I have magnified the photographed version from the magazine and retyped it below. It almost concurs with the written version by the Argosy magazine. The original photographed version definitely states minutes not minuts, brunett as opposed to brownett, and victon as opposed to victim or victom.
​Up2something from Zodiac Killer Site forum pointed out that the 23rd line was not "I finished the job by cutting her throat" but "I finished the job out cutting her throat," don't on the 7th line was dont, "slaughter" was "slaghter" and "choaked her" was actually "chocked her". The words pertaining to each line is now correct in the photographed version retyped.. 

It has long been debated whether the 'Confession' letter sent on November 29th 1966 was the work of the Zodiac Killer.
In a recent History Channel docudrama about the Zodiac Killer, the typed 'Confession' letter was analyzed, looking for words that may connect the author of the Riverside correspondence with the infamous Zodiac Killer, focusing on words such as "twich" and "squirm". 
Here, we will go much further and analyze the readability level of the 'Confession' letter, and compare it with known Zodiac correspondence. The idea, is that even if the author of each correspondence was deliberately misspelling words or dumbing down the intellectual content in each letter, he should be consistently achieving the same readability level.
If there is some degree of correlation between the 'Confession' letter and the Zodiac correspondence, it may bolster the argument that the two cases are related- including the stabbing of Cheri Jo Bates and the Bay Area murders. 
The readability level of the above text has an average grade level of 17.04 and a median grade level of 16.40.
The November 29th 1966 'Confession' letter has average grade level of 3.80 and a median grade level of 3.97. 
These results were calculated using five tools: the Gunning fog index, the Flesch-Kincaid readability tests, the SMOG grade, the Coleman-Liau index and the Automated readability index. Here is a brief run down of each from Wikipedia and their respective link.

Gunning fog index: In linguistics, the Gunning fog index is a readability test for English writing. The index estimates the years of formal education a person needs to understand the text on the first reading. A fog index of 12 requires the reading level of a U.S. high school senior (around 18 years old). The test was developed by Robert Gunning, an American businessman, in 1952. The fog index is commonly used to confirm that text can be read easily by the intended audience. Texts for a wide audience generally need a fog index less than 12. Texts requiring near-universal understanding generally need an index less than 8.
Flesch-Kincaid readability tests: The Flesch–Kincaid readability tests are readability tests designed to indicate how difficult a passage in English is to understand. There are two tests, the Flesch Reading Ease, and the Flesch–Kincaid Grade Level. Although they use the same core measures (word length and sentence length), they have different weighting factors.
The results of the two tests correlate approximately inversely: a text with a comparatively high score on the Reading Ease test should have a lower score on the Grade-Level test. Rudolf Flesch devised the Reading Ease evaluation; somewhat later, he and J. Peter Kincaid developed the Grade Level evaluation for the United States Navy.
SMOG grade: The SMOG grade is a measure of readability that estimates the years of education needed to understand a piece of writing. SMOG is an acronym for Simple Measure of Gobbledygook. SMOG is widely used, particularly for checking health messages. The SMOG grade yields a 0.985 correlation with a standard error of 1.5159 grades with the grades of readers who had 100% comprehension of test materials. The formula for calculating the SMOG grade was developed by G. Harry McLaughlin as a more accurate and more easily calculated substitute for the Gunning fog index and published in 1969. To make calculating a text's readability as simple as possible an approximate formula was also given — count the words of three or more syllables in three 10-sentence samples, estimate the count's square root (from the nearest perfect square), and add 3.
Coleman-Liau index: The Coleman–Liau index is a readability test designed by Meri Coleman and T. L. Liau to gauge the understandability of a text. Like the Flesch–Kincaid Grade Level, Gunning fog index, SMOG index, and Automated Readability Index, its output approximates the U.S. grade level thought necessary to comprehend the text. Like the ARI but unlike most of the other indices, Coleman–Liau relies on characters instead of syllables per word. Although opinion varies on its accuracy as compared to the syllable/word and complex word indices, characters are more readily and accurately counted by computer programs than are syllables.
Automated readability index: The automated readability index (ARI) is a readability test for English texts, designed to gauge the understandability of a text. Like the Flesch–Kincaid grade level, Gunning fog index, SMOG index, Fry readability formula, and Coleman–Liau index, it produces an approximate representation of the US grade level needed to comprehend the text.

As another guide I used the text from the Coleman–Liau index above to generate an average grade level of 15.69 and a median grade level of 15.72. To check any section of text or the given examples, visit here. 
Here are the results:
The Confession letter 11/29/66 has average grade level of 3.80 and a median grade level of 3.97. 
The Riverside Desktop poem 1966 has average grade level of 3.89 and a median grade level of 4.00.
The San Francisco Chronicle 7/31/69 has average grade level of 8.15 and a median grade level of 8.12.
The Debut of Zodiac letter 8/4/69 has average grade level of 6.73 and a median grade level of 5.96.
The Paul Stine letter 10/13/69 has average grade level of 7.71 and a median grade level of 7.83.
The Bus Bomb letter 11/9/69 has average grade level of 8.56 and a median grade level of 8.69.
The Melvin Belli letter 12/20/69 has average grade level of 6.25 and a median grade level of 5.66.

