This next section is not inferring the Zodiac drew any inspiration from this novel, nevertheless, outlines some unusual coincidences between this work of fiction to several cards and letters the Zodiac mailed, predominantly the 'Halloween' card and the 'Eureka' or 'American Greetings' card.
Kevin Robert Brooks noticed that the 'Exorcist' letter's strange symbolism at the foot of the letter could be rearranged to spell the words, 'To Kill'. These obviously are the first two words of this novel, but also the 'Exorcist' letter contained an extract from The Mikado about a bird, taken from Act II On a tree by a river- a little tom-tit in this case.
The 'SLA' letter was sent on Valentine's Day and the author suggested that 'SLA' was an Old Norse word meaning kill, but it is not.
The Old Norse for kill or slay is 'val'. The underlined section of Paul Averly on the envelope of the 'Halloween' card is 'lav'. This reversed is 'val', tying in nicely with the date, Valentine's Day.
The LAV letters are again present together in the horizontal word SLAVES on the back of the card, but note the three letters at the intersection of the crossed PARADICE and SLAVES running down- they spell RAD,
The incorrect spelling of Paul Avery to Averly points towards LEY, to complete the character BOO RADLEY.
In fact, a local resident by the name of Stephanie Crawford reported she was woken up one night and saw Boo Radley "looking straight through the window at her..... said his head was like a skull lookin' at her".
On the tree around the knothole there are the words PEEK A BOO YOU ARE DOOMED.
The musical score to the original motion picture was composed by Elmer Bernstein, and three of the tracks present are Creepy Caper / Peek-a-Boo, Boo Who and Tree Treasure.
In the book, Tree Treasure was a hiding place in the knothole of a tree, where several items were found including a broken pocket watch, aluminium knife and a ball of twine. These were placed there by Boo, for two local kids, Scout and Jem to discover. The knothole in the tree represented Boo's outlet to the world, with the kids soon realizing that Boo Radley was far from being a monster to be feared.
All the items he placed at intervals in the knothole came in pairs except the twine- there were two packets of chewing gum, two polished coins, two miniatures of children, and the most interesting of all, was a knife and pocket watch both on the same chain. Presumably two items, so Jem and Scout could have one each.
Remember the 'Eureka' card or 'American Greetings' card mailed by Zodiac, very similar to the 'Halloween' card in its design. This correspondence included a photocopy, of not one, but a pair of keys on a chain. A gift from Zodiac or BOO- either way a mysterious character who never revealed himself.
Incidentally, Scout and Jem construct a snowman in the novel, made initially from mud, then layered with snow- a theme many believe lends itself to the racial overtones within the story- although its interpretation is dependent on the observer. A snowman was depicted on the 'Eureka' card, with what appeared to be Groucho Marx imagery on the face.
Jem and Scout built this snowman because of their dislike of a local resident down the street, but their father Atticus told the children to disguise it, because it so resembled the local resident they were poking fun at- so they placed Miss Maudie's hat on it. That resident they hated was called MR AVERY- now that is a coincidence- along with release date of the film: December 25th 1962, in Los Angeles, California. Happy Holidays.