Hunting terrorists with — linguistics!

Can you solve a major terror incident — four brutally slain — using the tools of language analysis?

In the night of January 20, 1969, the ammunition camp of a paratrooper battalion in Lebach, Germany, was attacked. Four of the five guards on duty were killed. Later reconstruction of the crime revealed that two armed men had cut holes in the perimeter fence, forcibly opened ammunition bunkers and taken rapid-fire rifles, pistols, and over 1,000 rounds of ammunition.

Within a few hours the case became a national political issue. The Defence Minister and the Attorney General came to Lebach, and more than 100 reporters from the largest media outlets accompanied them, reporting worldwide on the brutal murder of the soldiers. 130 police officials and detectives sprang into action and followed almost 2500 individual tracks.

In April 1969 the television program “File XY Unresolved” took up the case. The show had started a TV format that was unknown at this time (1967), and was subsequently sold to TV stations abroad, resulting in broadcasts like BBC’s Crimewatch and America’s Most Wanted. XY Unresolved is still running, fifty years later, on German TV and is regularly watched by around six million viewers. Its goal is to shed light on unsolved crimes with the aid of viewers. They provide information by phone or, these days, by Internet. About forty percent of cases shown on the program are solved.

On April 11, 1969, host Eduard Zimmermann devoted much of the show to the Lebach attack. The episode, watched by over 20 million viewers, is available on YouTube, (second part here). It awakened old memories for me. I will tell you why in a moment, but first I must provide some additional background on case.

After the attack the perpetrators started sending letters to the media, claiming to be members of a mafia group and threatening further crimes. Including extortion. They demanded 800,000 Marks from a financial broker in Munich, “to protect against future attacks,” and claimed that similar demands were being made to 86 other persons. “File XY” concluded that the attack in Lebach was clearly intended to prepare the ground for blackmail on a gigantic scale.

A number of the extortion letters were shown on the XY show, and a telephone conversation by a blackmailer was played for the audience. You can listen to it here. In his intro Zimmermann says: “The police has responded to the blackmail game and spoken on the phone with the perpetrators. We have here on tape a recording of one of the blackmailers. The unknown man is without doubt from France. It is critical to learn whether any one of you, ladies and gentlemen, recognize the voice of the speaker.”

The voice in the recording has a very broad French accent, and the speaker makes a number of glaring grammatical errors. For instance, he says: “Drive autobahn Munich-Stuttgart up to km 30… There you deposit bag… We must pay regard to security. Due to our previous experience we must assume that you will bring police…” As mentioned all of this was spoken with a very strong French accent. A couple of viewers phoned in to say which area of France they thought the speaker must be from.

After listening to the recording I called the TV show. I told them I could guarantee that the speaker was not from France, but was in fact a native German putting on a French accent. This was politely registered, and after an hour I received a call from a language expert of the police to discuss my theory. The reason for my suspicion, I told him, was that the choice of words of the speaker, the phrases he used, did not match the accent or the grammatical errors or his accent. For instance: “Wir müssen davon ausgehen…”, which translates to “We need to assume…”, is a common German expression, but one which no elementary foreign speaker would use. There were a number of other phrases which deviated from the general level of speech and the accent, for example the use of present tense instead of future, which is common in German. It was, in my opinion, clearly a German speaker doing a (poor) imitation of a Frenchman speaking the language.

The police linguist discussed the matter with me at some length — mainly asking for my credentials. I told him I had just done A-levels in linguistics and German in Oxford. That was hardly enough for them. I was politely assured that “the theory would be taken into consideration.” At this stage I remember asking him to imagine someone saying exactly that sentence with a thick French accent and grammatical errors to boot (e.g. “we assure theory will be taken into consideration”). You would immediately know this is a native speaker pretending to struggle with the language.

Well, it turns out that the speaker was indeed a native German. He was subsequently caught and convicted of premeditated murder, and given life in prison. If you understand German you can read this summary report of the incident, or this one, published in Der Spiegel a few days after the attack and long before the case was solved.

I should mention that I got one more call from the police linguist, admitting I had been correct in my assumption that it was a German. I gently inquired about the reward—DM 60,000 had been announced. Was I eligible to receive any part of it? No, he said, my help had not been actually used, I had not directly assisted in solving the case. They had spent weeks looking for a French perpetrator. But at least the detective was appreciative of the analysis I had delivered. He said he was the only one who had taken it seriously.

Written by

Frederic Alois Friedel, born in 1945, science journalist, co-founder of ChessBase, studied Philosophy and Linguistics at the University of Hamburg and Oxford.

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