Help needed with cold case

[dotr]

Not the same little slogan, but somewhat similar, speculation, fwiw..rbbm

https://www.psychologytoday.com/ca/blog/shadow-boxing/201810/art-and-the-serial-killer

''In fact, quite a few serial killers have developed their creative talents while in prison, from making origami or choker necklaces to painting serene sunsets. Most renowned, perhaps, is “Killer Clown” John Wayne Gacy, who murdered 33 young men and buried most in the crawlspace under his house. We often see his "Pogo the Clown" self-portraits on serial killer auction sites, along with his “Hi Ho” series of Disney characters.''

 

[Parsnip]

When I read the word “lock’ and then saw the X-X-X formation, I immediately thought about a standard R-L-R combination lock. “Popping a lock” is familiar to me as phrase indicating the opening of a lock without a key. I’ve popped button locks in my house and once or twice a door on an old car, but I wouldn’t necessarily associate it with a combination lock. Also, they are usually indexed with numbers rather than letters. I suppose the I, D, and L could be Roman numerals since they are all capitalized, but then what of the “i’ and “o” (not to mention the fact that IDL is not a readable Roman numeral)? It would really be a stretch to read that as 5-5-1, but maybe?

I also tried writing out the phrase in the old Palmer method script I was taught in the 70’s to see if there could be potential for misreading a letter. It didn’t get me anywhere, but maybe it will trigger an idea for someone else. It does seem likely, given the era, that the letters were handwritten in cursive.

Interesting puzzle! Like others, I hope OP returns to update us!

Moo.