'Today, when I think about all the different types I met in that excuse for a penitentiary, this man remains my most uncomfortable memory'. Striking words from a convicted serial killer, who in 1961 became one of America's most wanted fugitives, appearing on the FBI's Ten Most Wanted list. That man was Edward Wayne Edwards, and the man he was talking about was Donald Lee Bujok, promulgated as a prime candidate for the murders of five people in Northern California in the late 1960s by Zodiac researcher Kevin Robert Brooks. This extract was taken from an Edward Edwards autobiography entitled 'Metamorphosis of a Criminal', and left you in no doubt that there was more to Donald Lee Bujok than could possibly be imagined.
The penitentiary Edward Edwards was referring to was Old Montana State Prison, approximately three and a half miles west of Deer Lodge. Donald Lee Bujok had spent eleven years at the prison, serving time for the brutal slaying of Deputy Otto Fossen, who was shot five times in the neck and chest in the small town of Joplin, Montana, on October 5th 1957.
Built in 1871, Old Montana State Prison suffered badly with overcrowding, and prisoners daily life mirrored the bleak walls that confined them. The only solace was sought through work related activities and occasional visits to the W.A. Clark Theater, built in 1919 under the governance of Warden Conley. It seated around 600 and hosted a variety of events, that included traveling theater groups, movies, concerts and religious services, providing temporary relief to inmates, who for the most part relied heavily on introspection to wile away the harsh realities that became an everyday occurrence.  
Donald Lee Bujok was no exception to this rule, performing many jobs within the prison, notably a kitchen clerk, upholsterer and garment maker, but in an attempt to escape his reality may have ascended to an altogether different level of existence, driven by a fascination for Egyptian literature and science fiction, apparent in the striking memoirs of Edward Wayne Edwards. Donald Lee Bujok, strangled by the rigors of daily life in prison sought his escape into the non material realm of fantasy, embracing an afterlife, that would eventually be realized a few years later in the very real world of Northern California, one dark December night in 1968.
The shadow of Old Montana Prison became the embodiment of all things evil, when the headlights of the car driven by Donald Lee Bujok flickered across the dark twisting road of Lake Herman on December 20th 1968 and his route to paradise, that he had sought for eleven years, was just moments away, Sadly it came at great cost and the paradise sought by the Zodiac Killer, was the paradise lost by so many, in the the wake of Northern California's most reviled and elusive killer. A chapter that has left its mark for over four decades and one that began in memories recalled within the writings of Edward Wayne Edwards autobiography, Metamorphosis of a Criminal.  
Kevin Robert Brooks has examined in depth the early life of Donald Lee Bujok, that may have seeded the very inception of the Zodiac Killer, through to the numerous letters and cards he mailed to the San Francisco Chronicle, along with other associated publications, and believes his search for America's most notorious serial killer may be coming to an end.
One such letter he has analyzed may possibly have marked the final chapter of this story, sent to the San Francisco Chronicle on January 29th 1974, that of the 'Exorcist' letter, believed by many to be the Zodiac Killer's final letter and impending epitaph.               

night then move on to kill again, until I end up with a dozen people over the weekend".
In both examples the threat of non publication would result in further consequences. On July 31st 1969 the threat was murder, so why should it be any different here, thereby completing the phrase "PS if I do not see this note in your paper, I will do something nasty, which you know I'm capable of doing. To Kill".
Another striking comparison can be found in authenticated correspondence Donald Lee Bujok mailed to the Billings Gazette in Montana on June 2nd 1974, just over four months after the receipt of this letter. 
It also ridiculed the idea of demonic possession stating "If his work was impressive enough, we could then extend his services to Deer Lodge. Just think of the money we could save by releasing de-possessed people who would no longer require confinement" and "Exorcism? Evil Spirits? Possession? I have a word to describe this so called phenomenon, but I'll use the initials BS, because I don't think the editor would print my expletive."

On October 5th 1970, exactly thirteen years after the murder of Deputy Otto Fossen in 1957, '13 bullet holes' punched through the 13 Hole Postcard arrived at the San Francisco Chronicle with the words "FK I'm Crackproof, What is the price tag now?". But this is another story.   http://www.zodiacciphers.com/zodiac-news/thirteen-holes-in-time
Thanks to Kevin Robert Brooks. 
Below is a sketch created by Kevin Robert Brooks, taken from a photograph of Donald Lee Bujok aged in his late 40's.