The readability levels of the 1966 correspondence is notably lower than the initial Zodiac correspondence, although one has to factor in the near three year maturation of the subject, if indeed they are the same individual. But both are extremely low on the scale, indicating the Zodiac Killer and author of the 'Confession' letter were either extremely uneducated, or extremely accomplished at pretending to be uneducated. Whatever the case, there is a notable shift from 1966 to 1969.
​The above enlarged text has average grade level of 16.50 and a median grade level of 16.27, which highlights the difference in readability level the author in Riverside and northern California was operating at, either by intention or not.

https://charactercounttool.com/

It has long been believed the Zodiac Killer may have taken credit for crimes he never committed. One such example was the Modesto abduction of Kathleen Johns on March 22nd 1970, to which he claimed credit, four months later, giving us details about the crime that had already been published in the newspapers. This may also have been the case in the murder of Cheri Jo Bates on October 30th 1966, when one month after the crime, somebody sent typed Confession letters to Riverside Homicide Detail and the Riverside Press Enterprise on November 29th 1966. But were these from the killer, or an elaborate hoaxer.
When a person is manufacturing a story or crime they never committed, they will obviously use material gleaned from the newspapers, but may subconsciously structure details in the letter in the same order they appeared in the newspaper. In addition they may use identical or similar words used by the author of the article. The person may have attempted to present the Confession letter as first hand information, but inadvertently leaked elements of the article into its wording and structure. Here is one such newspaper article released before the Confession letter arrived. 
'Riverside Police say their only clue in the brutal murder of a pretty, 18-year-old co-ed is a man's wristwatch found 10 feet from her slashed body. Officers speculated that while Cheri Jo Bates, a blonde cheerleader, studied Sunday night at the Riverside City College library, her killer disabled her car. Miss Bates' body, stabbed in the back, her throat slashed, was found early Monday under a tree, 100 feet from the car. The ignition key was in place in the compact car, but the distributor and coil wire had been torn loose, police said. Officers said an anonymous caller telephoned saying she had heard a terrified scream Sunday, then a muffled scream, then a car driving away The caller said she had not thought it serious enough to report until Monday.'              

Let us compare this article to the Confession letter, to view any similarities.
#1.The first thing the article details is the 'brutal murder of a pretty, 18-year-old co-ed', in addition to being a 'blonde cheerleader.' The Confession letter opens with 'she was young and beautiful', along with 'maybe she will be the beautiful blond that babysits,' or 'the shapely blue eyed brownett that said no when I asked for a date in high school.'
#2. The article then details the car being disabled. The Confession letter similarly switches to the Volkswagen Beetle, stating 'I first pulled the middle wire from the distributor', but the author retrieves some additional material from later in the article, where it states 'the distributor and coil wire had been torn loose.'
This topic of the 'middle wire' has been hotly debated in many forums, on whether the author of the Confession letter is supplying information only known to the killer. Here is some additional information to help you decide. "The ignition coil is the unit that takes your relatively weak battery power and turns it into a spark powerful enough to ignite fuel vapor. Inside a a traditional ignition coil are two coils of wire on top of each other. These coils are called windings. One winding is called the primary winding, the other is the secondary. The primary winding gets the juice together to make a spark and the secondary sends it out the door to the distributor.
You'll see three contacts on an ignition coil, unless it has an external plug, in which case the contacts are hidden inside the case. The large contact in the middle is where the coil wire goes (the wire that links the coil to the distributor cap." 
https://www.thoughtco.com/your-ignition-system-how-does-it-work
​http://www.1966vwbeetle.com/1966%20Wiring%20Diagram.htm
http://www.carparts.com/classroom/ignition.htm​​
 
#3. The article then mentions how Cheri Jo Bates was murdered: 'Miss Bates' body, stabbed in the back, her throat slashed, was found early Monday under a tree.'  
​The author of the Confession letter again follows: 'I grabbed her around the neck with my hand over her mouth and my other hand with a small knife at her throat,' continuing on to parrot the article 'I plunged the knife into her. Then I finished the job by cutting her throat.'  The article gives the impression Cheri Jo Bates suffered only two wounds, one to the back, one to the throat. The author of the Confession letter equally describes only two strikes with the knife, despite the fact Cheri Jo Bates suffered numerous lacerations to her body, over a prolonged period, and did not 'go to the slaughter like a lamb.'  
#4. The article then details an anonymous caller who 'had heard a terrified scream.'
The Confession letter again mimics this detail: 'She let out a scream once and I kicked her head to shut her up'. Triggered by the anonymous caller, the author of the Confession letter is reminded to state, 'Yes I did make that call to you also.'   

