Computer, Improving
its Memory, Scandisc, defraging the hard Drives to make
it run faster, buy all the neat Video Cards, network cards
and just about anything to make it run better ONLY:
To see some take street drugs which Cloud the mind, Slow
the Metabolism down, and sometimes ultimately kill the
user or land ( them ) in the hands of the tax payer who
foots the bill for the rest of their life in medical bills.
Freedom of Choice is a great thing, but home brew
( street ) drugs are a sure pathway ( and short trip )
to oblivion.
If one wishes to sell their Computer ( or anything else )
to buy street drugs, who am I to try and stop it. If the
majority wants it, and will support it, then it will happen.
I would hate to see a fellow Two-Way geru try to operate
his Astro-Saber or even a HT600 for that matter while under
the influance.
Its bad enough to watch these persons weave all
over the road while talking on a Cell-Phone. I would
hate to be on the road at the same time if the fellow
was under the influance trying to talk to his supplier.
Monty
-
Cat_Herder
- Posts: 28
- Joined: Wed Apr 24, 2002 12:58 pm
Security and misc...
Well, let me put my 2 cents worth in... I agree with the moderator...I too have seen some very very good technicians go down the tubes with the drugs and booze...it appears to be endemic within the electronic servicing industry...I attribute it to frustration of these technicians with management not willing (or unable...) to listen to these technicians that have to make systems work with equipment that is either poorly designed or poorly installed...By listening, I mean with their minds and NOT with just their ears...so, after a few years of frustration, they wander off to the "dark side" of alcohol and drug abuse...I know...I used to be a "sauce hound" and no, I am not proud of those 2 years I spent inside a bottle, I am proud of the fact that I pulled out of that bottle by myself after waking up to what I was becoming...<ahem> I digress... Anyway...for a secure system to work properly, the human element HAS to be taken into account for the weakness, and there are those out there that will take advantage OF that weakness... Encryption keys should be changed every day...ideally every 4 hours...I know..I know...that schedule would be really rough to maintain...but if you want to maintain operational security....Oh well...another 2 cents worth on a $500.00 laptop. 
"...No Matter where you go...There you are..."
I normally ignore posts of this ilk, but the thought that druggies are smart enough to break though digital communications is, in my neck of the world, laughable. I am reminded of a story.
This goes back to the days before ECPS, and when we still had IMTS. (I may be dating myself here.)
When the IMTS channels were idle, they sent out a very coherent tone that made a great (and convenient and free) beacon for testing antennas. We happened to be trying to demonstrate something to a PD official, using a couple of different antennas, a service monitor, and an IMTS beacon. All of a sudden, the idle tone dropped and a call was initiated. Before I could change to another IMTS freq, we heard a guy who had gone out to his car to call his lawyer, explaining that the local PDs were executing a search warrant for his premises as he spoke. "Are they going to find the drugs?" the lawyer asked. "No," the client responded, explaining exactly where they were hidden.
My guy picked up the phone and called his counterpart in the other city. They found the drugs, arrested the guy who made the call, and then arrested the lawyer on conspiracy charges.
This goes back to the days before ECPS, and when we still had IMTS. (I may be dating myself here.)
When the IMTS channels were idle, they sent out a very coherent tone that made a great (and convenient and free) beacon for testing antennas. We happened to be trying to demonstrate something to a PD official, using a couple of different antennas, a service monitor, and an IMTS beacon. All of a sudden, the idle tone dropped and a call was initiated. Before I could change to another IMTS freq, we heard a guy who had gone out to his car to call his lawyer, explaining that the local PDs were executing a search warrant for his premises as he spoke. "Are they going to find the drugs?" the lawyer asked. "No," the client responded, explaining exactly where they were hidden.
My guy picked up the phone and called his counterpart in the other city. They found the drugs, arrested the guy who made the call, and then arrested the lawyer on conspiracy charges.
-
ricciticcitembo
- Posts: 730
- Joined: Tue Feb 26, 2002 4:00 pm
that IS funny. Around here there are many "dealers" using "prepaid" cell phones that still use AMPS. not good for them. But they apperently don't know. And I won't even get into cordless.
