TSCM stands for Technical Surveillance Countermeasures, a process known also known as electronic counter-surveillance, colloquially referred to as a “bug sweep”. Sweeping for bugs is one of the most technically advanced services that private investigators can offer, because it requires an array of expensive equipment along with trained experts who are aware of the proper techniques to use the equipment correctly.

How is Bug Sweeping Performed?

While they may look simple in movies and on TV, bug sweeps are actually very difficult to perform. A trained expert must use a practiced methodology adapted to defeat the attacker’s technology and the attacker themselves, who may have taken steps to avoid detection.

Most common surveillance devices emit some sort of radio frequency to transmit data, so a TSCM expert will start by attempting to detect a radio signal. At its most basic level, using bug sweeping equipment is like tuning a radio. The bug is transmitting a radio signal containing the surveillance information being collected, be it video, audio or another kind of data. The operator must simply tune their bug sweeping device the the right frequency to catch the radio signal, just like tuning your car radio to catch the news.

This will only defeat the most basic of bugs however, because attackers may avoid detection using techniques like burst transmission or spread spectrum transmission. A burst transmission device collects information over a period of time, then sends it out all at once in a short burst, so the person sweeping for bugs won’t detect a signal unless they’re listening at exactly the right time. Spread spectrum transmission on the other hand, spreads the signal over a larger spectrum of radio frequency than a normal radio transmission, so that the signal is too quiet to be picked up unless the Technical Surveillance Countermeasures equipment is specially attuned to catch the correct spread spectrum transmission.

Some surveillance equipment on the other hand doesn’t produce radio waves. These surveillance devices simply record information for later when the attacker has the opportunity to come back and collect the bug. To detect these devices the person sweeping for bugs can use a device that detects the magnetic fields given off by all computerized technology, or use thermal cameras to detect a heat signature. However, this may be impossible if the bug is in an office of another place filled with electronic devices because they magnetic fields and heat produced by other electronics will conceal the bug. In this case the bug often must be found through old fashioned physical searching.

Types Of Technical Surveillance Countermeasures Equipment

These are a few of the most common kinds of bug sweep equipment:

• Multimeter – A basic scientific tool that can detect electrical currents.
• Time-domain reflectometer (TDR) – Used to test the integrity of phone lines.
• Frequency scanner with a range of antennas and filters – Used to scan for radio frequencies.
• Spectrum analyzer and vector signal analyzer – Used for more advanced analysis of threatening and non threatening radio signals.
• Nonlinear junction detector – Used to detect other hidden eavesdropping devices.
• Portable x-ray machine – Used to look for bugs inside of walls and objects.
• Computer security devices – Used to detect computer-related threats.
• Flashlight and traditional tools – These are used when all the high tech gadgets fail and you need to go in manually.

Alternatively the tools are used if a bug is found but needs to be manually extracted.

As you can see, bug sweeping is a complicated process that requires not only huge number of gadgets, but also knowledge of how attackers operate, such as where they place their bugs and how they use them. So while it may have looked easy on that episode of Miami Vice, in reality, it’s best left to the professionals.