Radley Balko is getting a lot of attention for his provocative post “Federal judge: Drinking tea, shopping at a gardening store is probable cause for a SWAT raid on your home.” It sounds crazy, right? Why would a federal judge think that drinking tea and shopping at a gardening store amounts to probable cause?

Fortunately, there was no such ruling.

Yes, there was a legal decision, but it had nothing to do with visiting gardening stores or the culpability of drinking tea. Instead, the issue in the case was when the police can rely on positive field tests for THC, the active ingredient in marijuana. The judge ruled that officers cannot be held personally liable for searching a home with a warrant based on two positive field tests for marijuana, a week apart, from plant materials found in the suspect’s discarded trash, at least when the officers did not know about the risks that the field tests results were false positives.

Here’s what happened. As the affidavit in support of the warrant explains, officers placed a suspect under surveillance after the suspect made a purchase at a particular hydroponics store that officers believed was largely used by those growing marijuana. A few months later, officers searched the trash from the suspect’s house and found some plant material that in the lead investigator’s view “appeared to be wet marijuana plant material (leaves and stems).” Based on the officer’s “law enforcement training and experience,” it appeared as though it had been saturated through a liquid to extract THC, the active ingredient in marijuana. The officer field tested the plant material, and it tested positive for THC.

The next week, the officers searched the trash again. Again, the officers found plant material that tested positive for THC. The affidavit describes the plant material found the second time as “1/4 cup saturated marijuana plant material (leaves and stems)” that was “consistent” with that found the previous time.

The lead agent drafted a warrant to search the house based on this information. Before submitting the warrant to the judge, the agent asked an assistant district attorney to review the warrant. The prosecutor agreed that the warrant was proper. The lead agent then submitted the warrant application to a judge, who signed the warrant to search the house.

But it turned out to all be a mistake. The “plant material” was just loose-leaf tea. The field test results were false positives. The visit to the hydroponics store was to buy supplies for an indoor hydroponic vegetable garden.

With the benefit of hindsight, all the suspect did was drink tea and buy supplies to grow vegetables. That explains Balko’s headline.

The homeowners sued the officers, among others, claiming a violation of their Fourth Amendment rights. Their complaint raises a lot of issues. But let’s focus on the one that Balko’s headline addresses, the entering of the house. Should the officers be liable for entering the house with a warrant not based on probable cause?

Importantly, the constitutional question is whether the agents had probable cause to believe there was marijuana in the house before the search occured, not whether they turned out to be correct with the benefit of hindsight. And because this a case seeking money damages from the officers who participated in the search, the case involves the qualified immunity doctrine. That means that the question is more deferential: Could a reasonable officer believe he had probable cause?

In his opinion, Judge Lungstrum concludes that having two positive field tests for THC, at different times, is enough evidence to avoid personal liability for the officers. Even if there was no other evidence at all, those two positive test results were enough: “The fact that Deputy Burns’ affidavit states that the material found in the Hartes’ trash on two consecutive weeks field-tested positive for the presence of THC,” the judge writes, “is a hurdle that is all but impossible for plaintiffs to overcome.”

In his blog post, Balko argues that the problem with relying on field test results is that the field tests used in this case were very unreliable.

That raises an important question: Just how accurate are drug field tests, and how much should the police be allowed to rely on them to get warrants? Maybe courts should scrutinize field test results more, much like some lower courts did for dog sniffs before the Supreme Court largely put the kibosh on that scrutiny in Florida v. Harris.

Those are really interesting issues. But based on my reading of the plaintiffs’ memorandum opposing the defendant’s motion for summary judgment, the plaintiffs didn’t squarely ask the court to get into them. The most relevant part seems to be on page 62, where the plaintiffs argue that the problem is that the agents must have known that their affidavit was misleading. The problem with the warrant isn’t that the judge signed it, they argue, but that the authors knowingly left out the really important information that would have demonstrated to the judge that probable cause was lacking:

Had the search warrant affidavit not been littered with misleading statements and material omissions – including the fact that the field test has a very high false-positive rate and yields false positives for common kitchen herbs, spices, and caffeine – the affidavit would have been insufficient to establish probable cause. These misrepresentations and omissions show reckless disregard. An officer does not act reasonably when he knows the information he is acting on is false. See Wilkins v. DeReyes, 528 F.3d 790, 805 (10th Cir. 1990)

The plaintiffs are relying on Franks v. Delaware, a Supreme Court case that arose in the context of motions to suppress. In Franks, the Court held that a criminal defendant can attack a facially valid warrant based on knowingly or recklessly false statements contained in the affidavit. If a defendant can establish that the warrant was based on knowingly or recklessly false statements that created the probable cause, then those statements are subtracted from the considerations of probable cause when reviewing if the warrant was valid. Franks has been extended by lower courts to material omissions; the idea is that leaving something important out is as big a problem as adding in something false.