In a previous article it was shown how Kevin Robert Brooks and his team of investigators had formulated a plausible reason behind the design of the 'Button Letter' and its associated Phillips 66 Petroleum Map.
The Button Letter was mailed to the San Francisco Chronicle on June 26th 1970, accompanied by a map of San Francisco and its vicinity. On the map, the Zodiac Killer had added his traditional crossed circle centered over Mount Diablo, however, on this occasion he added the numbers 0,3,6 and 9 around its circumference, or more specifically, on the cardinal points. Crucially though, he also added a directional marker on the North facing compass point as a positional indicator. 

If we take the crossed circle and superimpose it over the center of Roundup, Montana, the directional North marker points directly to two adjacent counties. Firstly Petroleum County and secondly Phillips County, giving us the very real reason behind his choice of map in the first place, and the birth place of America's most elusive serial killer.

Kevin Robert Brooks has recently released two videos on Youtube, outlining his case for Donald Lee Bujok as the man behind the mask, we only know as the Zodiac Killer. The first was outlined in the previous article: Thirteen Holes in Time. The second will be described here.

On June 26th 1970, the Zodiac Killer mailed the Button letter to the San Francisco Chronicle, upset that the citizens of San Francisco had not complied with his wishes to wear his Zodiac buttons, claiming he had killed a man in a parked car with a .38. He also designed a 32 symbol code - the fourth in a series of cryptic messages - of which only the first, the 408 Cipher was ever solved. Also accompanying the letter, was a Phillips 66 road map of San Francisco and Vicinity. On this map the Zodiac Killer had emblazoned his crosshairs symbol, centered over the peak of Mount Diablo, along with a brief segment of writing, stating it was to be set to Magnetic North.

The Zodiac Killer appeared a master of misdirection and false promises, placing the Bay Area into panic by proclaiming he would target a school bus and "pick off the kiddies as they came bouncing out".  A threat that fortunately never materialized. His threat to use a bomb in several letters, including this Button letter, also appeared to carry little weight, other than to continue his campaign of terror using a pen, as opposed to a bullet.    

The key to this mystery lies hidden in plain sight. In this instance, the clue lies in the map itself - a 1969 version of the Phillips 66 road map. The Phillips Petroleum Company (1917) was founded in Bartlesville, Oklahoma by brothers Frank and Lee Eldas Phillips, becoming an iconic American brand, the name in part, derived from testing undertaken on US Highway 66 in Oklahoma.

Kevin Robert Brooks takes us to the county seat of Roundup, Musselshell County, Montana where Donald Lee Bujok was born. This area of personal significance is where the Zodiac Killer was directing us all along. All we have to do now, is place the center of the Zodiac crosshairs over the area of Roundup, Musselshell County and follow the arrow placed at the top of the Zodiac crosshairs (set to Mag N,) and see where it takes us.
The two immediate counties above Musselshell County, are Petroleum County (established in 1925) and Phillips County (established in 1915).

If we take the crossed circle and superimpose it over the center of Roundup, Montana, the directional North marker points directly to two adjacent counties. Firstly Petroleum County and secondly Phillips County, giving us the very real reason behind his choice of map in the first place, and the birth place of America's most elusive serial killer. On the Phillips 66 Petroleum Map, the Zodiac Killer added a notation that his design "is to be set to Mag.N". Taken to be Magnetic North. In 1970, Magnetic North was approximately 16.5 degrees. If we adjust the crossed circle accordingly by 16.5 degrees, it becomes even more significant, with the directional marker passing exactly over both county seats of Winnett and Malta, shown on the map above.
The county code numbers of Petroleum County and Phillips County are 55 and 11 respectively. These totaled up equal 66, to provide yet another interesting feature, bearing in mind the Phillips 66 Map.
Thanks again to Kevin Robert Brooks. ​

