"We asked the family, and they said he did it quite often," said Lt. Craig McGuire of the St. Charles County Sheriff's Department. "Nobody really knows what it means. It's kind of like private diary writing."
Ricky McCormick
It probably means nothing — like the bafflegab stuff John Nash wrote in “A Beautiful Mind”.
Ah yes...I think I’ve cracked the code.
And no, I’m not telling where the gold is buried.
It may not be code at all, but simply short hand.
Just like BRB,ROFL,etc.
Thinking inside the box:
“They have tried just about all of the standard routes of cryptanalysis that the top experts use, he said, so the FBI didn’t bother asking for help from the government’s chief code-breaking agency, the National Security Agency, and its high-powered computers in the Maryland suburbs just outside the capital.”
Let’s see: We can’t figure it out, we tried all the standard methods without success so we’re going to ignore the NSA - the premiere, best funded spy agency on the planet. Makes sense to me.
For my part, it’d be easier from the start with a transcription of the letters and numbers to typeface so one could more easily look for patterns eg. is that an “r” an “n” ... ? If in doubt you can refer to the original but a text version would be useful ... ;-)