Finally, the author of the Confession letter stated "I first pulled the wire from the distributor. Then I waited for her in the library and followed her out after about two minuts. The battery must have been about dead by then. I then offered to help. She was then very willing to talk to me." None of which actually happened. 
Walter Siebert stated that 'he and a few friends were in the library from 7.15 pm until 9, but did not see Miss Bates, whom they all knew. They said they saw four men dressed in work clothes sitting on a fence across from the spot where Miss Bates' car was found, but they did not know them.'.
These workmen must have been spotted by Walter Siebert and his friends when they arrived at the library at 7.15 pm. The workmen said they saw Cheri Jo Bates by her Volkwagen Beetle, as they were sitting opposite her vehicle, on the fence, but Cheri Jo was not recollected by Walter Siebert & Co that evening. We know Cheri Jo Bates parked her Volkswagen Beetle on Terracina Drive no later than 6.15 pm, and it is assumed it remained there throughout, until it was discovered disabled the following day. The four young men were interrogated by police, stating "they had seen Cheri Jo near her car the previous night". They must have seen Cheri Jo Bates at 6.15 pm, when she parked up to enter the library. They do not mention to police anybody tampering with the Volkswagen Beetle, anybody assisting Cheri Jo Bates, or Cheri Jo Bates experiencing car trouble. They fail to see anything suspicious, including hearing any commotion or screams from the alleyway. This totally negates the claims issued by the author of the Confession letter, and reinforces the idea the author is simply mimicking what they have read in the newspapers.
So was the author of the Confession letter the killer. I will let you decide.  

CHERI JO BATES-MINUTE BY MINUTE
CHERI JO BATES-MINUTE BY MINUTE [PT2]
​CHERI JO BATES-THE COMPLETE EYEWITNESS TIMELINE

The murder of Cheri Jo Bates outside the Riverside City College Library on October 30th 1966, may have been the day the Zodiac Killer under this moniker, started his campaign of terror. Although it would be at least one month before his typed 'Confession' letter surfaced with the threat of more to come. Five months later, on April 30th 1967, a further three letters sent to the Riverside Police, Riverside Press Enterprise and more chillingly Cheri Jo Bates father, suggested that this killer was not going to stop anytime soon.
His letters were signed off with what looked like a Z symbol, but as yet authorities were a long way from finding out, this may have been the very inception of the Zodiac, the 'calm' before the storm of Lake Herman Road and beyond.
What, if anything, lies within the Confession Letter to suggest this declaration of murder was in any way related to the other crimes that began on December 20th 1968, just over two years later.
It has been previously pointed out that the author of the 'Confession' letter used the wording "She squirmed and shook as I choaked her. And her lips twiched". This having striking similarities to the 'Little List' letter the Zodiac Killer mailed on July 26th 1970, in which he stated "Some I shall tie over ant hills and watch them scream + twich and squirm."
But more apparent is the egocentric nature displayed in the 'Confession' letter, that he maintains throughout his correspondence to the authorities, right through to the Exorcist Letter mailed on January 29th 1974, revealing character patterns of his own unique writing style. His extreme use of the word 'I' appears no less than 19 times, along with his use of 'me', 'my' or 'mine', a further 12 times in this short letter comprising of 423 words. So in total, a reference to himself appears 31 times. That is 7.33% or once every 14 words, and something we were going to get accustomed to over the following eight years.
The 'Bus Bomb' letter, 'Little List' letter and 'Melvin Belli' letter are further examples of the Zodiac Killer's compunction to constantly refer to himself as the focus of attention within his writings. In the Melvin Belli Letter this occurs 16 times, within the body of text containing 134 words, that is 11.94%. The Little List Letter contains 12 in 178 words, at 10.07% and the Bus Bomb Letter is equally high in frequency.   

In a previous article http://www.zodiacciphers.com/1/post/2013/10/the-phantom-murders.html , it was suggested that if the diagram at the foot of the Bus Bomb Letter, received one day after the Dripping Pen Card on November 9th 1969 was indicating murder sites. then by elimination there must have been two individual murders in August along the remaining lines shown  If so, then the Zodiac Killer was not claiming the Riverside attack on Cheri Jo Bates on October 30th 1966, despite part indicating its inclusion under the Zodiac banner, by signing off his Bates Letters on April 30th 1967 with a Z.  
However, if the Bus Bomb diagram was not referring to murder zones, then that leaves us another option for the months of December, July, August, September and October, indicated on the Dripping Pen Card.
The murders of Betty Lou Jensen and David Faraday in December, Darlene Ferrin in July, Cecelia Shepard in September and the murders of Paul Stine and Cheri Jo Bates, both in October, would now leave six murders of the seven accounted for and cementing the Riverside attack as a Zodiac crime. The seventh victim would still be, as yet undetermined. The Hood and Garcia murders would still remain a possibility, since they occurred on February 21st 1970, with the Domingos and Edwards murders on June 4th 1963 falling into the 'Pre-Zodiac' timeline, but not completely ruled out on this basis.
The Zodiac Killer in the 'Los Angeles' letter on March 13th 1971 claimed "I do have to give them credit for stumbling across my riverside activity, but they are only finding the easy ones, there are a hell of a lot more down there."
This may or may not be the case, but the murder of Cheri Jo Bates on October 30th 1966 is one crime, that in many respects has the hallmark of the Zodiac Killer stamped all over it.