How is it possible that a motorist pulled over for a rolling stop could end up being forcibly subjected to two X-rays, two digital probes of his anus, three enemas, and a colonoscopy, none of which discovered the slightest trace of the drugs that police claim to have thought he was hiding inside himself? That is the question raised by a federal lawsuit that recently received wide attention after it was highlighted by KOB, the NBC affiliate in Albuquerque.

The answer says a lot about the outrageous indignities we have come to tolerate in the name of the war on drugs, which has undermined our civil liberties to the point that what happened to David Eckert after he was stopped in Deming, New Mexico, seemed perfectly justified to the cops who detained him, the prosecutor who approved their application for a search warrant, the judge who granted it, and the doctors who helped execute it. Even in retrospect, Deming Police Chief Brandon Gigante insists that "we follow the law in every aspect." The really horrifying thing about Eckert's ordeal is that the courts might agree with Gigante.

Officer Robert Chavez pulled over Eckert's Dodge pickup truck on January 2 in the parking lot of the Walmart in Deming after a detective told Chavez he had seen the vehicle pass a stop sign without coming to a complete stop. Chavez later reported that Eckert seemed nervous: He avoided the officer's gaze, and his hand shook as he gave Chavez his driver's license, vehicle registration, and proof of insurance. "While Mr. Eckert was standing outside of the vehicle," Chavez added, "I did notice his posture to be erect and he kept his legs together."

Chavez claims Eckert gave him permission to search the pickup truck, which Eckert denies. In any case, Eckert's permission was not necessary for what came next: a "free air sniff" of the vehicle's exterior by LEO, a drug-detecting dog overseen by Hidalgo County Sheriff's Deputy Patrick Green. The Supreme Court has said such an olfactory inspection does not count as a "search" under the Fourth Amendment and can be performed at will during routine traffic stops.

According to Green's report, LEO "alerted" to the driver's seat of the pickup truck, which means he indicated the presence of "an unknown narcotic odor" with a signal he had been trained to give, such as sitting, barking, or scratching. Did that really happen? Since there appears to be no video of the inspection, we have no way of knowing for sure, just the word of a cop who may have been eager to help his colleagues justify a search they seemed determined to perform.

Assuming LEO did alert, was it because he smelled contraband, or was he reacting to some other odor or to Green's cues? Again, we don't know, and in practice it does not really matter. In Florida v. Harris, decided last February, the Supreme Court said a police dog's alert provides probable cause for a search unless the animal is shown to be unreliable.

Eckert argues that LEO is unreliable, since he was not recertified when he should have been and has alerted at least three times to vehicles in which no drugs were found, including the January 2 stop and a 2012 stop in which Eckert was pulled over for a cracked windshield. Judging from Harris, where an expired certification was also an issue, that point is not likely to be decisive. Nor is the fact that searches based on LEO's alerts fail to find drugs, even if that happens most of the time. According to police (and the Supreme Court, which essentially has adopted their point of view), dogs that seem to be making mistakes may actually be alerting to traces of drugs so minute that their existence cannot be confirmed. Hence you can never definitively say a police dog erred, even though there are many possible sources of error.

OK, you might say, but the warrant Chavez obtained authorized a search not only of Eckert's truck but of Eckert himself, "to include but not limited to his anal cavity." That was the piece of paper that purportedly permitted Robert Wilcox, an emergency room physician at Gila Regional Medical Center, to order X-rays of Eckert's abdomen and chest; allowed Wilcox and another physician, Okay Odocha, to insert their fingers into Eckert's rectum; gave Chavez license to rummage through Eckert's forcibly produced feces (three times); and made it legal for Odocha to insert a camera into the rectum and large intestine of an involuntary "patient." (Adding insult to assault, Gila later billed Eckert $6,000 for these services.) How could this extensive exploration of Eckert's plumbing possibly have been justified?

In addition to noting Eckert's nervousness, his erect posture, and LEO's alleged alert to the seat where he had been sitting, Chavez's warrant affidavit claimed Green told him "Mr. Eckert was known to insert drugs into his anal cavity." Green made no mention of this in his report, and Eckert denies it, calling it a baseless "rumor." Bobby Orosco, the detective who supposedly saw Eckert roll past a stop sign, did say he told Chavez that Eckert was a "known meth user," but there is nothing in Orosco's report suggesting that drugs might be found in Eckert's anal cavity.

Flimsy as all this seems, Los Angeles defense attorney Ken White, a former federal prosecutor, argues at the blog Popehat that it might be deemed sufficient for probable cause. "I'm not afraid because police officers violated David Eckert's constitutional rights by raping and torturing him because they thought he might have a trivial amount of drugs," writes White (to whom I am indebted for gathering documents related to Eckert's case). "I'm afraid that they might not have violated his rights as defined by the courts, because we have allowed those rights to wither away out of fear and indifference."

George Washington University law professor Orin Kerr, a Fourth Amendment expert, concludes that even if there was probable cause to believe Eckert had drugs up his butt, the procedures performed at Gila Regional Medical Center were so invasive that they "likely" violated the test established by the 1985 Supreme Court decision Winston v. Lee. In that case, the justices rejected court-ordered surgery to recover a bullet from a robbery suspect, finding that the evidentiary value of the bullet was outweighed by the risks of the operation and the injury to the suspect's "dignitary interests in personal privacy and bodily integrity."

But here's the thing: Kerr isn't sure Winston means Eckert's constitutional rights were violated when he was. While the procedures inflicted on Eckert were an even greater indignity than the surgery addressed in Winston, the physical risks were smaller, and the evidentiary value of the drugs (if only they had existed) was much greater than the evidentiary value of the bullet. In fact, the entire case against Eckert (if it had ever been brought) would have hinged on what the cops found in his digestive tract. Who can say how the courts will decide to weigh those factors?

If I were doing the analysis, the government's purported interest in discovering arbitrarily proscribed substances in Eckert's guts would weigh nothing at all. There is no need to search for contraband in the absence of prohibition, which forbids actions that are not crimes while legalizing actions that are. The appalling assault on David Eckert is just the latest example.