Doppler Radar Used By Police To Determine Home Occupancy

schwit1 sends an article by Orin Kerr about a court case where a judge has had to weigh Fourth Amendment protections against law enforcement's ability to use a Doppler radar device to tell whether people are present within a home. Kerr writes: If the government has the burden of proving reasonable suspicion, should the court treat the absence of information in the record on this point as not changing its otherwise-reached view that there is reasonable suspicion (as it does), or should that be treated as a potentially serious deficiency in getting to reasonable suspicion that the government has to overcome? I’m not sure of the answer. We don’t normally encounter this question because we normally understand the uses and limits of investigatory tools. If the officer looked through the window and didn’t see any other people, for example, we could intuitively factor that into the reasonable suspicion inquiry without having to think about burdens of proof. I’m less sure what we’re supposed to do when the government use a suspicion-testing technological device with unknown capabilities." The judge in the court case wrote, "New technologies bring with them not only new opportunities for law enforcement to catch criminals but also new risks for abuse and new ways to invade constitutional rights (PDF). ... Unlawful searches can give rise not only to civil claims but may require the suppression of evidence in criminal proceedings. We have little doubt that the radar device deployed here will soon generate many questions for this court and others along both of these axes."

Comments

Other Tech Already Infiltrating Homes' Privacy

[rmdingler]

This internet of things craze leads me to believe law enforcement will be able to determine not just if, but who is home from a desktop on the other side of the World.

Nest-type thermostats, entertainment streaming, alarm systems, and the beat (down) that is voluntary surrender of privacy goes on.

Re:Other Tech Already Infiltrating Homes' Privacy

[Bob9113]

I like your IoT angle, so I'm going to hang my comment here (I'll tie it in to your comment at the end).

If the officer looked through the window and didn't see any other people, for example, we could intuitively factor that into the reasonable suspicion inquiry without having to think about burdens of proof.

I think it is easy to make the call with looking in the window because everyone knows how to pull their curtains. Pulling your curtains carries force of law telling government representatives, "I don't want you to look at me right now, unless you have a warrant." That is the essence of the right to be secure in ones home; that you have the authority to say that the government is not permitted to observe your home without a warrant, regardless of technological capability.

Does the same apply to Doppler radar, or IoT records? Do people have an easy and commonly known way to say, "I do not want the government to look at electromagnetic radiation or business records that indicate what is happening in my home"? If people do not have a commonly known way to indicate consent or lack thereof to be observed, which carries the same force of law as curtains, then a warrant is required to uphold the intent of the 4th.

And to address a following point that may get raised; electric meters are sometimes used as evidence of what is happening inside a house. I think that also violates the intent of the 4th.

But what we really need is not to understand the intent of the 4th. What we need is for the public to consider that the marginal cost of law enforcement may have exceeded the marginal cost of crime. That is to say; we may have too little crime relative to the cost (including the cost to liberty and dignity) of law enforcement.

Re:That's an attack!

[Charliemopps]

Radar is non ionizing. It could cook people, though, if it has enough power.

Actually, yes it can lead to cancer: http://www.iarc.fr/en/media-ce...

When you get your Armature radio license they hand you a sheet with warnings and exposure levels. Non-ionizing isn't nearly as bad as Ionizing radiation where even very low levels are dangerous. You need much higher energy levels of non-ionizing before it becomes dangerous. The 1 watt you find in most wifi devices is far far bellow what would be considered dangerous. I have a 70 watt 2 meter radio and even that's safe.

A wall penetrating Doppler radar device though? I would be concerned if that were pointed at me for anything more than a split second. It was deffinately not designed to be pointed at sleeping children. You'd really need to know exactly how it works though. The danger with non-ionizing radiation is not strait forward. It's not like you can just say "1hr of exposure to 1000watts is where it becomes dangerous!" It changes depending on the Frequency, duration, power and distance from the antenna. So it's really hard to say. I would think the FCC might be interested in talking to this police station.