Saturday in the quiet town of Joplin, Montana, seemed like any other day back in 1957, but this was to turn out to be no ordinary day for the residents of Liberty County, when the lives of two men on a collision course were about to change forever, in which one was to emerge and possibly become the most notorious killer in American history.
Hichhiking his way from Roundup, Montana in search of employment in Shelby, Donald Lee Bujok entered the town of Havre, situated just over 50 miles east of Joplin. Here he made a decision that was to turn out to be life changing, when he stole a Ford Monarch car outside of Buttrey's Department Store at approximately 8.15 am on the morning of October 5th 1957.
Shortly afterwards, the owner of the car contacted the local deputy, who in turn relayed the facts to law enforcement in Chester, approximately one hour's drive west of Havre, that the suspect may possibly be heading in their direction - and indeed he was - approaching along Highway 2, towards Joplin.
Deputy Otto Fossen (65), a 30 year veteran of the Chester Sheriff's Department was sent to investigate, and located the stolen car just a short ten minute drive east of Chester in the small town of Joplin. The vehicle had a flat tire.
Deputy Otto Fossen questioned a manager at the Farmers Union Elevator to see if he had noted anything suspicious in the area, whereupon he noticed some activity in the area of Highway 2, Joplin Road, spotting a man being led away from a car. He was now to make a decision that would forever leave its mark in Joplin, but unfortunately, for all the wrong reasons.
He approached the suspect in his car, but things soon turned sour. A man determined to reach his destination that day and a deputy simply performing his duty, had lit the touchpaper that exploded into a powder keg of tragic consequences, as a scuffle ensued between the two men while entering the patrol car of Deputy Otto Fossen. Five shots shattered the tranquil Montana air. Moments later, a man exited the car and fell into the nearby ditch. Sadly it was Deputy Otto Fossen, fatally struck five times to the neck and chest and he died shortly after reaching hospital.      

The senseless slaying of Undersheriff Otto S Fossen on October 5th 1957, occurred exactly 13 years prior to the 13 Hole Postcard, mailed to the San Francisco Chronicle newspaper. In this correspondence, if we believe it to be genuine, the Zodiac Killer clearly makes the date evident in the top right corner, Mon, Oct 5 1970, as to signify its relevance, along with punching 13 holes through the face of the card.
Kevin Robert Brooks, an avid Zodiac researcher and author of the upcoming book 'Zodiac-The Montana Connection', has noted the significant emphasis the author places on the date, the number 13 and the punch-holes accentuated within its design.
The Zodiac Killer was telling us that this particular date was personal to him, being the anniversary of the shooting of Deputy Otto Fossen back in 1957, stating on the card 'Its just one big thirteenth', alongside the number 13 itself.
Donald Lee Bujok's version of events back in 1957 to people he knew, claimed self defense, in that Deputy Otto Fossen had pistol whipped him and he was acting to defend himself. On the 13 Hole Postcard, a conductor's punch was used to forge the holes in the card. Kevin Robert Brooks believes that Donald Lee Bujok, a former army veteran and railroad worker, used these punch-holes to mark each year since the tragic events of 1957 and the day Donald Lee Bujok, by all accounts, first ventured into the world of first degree murder.      

This article was written with express permission from Kevin Robert Brooks, author of the 'Zodiac The Montana Connection'. 

Although the last confirmed murder attributed to the Zodiac was the slaying of taxi driver Paul Stine on October 11th 1969, the killer continued his onslaught towards the citizens of Northern California and beyond in the form of threatening and taunting letters, the like of which authorities had never experienced previously, driven by an overwhelming desire to keep the fear factor well and truly alive in the psyche of everyday people.
Driven by the art of humiliation and misdirection he led the investigative bodies on a piece of string, complimented by an inordinate amount of good fortune, to elude capture throughout his manifesto of evil during the late 1960s and early 1970s.
Although his correspondence to the newspapers eventually dwindled away, it may be that two of his later letters, despite being shorter by comparison, held the biggest key to unraveling, or at the very least guiding us into the very footprints of a killer.
The Exorcist Letter sent to the San Francisco Chronicle on January 29th 1974 was closely followed just five days later by the SLA Letter, postmarked February 3rd 1974 - and both letters seemed to offer very little in the way of clues - that is unless you know where to look.
Kevin Robert Brooks steps into the mind of the Zodiac killer, believing he is slowly drawing his suspect out of the shadows and into the light, as one and the same.
On the face of it, little can be gleaned from these two short messages, that is, until you compare these two letters to others, and place them alongside articles sent by Donald Lee Bujok to the Billings Gazette in the 1970s.
In a previous post it was shown that Donald Lee Bujok had mailed numerous literary observations on various social issues of the day to the newspapers, giving us a tantalizing glimpse into the psyche of what drove him and possibly indicated that the author was luring us into a game of 'cat and mouse', thereby toying with authorities, seeing if they could connect the dots between the Billings Gazette articles and the Zodiac paraphernalia that had streamed from the pen of a killer for virtually half a decade.   

