This popular police "mindreading" technique is bullshit — but the things that cops say about it are somehow even worse.

Back in December, ProPublica published a fascinating look into the snake-oil industry around Scientific Content Analysis or SCAN, a so-called "law enforcement tool" that purports to help investigators determine whether their suspects lying. This highly-profitable yet totally-dubious training method works through a rigid grammar analysis that relies entirely on the assumption that human brains only ever work in one completely uniform, logical, rational, conscious, and deliberate manner:

With SCAN, Sapir encourages the asking of a simple, open question: What happened? After the person writes a statement, the SCAN investigator looks for signs of deception, analyzing, among other things, pronouns used, changes in vocabulary, what's left out and how much of a statement is devoted to what happened before, during and after an event. Indications of truthfulness include use of the past tense, first-person singular ("I went to the store"); pronouns, such as "my," which signal commitment; and direct denials, the best being: "I did not do it." Signs of deception include lack of memory, spontaneous corrections and swapping one word in for another — for example, writing "kids" in one place and "children" in another.


Sapir likens SCAN to Sudoku, only with words, not numbers, sentences, not squares: "Everything must fit — left to right, and top to bottom."

And of course, there's no consideration for the possibility that someone might be, idunno, nervous or anxious or god forbid under-educated and therefore might respond to this "test" in ways that seem arbitrarily "suspicious."

Yet there are still tons of cops who swear by it anyway — even though, as ProPublica reveals through a comprehensive analysis of SCAN test results, the system has about a 50 percent likelihood of accurately predicting whether a suspect is lying, which is … no better than a random guess.

You'll notice that I said, "whether a suspect is lying," as opposed to "whether or not a suspect is lying." This is — no joke! — a clear indication I am lying, according to SCAN. The Laboratory for Scientific Interrogation, which sells the training for this "process," offers a sample analysis of the Mueller report that hangs on this very discrepancy. It doesn't matter that the "or not" is completely grammatically redundant as it's already inferred by the question of "whether." Nope, according to SCAN, the lack of "or not" means that I and/or Robert Mueller were biased by starting from a preconceived conclusion.

Welp, they got me there.

The whole article is a fascinating look into the shoddy "training" that a lot of American police officers go through, and how it empowers them with a sense of knowledge and righteousness that is completely isolated from objective reality. But my favorite moments come from the interviews that the writers do with police officers who have actually completed this SCAN training. In order to assert their confidence in it, they frequently turn to … curious idioms, that certainly would not hold up to the scrutiny of the program about which they are boasting:

[The suspect's] lawyer asked whether a person's ability to read and comprehend the English language could affect the results of the questionnaire.

"Well … you struggle with the same questions I struggled with when I went through the school, went through the sessions," [the detective] said. "I guess it's kind of like two and two is four. Why is it four? It's two and two is four all over the world. Why it is I have no idea."

I mean there are clearly ways to determine whether two and two four that are hardly more complicated than simply memorizing and repeating what you learned in first grade. (Unless we're coming from a very  post-postmodern perspective in which all language is inherently meaningless, which, erm, also debunks the SCAN method.)

Then there's Sgt. Mark Miller of the Maryland State Police, one of the few people who received SCAN training directly from its creator, Avinoam Sapir, and actually offered to speak with ProPublica on the record. Here's what he had to say:

"[Sapir's] a phenomenal teacher," Miller said. The sergeant called SCAN a "pretty good tool," which he now uses on occasion. "It's like cooking," Miller said. "You might use salt in one dish, in the next you might use salsa."

Salt? Salsa? Tomatoe, Tomahtoe!

Former FBI director James Comey is also quoted in the piece, with a quippy response about SCAN's stupidity that almost makes him seem likeable for a second. Yes, it's that bad.

Why Are Cops Around the World Using This Outlandish Mind-Reading Tool? [Ken Armstrong / ProPublica and Christian Sheckler / South Bend Tribune]

Image via Joshua Rodriguez / U.S. Air Force.