They seem to think that if it's not "their" phone, then its OK to use.
Hahahaha
I heard snippits of 33 hours of taped phone conversations in court.
this included CDMA, AMPS,TDMA,land line. They do it all at the switch
though using ss7 so there is no need to "intercept" the wireless comms directly. As someone on this board said it is IMPOSSIBLE to monitor CDMA because of how it works, and I would have to agree with that. But ya just can't stop it at the switch!!!
Personally I still use my 8000 Brick phone and will continue to do so until the day comes where they cease and desist with the AMPS.
It is vastly superior to ANY digital phone including CDMA which is NOT an advancement in sound quality, just more efficient bandwidth utilization. Same thing with Astro. May Analog never Die.
They seem to think that if it's not "their" phone, then its OK to use.
Hahahaha
I heard snippits of 33 hours of taped phone conversations in court.
this included CDMA, AMPS,TDMA,land line. They do it all at the switch
though using ss7 so there is no need to "intercept" the wireless comms directly. As someone on this board said it is IMPOSSIBLE to monitor CDMA because of how it works, and I would have to agree with that. But ya just can't stop it at the switch!!!
Personally I still use my 8000 Brick phone and will continue to do so until the day comes where they cease and desist with the AMPS.
It is vastly superior to ANY digital phone including CDMA which is NOT an advancement in sound quality, just more efficient bandwidth utilization. Same thing with Astro. May Analog never Die.
Jamming the encrypted frequency
I wonder if anyone has experienced the criminal element jamming an encrypted police frequency during a "job"? Of course, the bad guy would have to know enough about the communication system to ensure they effectively neutralized it. But if you can't hear or decrypt comms... jam it... sort of like detente... "if I can't have it, you can't have it either"
Anyone seen this sort of thing happen?
RFDude.
Anyone seen this sort of thing happen?
RFDude.
What RFdude says makes the most sense. If you cannot listen, why not just jam it? At least the law would lose their communications during a bust. Druggies deciphering an encrypted signal is not laughable. With the millions of $$$ that these criminals have, they can go as far as employing a technician whom is familiar with the system is question. They could also pay a city/county/state radio technician to be their 'side' technincian. How much more convenient than having someone with the keys and also probably has a spare Astro laying around the shop. Easy money! If the druggies offer a city tech $5000 every week to provide a working receiver and keep their mouth shut, do you think they would have trouble finding someone to take the job? I sure as hell don't !! They could make a nice living with that.
With software/hardware that "available to law enforcement only", one can easily listen to most digitally encrypted signals. The best defense is constant change. Stay ahead of the crack heads. Every time you do a bust, change the keys. We even have a local PD that uses the "dot" frequencies when doing surveillance or a raid- it's the last place you'd expect to find them. They do their thing and five minutes later it's over and you won't hear them on the frequencies again...although not secure.
Don't let anyone fool you into thinking that Nextel is actually secure- it's far from it. A hobbyist won't listen in, but somebody with the proper skill and equipment will laugh at Nextel.
With software/hardware that "available to law enforcement only", one can easily listen to most digitally encrypted signals. The best defense is constant change. Stay ahead of the crack heads. Every time you do a bust, change the keys. We even have a local PD that uses the "dot" frequencies when doing surveillance or a raid- it's the last place you'd expect to find them. They do their thing and five minutes later it's over and you won't hear them on the frequencies again...although not secure.
Don't let anyone fool you into thinking that Nextel is actually secure- it's far from it. A hobbyist won't listen in, but somebody with the proper skill and equipment will laugh at Nextel.
A police licensee is not limited to "dot" channels for special ops. Under 47 C.F.R. sec. 90.20(f)(5), a police licensee may use any PP frequency for special ops with low power portables, without specific authorization and without coordination. In addition, in my neck of the woods, a number of FB2 and FB6s make tone pairs available on a special basis for local PDs running special ops that require more coverage than you can get with low-power portables.