In the Billings Gazette he opened up with the statement "I have been reading and hearing all about the Exorcist in Billings", very similar to his superfluity of words in the Exorcist Letter.
On March 22nd 1974, in another letter to the Billings Gazette, he seemed irked by a Dick Tracy horror strip apparently promoting poor moral values, mirroring the Badlands/Citizen Letter, mailed by the supposed Zodiac on May 8th 1974 just one and a half months later, in which he chastised the running of advertisements for the Badlands movie in similar poor taste, as well as parallels to the attack on columnist Marco Spinelli in the Red Phantom Letter on July 8th 1974.
In another article he moralizes over the issues of hunting and the rights of landowners. 

A rival reporter Jane Plumb, who was also pursuing the story after receiving correspondence from the killer, felt she could arrange a meeting with 'The Ripper' for an exclusive.      
Two pilots were made in 1972 and 1973 based on an unpublished novel, called 'The Night Stalker'.
The series also included 'They Have Been, They Are, They Will Be' released on TV September 27th 1974, 'Firefall' released November 8th 1974,  'Horror in the Heights' released December 20th 1974, 'Legacy of Terror' released February 14th 1975,  and ended with 'The Sentry' after twenty episodes on March 28th 1975, just 11 days after Donald Lee Bujok's most recent correspondence with the Billings Gazette. 
The second interesting piece of the article is contained in only one word. Donald Lee Bujok signed the foot of the letter with the word 'Skoal', which is Danish Old Norse meaning cheers or good health, reminiscent of the SLA letter's unusual footnote, stating 'an old Norse word meaning "Kill". 
On the face of it, these articles to the Billings Gazette appear insignificant, until you bear in mind their close proximity to known Zodiac correspondence and the subject matter involved.
This article is courtesy of Kevin Robert Brooks and this is the 'Montana Connection'.

Donald Lee Bujok was born in Roundup, Montana on July 6th 1936 and it was to become a long and tortuous road from boyhood to manhood, for a child that never grew familiar with the concept of fair play from the outset. Due to circumstances beyond his control he was moulded into a future, that even he may not of dared to comprehend, wiling away his time near the banks of the Musselshell River, and in a state synonymous with mountain peaks, the fall circumventing the young Bujok was about to become dramatic to say the least.
Donald Lee Bujok was afflicted early on in his life with a pronounced speech impediment, and schoolchildren were not the forgiving type, resulting in persistent bullying, that only served to marginalize him on his first tentative steps towards the fringes of society. An isolation and rejection that would eventually manifest itself in the most brutal way.

With his court appointed attorney, John D Gillan, standing beside him, Bujok, now 21 years of age, received a murder in the first degree life sentence from District Judge C B Elwell, for the unprovoked and senseless killing of Undersheriff Otto S Fossen (65), gunned down by five bullets to the neck and chest as he was beaten to the draw near Joplin, Northern Montana, on October 5th 1957 at 9.30 am, when he stopped a hitchhiker over an abandoned car.
Bujok then attempted his bid for freedom in Fossen's car, after which an intensive, yet brief manhunt ensued, before the suspect was finally cornered by a group of law officers hiding in a restroom north of Chester, and with no possible exit, and heavily outgunned, his days of freedom were about to come to an end.
Donald Lee Bujok, former army veteran and railroad worker, uttered the words "Guilty your honor" before being led away to serve his time in Old Montana State Prison, that became forever etched in the public psyche for the infamous Jerry's Riot that took place on 16th April 1959.
Deep inside the Montana walls of correction, it appeared that the young adolescent Bujok was learning little of value, becoming a disciplinary problem, having been sent to the hole several times, surrounded by hardened criminals of an even less forgiving nature than the schoolchildren that preceded them. But it was the writings of another prisoner, Edward Wayne Edwards, that etched a belief, that the man who started life ridiculed on an almost daily basis was starting to forge his own manifesto of evil, for an afterlife, that would now take fair play to the next level, but this time he would become its orchestrator.
Donald Lee Bujok served only eleven years of a life sentence, being released from Montana Prison on December 17th 1968, and three days later the Zodiac announced his arrival to the world, as the lonely pullout on Lake Herman Road would testify to one dark night in Northern California.
Kevin Robert Brooks believes that the young boy sculpted as a child, hardened in the walls of confinement and further isolated from the clutches of reality, had now embarked on a mission of evil from which their was no turning back, as his collection for the afterlife was now underway.

