What's the origin of the phrase "Baader-Meinhof phenomenon"?

The "Baader-Meinhof phenomenon" is that weird experience where you learn of a new word or phrase and then suddenly see it crop up everywhere.

At the time of writing, the Wikipedia entry for "frequency illusion" said:

The name "Baader-Meinhof phenomenon" was coined in 1994 by an online message board user, who, after mentioning the name of the German terrorist group Baader-Meinhof once, kept noticing it, and posted on the forum about their experience. This led to other readers of the message board sharing their own experiences of the phenomenon, leading it to gain recognition. It was not until 2005, when Stanford linguistics professor Arnold Zwicky wrote about this effect on his blog, that the name "frequency illusion" was coined.

But, crucially, there were no citations to support this supposed origins.

A quick footle round the Internet led me to the Dictionary.com entry which said:

The name of the phenomenon is thought to have been coined by Terry Mullen, who explained his experience with it in a 1994 letter to a Minnesota newspaper.

Interestingly the date is the same, but it is now credited to a letter to a newspaper rather than a forum or message board.

A 2005 blog post about the Baader-Meinhof phenomenon contains a comment which purports to be from Mullens.

I coined the term “Baader-Meinhof Phenomenon” 20 years ago, or so. [...] I alerted the ‘public’ to the Baader-Meinhof Phenomenon through a series of letters I submitted to the “Bulletin Board” in the St. Paul Pioneer Press. I submitted them under the pen name “Gigetto on Lincoln,” a reference to my wheaten terrier named Einstein, nicknamed Gigetto.

We can see now where Wikipedia gets its assertion that it was an "online message board" as they were frequently called "Bulletin Boards" - but this appears to have been a newspaper-based board.

In 2019, there was a short online discussion talking about the origin of the phrase.

The Dread Pirate Bob

@RandomlyBob

Allow me to introduce you to Dan Kelly, formerly the St. Paul Pioneer Press feature editor who published the original reader submission naming the Baader-Meinhoff Phenomenon. He tweets as @BBonward.

Ben Zimmer

@bgzimmer

Now on @LanguageLog: "Frequency illusion," a coinage of Arnold Zwicky, has made it into the @OED: "a quirk of perception whereby a phenomenon to which one is newly alert suddenly seems ubiquitous." languagelog.ldc.upenn.edu/nll/?p=42180

---

---

Ben Zimmer

@bgzimmer

Replying to @RandomlyBob@RandomlyBob @BBonward Very cool! But will we ever know the real name of the reader known as "Gigetto on Lincoln," who wrote that submission? Lexicographical glory awaits...

---

That led me to the St. Paul Pioneer Press new Bulletin Board.

From March of 1990 until October of 2016, Bulletin Board ran every day in the St. Paul Pioneer Press. Now it is an independent production, running online, here at BBonward.com — and on Sundays in the Pioneer Press (twincities.com).

Aha! With that information, I found the original article from 1994!

So I corrected Wikipedia.

Now, does anyone have a scan of the original paper?