Episode 59: Crimes and Myth-Demeanors 2

Air Date: August 23, 2006

The optical fingerprint reader the Mythbusters installed can be fooled by a copy of an approved fingerprint etched in latex.


Licking the latex sample (to simulate sweat) was enough to fool the scanner.

(This was the only method that also fooled the Mythbusters’ computer-based biometric sensor.)

The optical fingerprint reader the Mythbusters installed can be fooled by a ballistics gel copy of an approved fingerprint.


Licking the gel sample (to simulate sweat) was enough to fool the scanner.

The optical fingerprint reader the Mythbusters installed can be fooled by a paper copy of an approved fingerprint.


Licking the paper sample (to simulate sweat) was enough to fool the scanner.

A heat detector can be fooled by cooling the body down using a CO2 fire extinguisher.


Not only was the sensor not fooled, using a fire extinguisher on a person is dangerous.

A heat detector can be fooled by a neoprene diving suit.


The neoprene suit did insulate body heat from its surroundings, until the suit itself warmed up.

A heat detector can be fooled by being covered in mud.


Like the neoprene suit, it only worked until the mud warmed up from body heat. Also, Tory left behind mud tracks while attempting this.

A heat detector can be fooled by heating the room to body temperature.


Heating the room from the ceiling immediately set off the sensor, while heating the room from the ground did not. However, the sensor was still sensitive enough to detect the difference between human body temperature and the ambient temperature.

A heat detector can be fooled by wearing a highly insulated fire proximity suit.


The suit blocked the body heat, preventing the sensor from seeing the wearer. However a small breach in the suit triggered the sensor when pointed towards it.

A heat detector can be fooled by placing glass between the intruder and the sensor.


Glass blocks out infrared light (i.e. heat).

An ultrasonic motion detector can be fooled by wearing thick-padded clothing.


The sensor was still able to pick up Kari’s movement.

An ultrasonic motion detector can be fooled by holding a bedsheet in front of you.


The bedsheet absorbed enough of the ultrasonic waves to mitigate any return signals.

An ultrasonic motion detector can be fooled by moving extremely slowly.


Although it took Kari 20 minutes to cross a relatively short hallway, she moved slow enough to stay below the detector’s sampling threshold.

A thief can drill into a safe with a thermal lance, fill the safe with water, and detonate an explosive inside without damaging the items inside or prematurely activating the glass relocker.


Drilling into a safe using thermal rods takes far longer than the myth states. Also, the heat from the thermal rods completely destroyed the items inside. Secondly, the safe was not watertight and had to be sealed from the inside in order to completely fill it with water. Finally, even though the explosion successfully dislodged the safe door, none of the items inside remained intact. It was deemed plausible for historical precedent and police reports, even though the MythBusters themselves could not replicate any of the conditions.


  1. Jawa says:

    I would think that moving extremely slowly would only be plausible, because if you need to be fast, you don’t have 20 minutes to go across a hallway.

    • ThatGuy says:

      What are you even talking about? The time it takes to complete a task has no effect on whether or not it can be done. The question is “can this be done” the answer is “yes, in this way”.

  2. Brad Velander says:

    For the alarm system defeat attempts you did not trying two variations I learned while working in the security industry for a decade.
    With most Ultrasonic motion detectors there is a walking pace that can be used successfully to defeat them. We confirmed this in our employers showroom many times. The pace is slightly faster than a medium walking pace but the speed must be controlled very tightly and directed straight on toward the sensor. It is virtually impossible to do reliably.
    For infrared motion detectors, extreme low temperature arctic rated thermal wear including full face bellaclavas, gloves and socks can be used. Although the average thief may die of heat frustration prior to successfully getting in and out of a building.

  3. Gabor Temesi says:

    He is respected Mythbusters!
    It would be written down for me who is his manufacturer it for imprint lock?
    Thank you.

  4. Melissa says:

    For the “An ultrasonic motion detector can be fooled by holding a bedsheet in front of you” myth might have omly worked because it was a white sheet used in a white room.