One of the key elements to any case is eyewitness testimony - and although it is not always wholly reliable, it does provide certain indicators that cannot be overlooked, when matching a suspect to a particular crime. This is no different in the Zodiac crime committed at Blue Rock Springs Park in Vallejo, where Michael Mageau survived a hail of bullets at point blank range to recount his experience of that dark night back on July 4th 1969. Nearly three months later, came the Lake Berryessa attack on September 27th 1969, in which Bryan Calvin Hartnell managed to 'play dead', to relive his terrifying account of that day's unfolding horror, along with the recollections of Officer Donald Fouke in Presidio Heights on October 11th 1969, a day in which the killer narrowly escaped the clutches of law enforcement but for a critical error, that allowed the murderer of Paul Stine to disappear into the night.

Here we will assess Kevin Robert Brooks suspect Donald Lee Bujok, searching for anything in the victims statements and perceptions of those fateful days, that give rise to a credible link to this suspect, and again, let you decide on the merits or pitfalls of any association.
Initial statements can become elaborated upon in time, so we will take Michael Mageau's early description of his assailant, where he described him as short, possibly 5'8'', heavyset, with a beefy build, but not blubbery fat, around 195-200 lbs, short curly hair in a military style cut, combed up in a kind of pompadour, light brown, almost blond. He was between 26-30 years of age and was not wearing glasses, but made reference to the fact that he could not recall anything unusual about his assailant, other than he had a large face. 

Donald Lee Bujok is pictured below in ninth grade and here on the left in a mugshot taken at Montana State Prison. Note the curly pompadour style hair flicked up at the front, with shorter hair in the more recent picture, yet still turned over at the front.
​When comparisons are drawn from the school yearbook, it can be noted the size of Bujok's face in regard to the other adolescents, as notably larger. Considering Michael Mageau's description was on a dark night, when shadows would have inevitably make objects and faces appear smaller due to a lack of definition, this is an unusual observation.
In addition, the mugshot with glasses superimposed, bears a striking similarity to the famous Zodiac Killer composite sketch.
The brutal stabbings at Lake Berryessa was the only time the killer engaged in any known protracted dialogue, thereby lending to the notion that the murderer may have unwittingly revealed key elements to his identity during his close interaction with surviving victim Bryan Hartnell. 
During his conversation with Bryan Hartnell the killer stated, "I just got out of ......some prison in Montana". Later in an interview with Sgt John Robertson at the Queen of the Valley Hospital, just one day after the attack, Bryan Hartnell tried to recall the name of the prison, "its some double name, like Fern Lock or something," and when aided by Sgt John Robertson saying "It's Lodge", Hartnell replied "Oh yeah,yeah  at least we Know we're together on that." The police sergeant would suggest "Mountain Lodge Prison, or something of that nature," and Hartnell said "Yeah.You know he broke out and had to kill a guard getting out".
On December 17th 1968 aged 32 years, Donald Lee Bujok was released from Montana State Prison in Deer Lodge Valley, approximately 3 and one half miles from the town of Deer Lodge, after serving 11 years for the slaying of Undersheriff Otto Fossen in 1957. Was this the moment in the dialogue with Bryan Hartnell that the impenetrable Zodiac Killer became human for just a brief moment in time, to possibly reveal clues to his identity, that for so long he promised in his cryptic ciphers and later communications with police.
A transcript of Bryan Hartnell's conversation with the Zodiac, stated that the assailant revealed  "I'm on my way to Mexico, I escaped from Deer Lodge Prison in Montana, Deer Lodge. I need some money to get there". 

