This is the Zodiac speaking

The zodiac is a serial killer who committed his crimes in the United States from 1968 to 1969.
The Zodiac himself attributed to himself 37 murders, but this was not confirmed by any facts and at the moment it is proved that he committed only 5 murders and two more survived after his attack.
The zodiac is often called the Jack the Ripper of the XX century due to the fact that he, like his British "colleague" was not caught.
It is believed that the zodiac had a mental disorder - he wished to interest himself. And to satisfy this desire, he used letters that he sent to various publications. Only some of them were not quite ordinary - they were cryptograms.
The zodiac made four attacks.
On December 20, 1968, he shot two young men (Betty Lou Jensen and David Faraday).
In 1969, on Independence Day (July 4), he shot another pair. Only this time, a girl (Darlene Elizabeth Ferrin) was killed, and a guy (Michael Renault Magow) survived, even despite three gunshot wounds.
On September 27, 1969, he tried to kill another couple. Again, the girl (Cecilia Ann Shepard) passed away, and her young man (Brian Calvin Hartnell) survived.
The last proven victim of the Zodiac on October 11, 1969 was a taxi driver (Paul Lee Stay), whom he shot with a shot in the back of the head.
The zodiac sent about 20 letters between 1969 and 1974 (the authorship of the 1978 letter has not been proved). He mainly wrote to newspapers. Of interest to us are just a few of them.
After two attacks, the editors of the three San Francisco newspapers — Vallejo Times-Herald, San Francisco Chronicle, San Francisco Examiner — received the same (with slight differences) letters. In addition to letters, there were also three different cipher programs - for each edition its own.
Letters began very “sweetly”: “Dear editor. I’m the killer of two teenagers last Christmas ... ” He went on to talk about things that only the police could know in order to prove that he really is the one he claims to be. Then it was said that part of the cipher was attached to the letter, the remaining two were sent to other publications. Then the Zodiac demanded to publish these parts of the ciphers on the front pages of newspapers, otherwise he would travel around the area and kill passers-by.
Requirements fulfilled. Encryption sent for decryption to the National Security Agency.
But the message was decoded earlier - the school teacher Donald Harden and his wife coped with the task in just a few minutes.
Many people like to say that the NSA experienced significant difficulties in decrypting the message and therefore Harden was able to provide an open message earlier. This is not true. It's just that the NSA did not consider the Zodiac business important, and the ciphers fell into the usual queue.
Here, in fact, these same ciphers:
Vallejo Times-Herald

San Francisco Chronicle

San Francisco Examiner

These ciphers are not independent messages, but only parts of one large one.
The decrypted message reads:
i like killing people because it is so much fun it is more fun than killing wild game in the forrest because man is the most dangerous anamal of all to kill something gives me the most thrilling experence it is even better than getting your rocks off with a girl the best part of it is that when i die i will be reborn in paradice and all the i have killed will become my slaves i will not give you my name because you will try to sloi down or stop my collecting of slaves for my afterlife ebeorietemethhpiti
I love killing people because it's fun. this is even more fun than killing on a hunt in the forest, because man is the most dangerous animal. killing all of them gave me the most exciting experience. it's better than fucking a girl. the best part of it is that when I die, I will be reborn in paradise, and all those whom I killed will be my slaves. I will not give you my name because you will try to slow down or stop my gathering of slaves for my afterlife. ebeorietemethhpiti
Decryption of two more ciphers is given on some sites, but I could not find evidence, except on these sites, that the letters really existed.
There are three more letters with ciphers.
The last in terms of chronology and least interesting, in my opinion, was received on June 26, 1970 by the editors of the San Francisco Chronicle. In this letter, the zodiac says that he will punish the inhabitants. With the help of a bomb, he intends to blow up a school bus. He buried the bomb and, in order to find it, attached a card and a code.
The bomb was not found, and the bus was not blown up. This code has not been disclosed.

On November 8, 1969, the editors of the “beloved” newspaper of the Zodiac San Francisco Chronicle received a letter containing a postcard in which he complained of loneliness and asked to publish a new message on the editorial. The wish was fulfilled.

A code was attached to the card.

And this code was not disclosed.
A letter followed in which the Zodiac wondered if the cipher sent earlier had been cracked.
And then suddenly his name is called. Although it is said too loudly - he hides it behind the next cipher.

Could not find out the name.
Then letters followed, but nothing good could be learned from them.
The zodiac remained at large. At the moment, he most likely has already died, but left his riddles. It is possible that they have no solution and are written in order to constantly stir up interest in ourselves, but most likely "we will never know."
PS If someone is interested in the entire history of the Zodiac, then there are many sites on the network dedicated to him, books and films have been written as well (the last of them was in 2007 with Robert Downey Jr., Jake Gyllenhall and Mark Ruffalo) which tells how twice the zodiac managed to get away from the police.