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Private Investigations and Personal Security/Surveillance, Tracking and Bugs....and a hotel room.


QUESTION: Hey Jeffrey,

Got a doozy of a question for you, but first, a bit of context. I'm a screenwriter currently working on an assignment to adapt a best selling spy novel. Problem is, it's set in the Eighties and so to update it to modern day, I'm running into a few issues. Namely the advancement of current Surveillance tech verses what was available back in the day. And now to the question-

I have a scenario whereby a character is confined to a hotel room. He can walk around the hotel, but can't walk out. He will later find a bug in his room or a tracker on his person and attach it to the guard outside his room. The guard leaves and either divulges key info (bugged) or returns home (tracker).

The problem is, with not being able to leave the room, how can the main character monitor the bug? Is there any way he rewire/retool hotel room items (radio, phone, TV) to tune into the frequency of the bug.

Alternatively, if it's a tracker, is there anyway he can use those items to fashion a device to view the movements of the tracker?

If not, he does have access to the whole hotel. So could he fashion some device that could either tune into the frequency of the bug or monitor the whereabouts of the tracker? Maybe steals a guards radio/walkie-talkie or a businessman guest's laptop.

Of course, this brings up another problem. Namely, if the people who planted the bug realize that the bug has moved to another person, they'll be alerted to the deception (and they need to remain oblivious). Alternatively, if the tracker leaves the hotel on the guard, they'll think that the character has left the hotel (which will result in the death of his kidnapped daughter). So is there someway to jam a signal (for the bug) or hack a device to fool it into thinking the character hasn't moved (for the tracker)?

Any advice would be helpful. I feel I've written myself down a slight cul-de-sac. Hopefully you can guide me out.

Best regards


PS. I should state that the character is an expert in tech and software development so if bugs or trackers do use a public frequency, he could easily hack it with laptop wifi. If that were possible :)

PPS. I'm also concerned about issues like range with regards the bug. How far could the Guard leave until he's out of range of whatever the character fashions as a listening device?


I would be glad to help.  There are many types of "bugs" and systems from that time but they were still primitive when compared to today's systems (due to the mobile telephone innovations).  Due to the time period you chose laptop computers are still a thing of the future.  In the 1980's "bugs" primarily consisted of radio frequency transmitters.  What would be consistent with that historical era would be a small passive bug with no battery pack of its own, no wires, no power pack of any kind.  It could be very small perhaps the size of a pencil eraser that would energize when a beam of ultra-high frequency (UHF) radio signal was directed or "beamed' to it from a fixed location in a building or from a mobile platform like a van or similar vehicle.  Yes, the radio signal does penetrate through buildings and walls.  The UHF radio beam would energize the bug and then pick up and carry the sound or "conversation" back to the beam source through a process of the sound waves modulating the bug's diaphragm and causing a reflection of signal back to the source.  If the UHF beam is turned off the bug does not work.          

A UHF beam would be wide enough to cover a building so if the bug was transferred from one person to another it would still function.  The operating range of this type of system would be up to one mile or so.  The UHF radio transmitter/receiver would literally be the size of an old reel to reel set with headphones and the reels to record the conversations.  That is why the van scenario would be appropriate.  The bug can be used to track as well as the transmitting dish would have to be adjusted to "find" the mark.  In this scenario the bug cannot be hacked.  It can be planted on someone or something else.  

Alternatively your protagonist could tune to the frequency that the bug operates off of and build a similar transmitter to interfere with the villain's UHF beam.  The bug can be tested by placing it next to a working AM/FM radio and then tuning in on the right frequency with a handheld receiving device.  The sound waves from the radio would be heard over the receiver letting your protagonist know that he has located the frequency.  UHF operates in the range of 300 Megahertz to 3 Gigahertz. Obviously you still have choices and research to conduct.  I hope this helps.          

---------- FOLLOW-UP ----------

QUESTION: Awesome answer! And if, when it comes to rating, I could rate higher than 10 I would. There's a lot of great info here. Lot of stuff I need to research (purely from a general interest point of view).

But I realize my question wasn't clear. Although the original novel is based in the Eighties, I'm transposing it to the modern era.

So I'm looking for how bugs or trackers would be used today. And, whilst I like the idea of a bug, I realize microphones these days can be used from a building across the street. So I'm leaning more towards trackers.

What I'm thinking is, the main character secretly attaches the tracker planted on him onto the guard, then somehow detains him (since if the guard leaves the hotel, they will think main character left and kill his daughter) and has a set amount of time to hack the server the tracker is connected to so that he can make it look like the tracker never left the hotel. Can that be done? And can it only be hacked on a laptop? Or could he steal (pickpocket) a guest's PDA to do the hacking on?

Any help would be greatly appreciated. And my apologies for the initial era mix-up :)

Best regards



No problem.  The technology today is (obviously) very sophisticated compared to the 1980's so you have a lot of choices.  Cameras and "bugs" are very small.  For example, a fiber optic line can connect to a camera the size of a pinhole which is very hard to detect.  

As far as microphone or "bug technology use the previous example from the 1980's and replace radio UHF beam with laser technology.  The "bug" itself would be much smaller.  The principle of listening remains the same.

With regard to a tracking device I would recommend one that has microphone and Global Positioning System (hereafter GPS) tracking capabilities.  The smallest package would be about the size of a postage stamp.  It is energized by a rechargeable ion lithium battery that is powered for approximately one week.  It would transmit GPS data to the Internet for tracking purposes.  The microphone would transmit on virtually any frequency the builder wanted it to from the UHF bandwidth (which is what cellular telephones operate from).  In this instance your protagonist could be tracked via telephone or computer.        

A normal GPS receiver listens to a particular frequency for radio signals. Satellites then send time coded messages at that particular frequency. Each satellite has an atomic clock, and sends the current exact time as well. The GPS receiver figures out which satellites it can hear, and then starts gathering those messages. The messages include time, current satellite positions, and a few other bits of information. The message stream is slow, so as to save power, and also because all of the satellites transmit on the same frequency and they're easier to pick out if they go slow. Because of this, and the amount of information needed to operate well, it can take from 30-60 seconds to get a location on a regular GPS system.

When it knows the position and time code of at least 3 satellites, a GPS receiver can assume it's on the earth's surface and get a good reading. 4 satellites are needed if you aren't on the ground and you want altitude as well.  

So to recap, generally speaking, a GPS tracking unit is a device that uses the Global Positioning System (GPS) to determine the precise location of a vehicle, person, or other asset to which it is attached and to record the position of the asset at regular intervals. The recorded location data can be stored within the tracking unit, or it may be transmitted to a central location data base, or internet-connected computer, using a cellular (GPRS or SMS), radio, or satellite modem embedded in the unit. This allows the asset's (person, thing, etc.) location to be displayed against a map backdrop either in real-time or when analyzing the tracking data later, using GPS tracking software.

Your protagonist can "hack" into the signal transmitted from the unit and block it or interfere with it.  My suggestion would be to interfere with the signal by delaying it for minutes at a time.  You will have to use creative license here with regard to software programming but you should have no problem there.  I hope this information is helpful.  

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Jeffrey Hauck


I would welcome the opportunity to answer questions about the business operations, duties, and ethics of the modern professional private detective/private investigator.


Criminologist. Professor of Criminal Justice. Licensed Private Detective with expansive clientele base encompassing hundreds of cases. Donates resources and time to the Children's Rescue Network in Orlando, FL.

Associate of Science; Bachelor of Arts; Master of Science, Doctor of Jurisprudence Degree.

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