Approximately 40 minutes after the attack at Blue Rock Springs Park, a call was received by the Vallejo Police Department, allegedly from the killer, from a phone booth at the gas station close to murder victim Darlene Ferrin's home, where the man claimed responsibility for the Lake Herman Road murders and the recent attack at Blue Rock Springs Park.
The police dispatcher who took the call in the early hours of July 5th 1969 was 26 year old Nancy Slover, who described the voice as mature, without accent, who spoke even but consistent, soft but forceful, as if reading from a script. However, it is equally conceivable the killer may have been speaking the way he always did, applying control in the monotone fashion that was now as natural to him as the murderous rampage he had recently embarked upon.
These are the questions Kevin Robert Brooks has wrangled with, in his conviction and search for the truth behind America's  most infamous serial killer. Despite all the correspondence, cryptograms, and cat and mouse games employed by the man labeling himself the Zodiac Killer, could the answer simply lie somewhere three and a half miles west of Deer Lodge, that fell from the mouth of a killer one fateful September afternoon.

The Zodiac Killer mystery retains an unfaltering allure, that has managed to captivate a worldwide audience for more than four decades. When people become entranced with the case, there are many times upon reviewing the postcards, ciphers and wording, that the breath of the killer can almost be felt for a brief moment, when you spot something you think is significant, before it is cruelly snatched away. But it does not stop you trying, in essence to close the book on years of torment for the victims families and friends, which often has unfortunately become lost in the midst of this tragic affair.
Many suspects have been touted as the infamous Zodiac Killer, and most have been effectively eliminated from ongoing scrutiny. However, recently another name has emerged, that of Donald Lee Bujok, promoted from previous obscurity to the forefront of the discussion, by some detailed and extensive research by Zodiac enthusiast Kevin Robert Brooks, who can claim to have felt the breath of a killer more than most.

But can Kevin Robert Brooks convince us that Donald Lee Bujok is the killer. Well that is for you to decide.
As an introduction to this suspect, one must first acquaint themselves with the forerunner to this story, 'Donald Lee Bujok-Zodiac Suspect', which details the thought processes the killer used in the design of the Halloween card.
Bearing in mind the killer is approaching his writings from a rationale different from the norm, the key to cracking his codes, may lie in unconventional thinking, held naturally by very few individuals. 
Kevin Robert Brooks also dissects the Exorcist letter and subsequent S.L.A letter, which he believes are inextricably linked by the word "kill".
It is a widely held belief that the footnote of the Exorcist letter stating  "Me-37 SFPD-0", is a reference to his murder count so far. If we believe that his 'tally' was progressive, who and where are all his victims, and why the three year period of inactivity in correspondence. If the killer was incarcerated during this period, then murder on this magnitude is frankly implausible, if we are to believe the Exorcist letter as genuine Zodiac material.
​However, there is an alternative, in that the killer is revealing his age of 37 years, this time attributing it to Me, and not the Zodiac symbol as in previous writings. 

other schoolchildren, and ultimately becoming socially detached. 
Determined to lay claim to some meaning in life, Donald Lee Bujok joined the army, where in 1954 he was stationed at Fort Ord on Monterey Bay. This posting, according to Kevin Robert Brooks, effectively became pivotal in his later correspondence, manifesting itself  in the construction of The Halloween card and envelope, detailed by Kevin Robert Brooks in a Youtube video and previous article on this site.
But another tantalizing clue lay in something Donald Lee Bujok could have retained from his brief spell at Fort Ord, before his medical discharge - this being the writing paper used at the military base.
This may possibly be the same paper used to author the Zodiac letter, sent to the San Francisco Chronicle on July 31st 1969, described on page 446 of Robert Graysmith's 'Zodiac Unmasked'. That being, it was so thin, that the overleaf became visible, measuring exactly 7 and 1/8 inches by 10 and 1/2 inches, identical to the Fort Ord stationary Donald Lee Bujok would have had access to. But after his early contact to the newspapers, wisely switched materials, in order to protect his identity.
Kevin Robert Brooks, crafted by careful research, is steadfast in his belief that his suspect is the Bay Area murderer, and is now more confident than ever, that the breath of his killer, is the one that condensed in the chill of the Lake Herman Road air on December 20th 1968.

