Analysis of the note and the language contained within it, tends to indicate that it was written by a female.
Listen carefully! We are a group of individuals that represent a small foreign faction. We do respect your bussiness but not the country that it serves. At this time we have your daughter in our posession. She is safe and unharmed and if you want her to see 1997, you must follow our instructions to the letter.
You will withdraw $118,000.00 from your account. $100,000 will be in $100 bills and the remaining $18,000 in $20 bills. Make sure that you bring an adequate size attache to the bank. When you get home you will put the money in a brown paper bag. I will call you between 8 and 10 am tomorrow to instruct you on delivery. The delivery will be exhausting so I advise you to be rested. If we monitor you getting the money early, we might call you early to arrange an earlier delivery of the money and hence a earlier delivery pick-up of your daughter.
Any deviation of my instructions will result in the immediate execution of your daughter. You will also be denied her remains for proper burial. The two gentlemen watching over your daughter do not particularly like you so I advise you not to provoke them. Speaking to anyone about your situation, such as Police, F.B.I., etc., will result in your daughter being beheaded. If we catch you talking to a stray dog, she dies. If you alert bank authorities, she dies. If the money is in any way marked or tampered with, she dies. You will be scanned for electronic devices and if any are found, she dies. You can try to deceive us but be warned that we are familiar with law enforcement countermeasures and tactics. You stand a 99% chance of killing your daughter if you try to out smart us. Follow our instructions and you stand a 100% chance of getting her back.
You and your family are under constant scrutiny as well as the authorities. Don't try to grow a brain John. You are not the only fat cat around so don't think that killing will be difficult. Don't underestimate us John. Use that good southern common sense of yours. It is up to you now John!
She was young and beautiful. But now she is battered and dead. She is not the first and she will not be the last. I lay awake nights thinking about my next victon. May'be she will be the beautiful blond that babysits near the little store and walks down the dark alley each evening about seven. Maybe she will be the shapely blue eyed brunett that said xxx no when I asked her for a date in high school. But maybe it will not be either. But I shall cut off her female parts and deposit them for the whole city to see. So dont make it to easy for me. Keep your sisters, daughters and wives off the streets and alleys. Miss Bates was stupid. She went to the slaghter like a lamb. She did not put up a struggle. But I did. It was a ball. I first pulled the middle wire from the distributor. Then I waited for her in the library and followed her out after about two minutes. The battery must have been about dead by then. I then offered to help. She was then very willing to talk to me. I told her that my car was down the street and that I would give her a lift home. When we were away from the library walking, I said it was about time. She asked me "about time for what". I said it was about time for her to die. I grabbed her around the neck with my hand over her mouth and my other hand with a small knife at her throat. She went very willingly. Her breast felt very warm and firm under my hands. But only one thing was on my mind. Making her pay for all the brush offs that she had given me during the years prior. She died hard. She squirmed and shook as I chocked her. And her lips twiched. She let out a scream once and I kicked her in the head to shut her up. I plunged the knife into her and it broke. I then finished the job out cutting her throat. I am not sick. I am insane. But that will not stop the game. This letter should be published for all to read it. It just might save that girl in the alley. But that's up to you. It will be on your conscience. Not mine. Yes I did make that call to you also. It was just a warning. Beware....I am stalking your girls now.
Chief of Police Enterprise.
This analysis is not pushing the idea that the author of the Riverside communications was a female, simply considering it a possibility based on the language used - particularly within the 'Confession' letter and Riverside 'Desktop Poem'.
The 'Confession' letter author appears to be reveling in the murder and demise of Cheri Jo Bates, a trait not exhibited by the Zodiac Killer, who not only never mentioned his victims by name, but didn't dwell on the nature of the murders themselves. Here, the author is positively wallowing in the details of their achievement, opening with the lines "She was young and beautiful. But now she is battered and dead". In addition to being morally bankrupt, the author is going out of their way to exhibit a spiteful and malicious streak in the tone of the letter. Providing details of the crime to prove their connection to it, which they ultimately failed to do, appears of secondary importance to the author.
Scouring any piece of text to discover the gender of its author is similar to handwriting comparison - it's subjective and dependent on the observer - and therefore cannot be scientifically validated. This is important to remember when reading the following observations. Would a male individual have used the language contained within the 'Confession' letter? Just like the JonBenet Ramsey ransom note, the author appears to be selling a story - how "the shapely blue eyed brunett said no when I asked her for a date in high school" or maybe they will kill "the beautiful blond that babysits near the little store and walks down the dark alley each evening about seven". Phrases such as "the shapely blue eyed brunett", "the beautiful blond that babysits near the little store", "she went very willingly. Her breast felt very warm and firm under my hands", "keep your sisters, daughters and wives off the streets and alleys" and "it just might save that girl in the alley. But that's up to you. It will be on your conscience. Not mine", raises some questions as to the gender of the 'Confession' letter typist, who is adding superfluous detail into the story behind the murder of Cheri Jo Bates. In addition to this, making sure we understood that 'he' was rejected "by the shapely blue eyed brunett" and was "brushed off" by Cheri Jo Bates many times in 'his' pursuit of a heterosexual relationship.
For those who believe a Riverside connection to the Zodiac Killer, another factor must be considered. Despite the addresses of the Bay Area victims being widely publicized in the newspapers, not once did the Zodiac Killer write to the family members of the victims, such as David Faraday, Betty Lou Jensen and Darlene Ferrin, to name but three - as typified by the author of the Joseph Bates letter, in what can only be described as a cruel and unnecessary act. The mailing of the Joseph Bates letter, again exemplified the callousness of an individual who seemingly bathed in the misery of the murder itself, something evidently absent from the Zodiac communications.
Are these observations, particularly regarding the 'Confession' letter, suggestive of a female author, or a male of effeminate tendencies or inadequacies who just got "brushed off". Or possibly a complete stranger. Your thoughts on either the 'Confession' letter or the JonBenet Ramsey ransom note would be welcome.