The plaintiffs in this case accepted that Franks also applies to civil suits. They also accepted that they have the burden of showing that the officers knowingly or recklessly omitted material facts that could have shown why there was no probable cause. With the case so framed, Judge Lungstrum ruled that the legal standard wasn’t satisfied on the facts:

While the court does not doubt that a judge would have wanted to know that the field test kits that Deputy Burns and Deputy Blake were using tended to yield false positive results “at a high rate,” there is simply no evidence that Deputy Burns or Deputy Blake had any knowledge of that information.

In fact, as plaintiffs point out in their submissions, Deputy Burns testified that, at the time he tested the plant material he discovered in plaintiffs’ trash, he had no knowledge that anything other than marijuana could test positive on a marijuana field test kit and that he was “not aware” of the possible occurrence of false positive test results. Deputy Blake’s testimony on those issues is substantially the same. Moreover, Sheriff Denning testified that, since he came to the Johnson County Sheriff’s Office in 1978, the Office has conducted “thousands” of field tests and the only false positive results of which he is aware are the results at issue in this case.

There is no basis to conclude, then, that Deputy Burns or Deputy Blake should have known that the field test kits they were using tended to yield false positive results. And even assuming that Deputy Burns or Deputy Blake should have known, as plaintiffs suggest, that a false positive is at least a theoretical possibility, plaintiffs have not shown that Deputy Burns recklessly omitted that information from the affidavit, where he clearly stated on two occasions that the rest result was “presumptive” but “not conclusive” for the presence of marijuana and neither Deputy Burns nor Deputy Blake had any particularized knowledge concerning the likelihood of obtaining a false positive under the circumstances presented. See Molina ex rel. Molina, 325 F.3d at 971 (rejecting argument that officer should have discussed in the search warrant affidavit the fact that field tests were unreliable; plaintiffs presented no evidence that officer had reason to know that field tests were unreliable when he applied for the warrant).

For all of these reasons, then, plaintiffs cannot establish that Deputy Burns recklessly failed to disclose that the field test kit utilized by Deputy Burns and Deputy Blake tended to yield false positive results at a high rate. See United States v. Comer, 565 Fed. Appx. 729, 731-32 (10th Cir. 2014) (record did not support finding that investigator recklessly omitted informant’s criminal history from warrant affidavit where there was no evidence that investigator had knowledge of informant’s criminal history).

There are some interesting civil procedure issues here about who should have the burden of proof and how much evidence should be satisfied at this stage of the litigation. Perhaps they will be addressed more fully in the expected appeal.

But whatever the answer to those questions should be, note that the judge’s ruling doesn’t have anything to do with whether visiting a gardening store or drinking tea amounts to probable cause. It also doesn’t get into the false positive rates of field tests, as the legal issue as accepted by the plaintiffs didn’t require the court to get there. Instead, this part of the case was just about whether the officers knew enough about the false positive rates of field tests to challenge the warrant based on the absence of that information in the affidavit.

Maybe it’s right, maybe it’s wrong. But it’s a pretty technical Fourth Amendment issue that seems pretty far removed from what you would imagine from reading Balko’s post — and especially his headline.

UPDATE: Some readers have objected that this post doesn’t condemn the officers for their search. That is, the post focuses on what the judge did, not whether the officers behaved well or poorly. Just to be clear, then, this search should be an enormous embarrassment for the officers. The lead officer should probably be reassigned to a different job if he hasn’t been already. The officers should have investigated the case much more carefully, and it’s particularly bad that the officer looked at tea and thought it was marijuana. What kind of experienced officer can’t tell the difference?

With that said, I wrote this post because I think there is value in being accurate about about what the judge actually ruled and why. Balko’s post triggered a lot of anger. And from what I saw online, much of that anger was directed at the judge for issuing such a ridiculous decision. Given that, I thought it was worth clearing up what the judge actually ruled on and why. Maybe it’s too technical for some. A long post on the law isn’t for everyone. But I thought it worth explaining for those trying to figure out not just whether something went wrong, but who is responsible for it.