Kevin Robert Brooks has done extensive research into the Zodiac case and firmly believes he has identified the notorious serial killer as Donald Lee Bujok, with numerous interesting 'coincidences' between Bujok's life and the Zodiac letters, but here we will concentrate on his findings regarding the 'Halloween' card, mailed on October 27th 1970 to Paul Avery, a reporter at the San Francisco Chronicle.
Firstly, Donald Lee Bujok had a military background, serving with the Sixth Infantry Division for approximately eight months in 1954.  The 6th Infantry Division of the United States Army was active in World War I, World War II, and the last years of the Cold War. Known as "Red Star", and formerly called the "Sight Seein' Sixth." The 6th Division was reactivated on the 4th October 1950 at Fort Ord, California. There the division remained throughout the Korean War, training troops and providing personnel for combat, but was never deployed overseas as an entity itself and was again inactivated on the 3rd April 1956.
While stationed there, Bujok would have come across the California Veterans Association symbol which looks very similar to the symbol the Zodiac placed on the upper left of the envelope and at the foot of the card once opened (seen here below left).

Kevin Brooks draws you in to the symbol on the left side, believing the lined section with four dots to stand for ZV4F, decoded to: Zodiac is a veteran with 4F, regarding the medical grounds to which Donald Lee Bujok was released from the army. The medical release records indicated issues of mental health, to which Bujok suffered throughout his life.
Classifications are detailed in Wikipedia: "Registrant not acceptable for military service. To be eligible for Class 4-F, a registrant must have been found not qualified for service in the Armed Forces by a Military Entrance Processing Station (MEPS) under the established physical, mental, or moral standards. The standards of physical fitness that would be used in a future draft would come from AR 40-501". link
Also the familiar Zodiac crosshair symbol could be found at the garrison during the time Bujok was stationed there (see below right). It marked the spot for a helicopter landing pad, and this is where he formulated the inspiration that he used in later Zodiac correspondence.

The skeleton's position within the card was possibly portraying memories of his time in prison, in which prisoners were hung by their wrists to the cell bars, as a form of punishment, and similar to how Paul Stine's body was discovered in the taxicab at the Presidio Heights murder scene.
A prison disturbance broke out at Old Montana State Prison in 1959, detailed in an excellent book by Kevin S. Giles. In it he described the punishment meted out by prison guards at the jail, of  "a cruelty that included extortion and beatings, that included blackjacks and iron pipes. Parolees came forward with tales of some convicts being tear gassed in their cells. Others hung Christ like from the bars in the hole, where handcuffs chaffed their wrists until they bled. In this dungeon men lived round the clock on bread and water diets. Stories got out that in some cases they got a surprise meal of pork, purposefully soaked in salt. Thirsty men cried out for more than two cups of tepid water that was allowed to them."  link
On July 26th 1970, the Zodiac Killer would mail the 'Little List' letter, in which he described what he would like to do to his slaves in the afterlife: "Others shall be placed in cages + fed salt beef untill they are gorged then I shall listen to their pleass for water and I shall laugh at them."  Were these images from Old Montana Prison seared into the mind of Donald Lee Bujok, just like the following phrases on the 'Halloween' card. 

"An inmate who particularly stands out in my mind was the man who killed a deputy sheriff. When the posse found him hiding out in an outhouse, he told them "You can't convict me because I swallowed the evidence." He had swallowed the bullets. This demented individual showed an overwhelmingly interest in science fiction and Egyptian literature. He believed that anyone he killed would be his slave in the next life. He was generally disliked and distrusted by the other inmates. I personally felt that he was one of the most deranged and potentially dangerous persons in the prison. You never knew when he was going to erupt.
​Unfortunately, this inmate idolized me, for the simple reason that I had earned the respect of the population- something, deep down, he desperately wanted to do. He had an uncanny knack for making your skin crawl. Today, when I think about all the different types I met in that excuse for a penitentiary, this man remains my most uncomfortable memory."   PDF page 230       
This is possibly where the inception of the Zodiac Killer, along with his inspiration gathered momentum, eventually to be realized during later communications, such as the July 31st 1969 408 cipher and 'Little List letter' mailed on July 26th 1970.
Finally photographs of Donald Lee Bujok wearing military issue glasses, which he often wore in later life, bear an uncanny resemblance to the famous Zodiac composite sketch.
For the full analysis of Kevin Robert Brooks breakdown and theory, on why Donald Lee Bujok is a firm candidate for the Zodiac attacks, please visit here: http://www.youtube.com/watch
He is now waiting on news from the FBI and Napa County for results on the evidence he has submitted, to see if his prime suspect matches DNA and fingerprints held in storage in the Zodiac case files.