Fun fact, the ZODIAC killer code has been decrypted.

[Dr. Death]

https://zodiackillerfacts.com/news-and-updates/breaking-news-the-zodiacs-340-cipher-has-been-solved/

The real reason why it took so long to decipher was because the killer made a mistake during the encryption process which no one assumed was a mistake.

[Exploding-Man]

That makes a lot more sense than it should.