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).
The author of the Halloween Card envelope also underlined the L, A and V of the misspelled name of Paul Avery, indicating he was a member of the Light Armored Vehicle Division, with the misspelled surname Averly hinting towards his middle name of Lee.
The front of the 'Halloween' card contains the message, "I feel it in my bones, you ache to know my name, And so I'll clue you in", with the card revealing the word BOO! once opened, signifying his name BUJOK. The card was also 'sprayed' with multiple eyes, drawing the observer to another subtle hint left by Donald Lee Bujok, that he was a member of the Sightseeing Sixth Infantry Division.
Donald Lee Bujok was stationed at Fort Ord in the East Garrison close to where this emblem was located in the bottom left corner of the image.
The writing By Gun, By Knife, By Rope and By Fire represented methods employed by prisoners to taunt guards they had held captive during the uprising at the prison on 16th April 1959, which became widely known as Jerry's Riot. Here is an excerpt from Wikipedia "This started a twenty-four-plus hour standoff in which Myles railed openly to the media outside the walls; Alton retired to his cell after an argument with Myles, convinced that no escape was forthcoming; Jones was again allowed to leave the prison to negotiate with Powell and, under orders from the warden, did not return; and the hostages survived repeated threats of death by fire, rope, or knife. The hostages were eventually crowded into three cells, and the frightened men planned to press the thin prison mattresses against the bars to ward off any attack, but they knew the shield would not hold long against fire or at all against the rifles". link
One prisoner, Edward Wayne Edwards, who served alongside Donald Lee Bujok in Montana Prison, would later go on to release a book entitled Metamorphosis of a criminal. This book detailed the harsh living conditions inside the jail and several of its inmates. One in particular caught the eye of Edward Edwards, who he described as his most 'uncomfortable memory' from his time at the Deer Lodge Prison. A prisoner who held the belief that anyone killed by him would become his slave in the afterlife. Here is the crucial extract:
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 interpretation and theories on why Donald Lee Bujok is a firm candidate for the Zodiac attacks, please visit here: He is now waiting on news from the FBI and Napa County for the results regarding the evidence he has submitted, and hopefully discover if his prime suspect matches the DNA and fingerprints held in storage in the Zodiac case files.