    • Dan says:

      Sound waves don’t see colors.

      • Tim says:

        hehehe… nice catch :D

  5. JourneymanWizard says:

    Since an ultrasonic detector uses high-frequency sound waves, I find it highly doubtful room and sheet color would have an effect on the result.

  6. xyphoidmax says:

    Who cares? Grant wasn’t wearing clothes! WOOO!

  7. appleking says:

    I dont know wether this is the one i am thinking of but if you etch a circle in glass and try to take it out with a suction cup it should probably be smaller than the area that you are trying to extract.

  8. R.J. says:

    Umm, yeah Melissa, that was pretty dumb. Actually it was really dumb considering the defintion of ultrasonic. The myth had absolutely nothing to do with visuals; it is entirely based on sound waves. I really hope what you wrote was a joke.

  9. MIke says:

    the waterfiled safe exploding… I am journeyman locksmith… wath was the make of the safe and class rating… 1 2 3 or 4
    (tl15 or tl30) fire rated or composite..
    I am interested in maybe revisiting this myth by possiblly donating a class 4 jewlery safe!!

    and I totally dig the show… !!! keep up the safe and awesome work guys and gals!!

    PLS Security

  10. andres lopez says:

    hola minombres es andres lopez y me gusta mucho su programa … y puesto que no encontre otra forma para comunicarme con ustedes lo hago por este medio espero lo vean y lo leean … hace un tiempo me llego un correo donde decia que un miƱo avia muerto corque seavia tomoado una cocacola y minutos mas tarde se comio una menta y minutos mastarde murio por que el estomago le exploto porfavor me gustaria saber que tancierto es eso pues

  11. a mac says:

    endres lopez … no es posible que te mueras por eso.. este cuento tiene desde los 1970s con un dulce llamado “pop rocks” lo muerdes y truena en tu boca.. el cuento empeso que alguin murio por tomar coca-cola con el dulce… es un cuento solamente.

  12. caleb says:

    I really liked this one. They also had a glass re-locker in the new version of the Italian job. There’s going to be a sequel to the new version of the Italian job called the Brazilian job.

  13. Emmett says:

    A heat detector can be fooled by a neoprene diving suit.

    They need to keep exterior of neoprene suite down.

    -> Cover exterior of neoprene with cooled jell packs like the ones used to apply cold to injuries.

  14. John says:

    but that’s not really using the suit is it?

  15. Jim says:

    I liked all the heat detector ones.

  16. Neil says:

    Was the Heat Detector being fooled by Mud come from the movie Predator when Arnold is covered in mud and Predator doesn’t see him? I am wondering if a Lead Vest will fool the Heat Detector – Since Lead Vests are used to block X-Rays.

  17. Bonnie says:

    The heat detector emits infrared. Different from x-rays.

  18. Carter says:

    Also, a vest wouldn’t cover the face or hands, the strongest sources of infrared from a clothed human body.

  19. Andrew says:

    It would be interesting if the sheet also could fool the infrared detector. The sheet being cool, and not in contact with the body should stay cool…

    • Magnus says:

      Yes a towel or basically anything you can put between yourself and the sensor works fine, tested it on my alarm.

  20. Jayvee says:

    besides using towel or something else do you think that paper can do the same?

  21. joey D says:

    I wanna know what kind of jacket Adam had on in this episode that green one with all the patches?

  22. Sam says:

    In the movie called the Saint (1997) Val Kilmer wears what looks like a black military flight suit (Apollo/Skylab A7L suit) to match his body temperature to the surroundings to fool the security system.

    I also wonder if sun screen with UV protection would fool an infrared camera?

  23. Sam says:

    I find it interesting that glass can fool an infrared camera while in most homes windows tend to be a source of heat loss. This is because heat can be transfered in three ways radiation, conduction, and convection.

    • ChuckH says:

      Windows tend to be a source of heat loss bc they are poorly insulated. Glass allows light thru which warms up the house but does not actually allow the heat itself to escape back through the glass. Hints the purpose in the design of a greenhouse.

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