How Police Listen to You Part 4: Range-R, the Device That Helps Cops See Through Walls

Thibault Serlet





Police can now see through walls.

The fact such technology exists should hardly come as a surprise considering America’s seemingly never-ending race to become a dystopian police state. Using a small portable microwave radar known as the RANGE-R, police can identify the location of people and objects behind walls.

How is RANGE-R Used?

In order to determine the locations of the occupants of a building, all an officer has to do is hold the RANGE-R against the wall. The distances of all moving objects within a 160° range is then revealed to the user via the device’s LED screen. This allows police to tell if anyone is hiding inside a building, perhaps with the intention of ambushing officers.

How Does RANGE-R Work?

According to its manufacturer, the RANGE-R weights less than two pounds and is powered by 4 standard AA batteries. The devices cost roughly $2000 each.

The RANGE-R is a standard Doppler Radar modified for indoor use, similar to the ones used by traffic enforcement in speed traps. When the RANGE-R is pressed against a wall, it emits a series of brief microwave pulses. Whenever the pulses hit an object, a small fraction of the microwave is bounced back towards the device. The device then calculates the distance of the objects by measuring the amount of time it takes for the signal being bounced back to return to the radar.

Microwave has a low enough frequency that it can easily penetrate through thick concrete walls, but will not penetrate metal. The manufacturers believe that RANGE-R will not be significantly impeded by metal-embedded materials such as rebar.

In order to detect motion, the RANGE-R sends multiple pulses into the room being targeted. Static objects will always have the same bounce back time, while moving objects will have slightly different frequency over time. This allows the RANGE-R to detect motion with precision, and thus distinguish people from stationary objects. The RANGE-R’s motion detection is sensitive enough to detect an individual breathing as far as 50 feet behind a brick wall.

Objects are finally classified into two categories: movers and breathers. Stationary objects are discarded. Breathers are objects which are only slightly moving, while movers are moving significantly.

History of Use

RANGE-Rs have been in use since 2012. Although the extent of RANGE-R technology’s use is unknown, Justice Department Spokesman Patrick Rodenbush said that Federal Marshals routinely use RANGE-R to execute arrest warrants. The Federal Marshals are believed to have spent as much as $180,000 on RANGE-Rs.

Use of RANGE-Rs was an open secret until the December 30 2014 Federal Court ruling United States of America vs Steven J. Denson. After Denson, convicted for armed robbery, missed several meetings with his probation officer, a SWAT team raided his residence. The SWAT officers determined Denson was inside his house by using RANGE-R, and proceeded to carry out their arrest warrant. Inside the house, they found a stash of illegal firearms. After the raid, Denson sued in the 10th Circuit Court of Appeals that the officers had violated his Fourth Amendment right by deploying the handheld doppler radars. The court ruled against Denson’s favor.

According to USA Today’s groundbreaking report on the topic, at least 50 agencies including the FBI are confirmed to posses RANGE-R or similar technology.

The coalition forces in Iraq and Afghanistan have been using similar technology when conducting raids for years.

The Dangers It Poses to American Freedoms

There are currently no Federal rules or guidelines restricting the use of RANGE-R and similar technology. Privacy advocates are concerned that the lack of regulation means law enforcement will be tempted to use the technology with impunity.

The ACLU argues that the use of similar technologies erodes the Fourth Amendment. Use of RANGE-R supports the hypothesis that all technological evils are first used for good.

Currently the manufacturer boasts that new iterations of the technology are far more sophisticated and are capable of generating real time 3D models of the inside of a building.

As the technology progresses, the possibilities become increasingly alarming. In the near future, a police department will be able to use large-scale doppler scanning to determine the positions off all the occupants within an entire neighborhood and analyze them using BRS technology. Once BRS is combined with persistent interior doppler scanning, it will effectively as if the state had cameras inside every room of every house.

Arguing for the continued expansion of radars which scan the interiors of buildings eventually becomes equivalent to arguing there should be a surveillance camera and microphone inside every house. At least cameras can be covered, and microphones detected. This isn’t the case for BRS.

Possible Countermeasures

The manufacturers admit that RANGE-R isn’t capable of penetrating metal walls. However, coating walls with metal or metal fragments isn’t an option for most people.

Slightly easier than protecting all possible attack surfaces might be the use of chaff. During WW2, pilots would drop small pieces of metal from their airplanes to jam enemy radar. Chaff is widely used as a detection countermeasure by armies around the world, although it has been made mostly irrelevant since the invention of space-time adaptive processing. To make chaff, aluminum foil can be cut into small strips and attached to the surface to be protected. Do not use tin foil!

Both countermeasures described above are perfectly legal in the United States. The one described in this paragraph is legal in most countries, but illegal in America. Because RANGE-R and similar doppler radars use microwaves, frequency jamming could be used. The easiest way to do this is by turning on 3-4 kitchen microwaves at the same time. A more technically advanced solution would be to use a device such as a modified IMSI-catcher.

Stay safe, and whatever you do, don’t break the law.

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