“Police radar can ‘see’ inside homes,” trumpeted a recent USA Today headline. The handheld devices aren’t like Superman’s X-ray vision that let him see through clothes and barriers. Looking like a fancy stud-finder, the device uses radio waves and the display shows whether it detects motion as slight as human breathing on the other side of a wall and, if so, how far away it is.

But commenters who focus on how the media is overhyping the technology miss two pressing points:

1. The media is reporting that law enforcement agencies have kept their use of this technology “secret.”

2. The technology has significant Fourth Amendment ramifications.

Let’s look at both of these in turn.

Private vs. Secret

There’s a difference between secret and private. Private is deciding to withhold something from public view for any number of acceptable reasons. Examples are changing clothes, an early pregnancy, a new relationship. Secret is deciding to keep something hidden out of fear or shame.

USA Today characterized police use of the motion detection technology as “secret.” To the media, that could mean police didn’t issue a press release.

According to the article, federal officials discussed how the device could be critical for keeping officers safe if they need to storm buildings or rescue hostages. The Marshals Service’s purchases of the devices were documented in federal contract records.

The manufacturer of a model called Range-R — apparently not bound by any non-disclosure agreement — provided an estimate of the number of law enforcement agencies that had purchased the devices and the number sold. And a Deputy U.S. Marshal testified in court about using the Range-R.

Neither Private Nor Secret Anymore

The case in which the Deputy Marshal testified resulted in a federal appeals court opinion that was published on December 30, 2014. That appears to have sparked the media’s attention. Rest assured, the proverbial cat is out of the bag.

The Marshals had an arrest warrant for Steven Denson for parole violations on an armed robbery conviction. At issue on appeal was the lawfulness of their entry into a home to make the arrest and their subsequent search therein without a search warrant. That search discovered guns and resulted in additional charges.

The Deputy Marshal testified he used a Range-R to detect someone was inside the house. The federal court upheld the entry, search and seizure of the guns on facts independent of the Range-R information so it didn’t resolve the Fourth Amendment questions raised by the use of such a device. But the court had strong words that prosecutors and police would be well-advised to heed:

“It’s obvious to us and everyone else in this case that the government’s warrantless use of such a powerful tool to search inside homes poses grave Fourth Amendment questions. 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. [Citation omitted.] 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.”

Where are the Prosecutors?

As a former state and federal prosecutor, I find it hard to believe that 50 law enforcement agencies — as reported by USA Today — are using Ranger-R’s and none of them are consulting prosecutors. Not impossible, just improbable.

Prosecutorial power is huge. It demands the highest responsibility and accountability.

The federal court in Kansas was right when it said a tool that enables police to detect people’s movements in their homes raises grave Fourth Amendment questions. That should be clear to any prosecutor.

Looking to GPS Rulings

Cops and prosecutors hurt their professions when they over-reach and under-reveal. I don’t know why the media is just taking aim at the police and not questioning prosecutors’ involvement with warrantless use of this technology.

Both professions undermine their credibility — with courts and the public — when they overreach. Federal officials say Ranger-Rs can help keep officers safe if they need to storm buildings or rescue hostages. I agree. Those situations present exigent circumstances. The facts of the Denson case didn’t.

It’s worth noting that the Deputy Marshal’s report made no mention of the device but said only that officers “developed reasonable suspicion that Denson was in the residence.”

After the Supreme Court accepted U.S. v. Jones, but before it’s 2012 decision that police could not install a GPS device on a vehicle without a warrant, a federal agent shared with me his concern about a suggestion in his office that agents continue to use GPS devices on suspects’ vehicles without a warrant. When I questioned the wisdom of that given what might happen to such cases if the Court ruled a warrant was required, he said it had also been suggested that agents not mention the use of the devices in their reports.

I don’t know whether the suggestion came from a prosecutor, a supervisor, both, or neither. If from a prosecutor or law enforcement officer, I consider it dishonorable. There’s a Yiddish proverb, “A half-truth is a whole lie.”

Prosecutors and police deal with important matters. We cannot be careless — or worse — and expect to be trusted.

I understand the reasons behind not providing press releases containing details about newly developed law enforcement technology. That doesn’t justify keeping such information private or secret from court oversight or review.

Before using radar vision, police and prosecutors should consider the same four steps recommended for tracking cell phones.