On October 13th 1969 the first wanted poster was released to the public concerning the murder of Paul Stine in Presidio Height two days earlier. On January 29th 1970, the Yellow Cab Company put up a thousand dollar reward for any information leading to the arrest of the Zodiac Killer. In addition, the Teamsters Union which represents the Yellow Cab Company were reported in the San Francisco Chronicle to be considering offering a further reward on February 8th 1970 in the case of Paul Stine and Charles Jarman (another taxicab murder victim).

​Then came the murder of Sergeant Brian McDonnell (44) on February 16th 1970, who suffered devastating and sadly fatal injuries when a bomb packed with 1 1/2 inch fence staples exploded on an outside ledge of Park Police Station in the Upper Haight neighborhood. Almost immediately a reward of $5,000 was offered for information leading to the arrest of the perpetrator or perpetrators connected to this crime, authorized by Mayor Joseph Alioto on February 17th 1970, who stood on the ruins of Park Police Station and offered the money for the capture of the "maniacs" who bombed it. This total very quickly snowballed to $35,000 when the San Francisco Examiner newspaper added a further $5,000 to the reward fund. 

This devastating bomb attack on Park Police Station continued to be reported throughout February, March and April - and by April 9th 1970 the reward fund had reached $38,000, with Police Chief Alfred Nelder informing the press that four full-time inspectors had been detailed to track down the responsibles.

Therefore, it really isn't surprising that the Zodiac Killer, who threatened to bomb school buses and had a wanted poster and rewards offered for his capture, decided to piggyback off this story and begin his April 20th 1970 letter with the wording "I am mildly cerous as to how much money you have on my head now.  I hope you do not think that I was the one who wiped out that blue meannie with a bomb at the cop station". By invoking the murder of Sergeant Brian McDonnell, adding a bomb diagram to his latest letter, and writing "Even though I talked about killing school children with one (a bomb), It just wouldn't doo to move in on someone else's teritory", accompanied by the attribution of SFPD=0 - it was apparent that the Zodiac Killer was prepared to move his perceived bombing campaign to another district in San Francisco. The drawing of a school bus to the left of a steep embankment mirrored exactly a location just 274 feet from the San Francisco Police Department (SFPD) of Ingleside Police Station, which closely aligned with his Mount Diablo map and Z32 code. 

THE ANSWER TO THE MOUNT DIABLO CODE

The Zodiac Killer's letter may have made a subtle reference to the uncle of Brian McDonnell, Sergeant Joseph Emmett Lacey (40), who was murdered on December 30th 1956 while socializing with a friend at Eddies' Cocktail Lounge at 502 Ellis Street, San Francisco. The two were enjoying a drink when two armed men burst into the establishment with the intention of robbing it. Sergeant Lacey, despite being off-duty at the time, drew his gun and attempted to put a stop to the robbery, but was beaten to the draw and sadly killed. The April 20th 1970 communication stated that "there is more glory in killing a cop than a cid because a cop can shoot back".

Whether this was in anyway connected to the murder of Sergeant Joseph Emmett Lacey in 1956 is unknown, but its immediacy after the reference to the killing of family member Sergeant Brian McDonnell in the letter, makes it an outside possibility. The Zodiac Killer had on many occasions showed us his ability to delve into the distant past to fashion his communications.

But after mentioning it "wouldn't do to move in on someone else's territory", why would he choose Ingleside Police Station adjacent to the Southern Freeway as his next location to "rub the officers noze in their booboos"? Despite the Zodiac Killer's ability to draw from yesteryear, almost everything contained within the many Zodiac communications were often sourced from recent newspapers. In this instance, it was imperative to look through the recent publications about the Park Police Station bombing and murder of Sergeant Brian McDonnell, to see if Ingleside Police Station got a mention regarding future security measures to combat similar attacks. Any reference towards this police station may have been the only inspiration needed by the Zodiac Killer to make this his next target, and somewhat replicate the bombing attack on February 16th 1970. As usual it didn't take much searching, because Ingleside Police Stations featured numerous times in newspaper articles about the Park Police Station bombing.        

Police Chief Alfred Nelder explored the idea of installing high wire fences and floodlights around the whole of Park and Ingleside police stations, which due to tree coverage were the most vulnerable to sneak attacks and bombings. This measure would have been circumvented had the Zodiac Killer placed his bomb on a school bus route alongside the Southern Freeway---yet would still have had the devastating consequences of murdering schoolchildren within earshot and eyeline of Ingleside Police Station for maximum impact and embarrassment. The Zodiac Killer would have achieved his goal of targetting schoolchildren and a police station under the collective banner of one single attack. 

Another San Francisco Chronicle newspaper article in February 1970 reported that the previous year San Francisco police had tried out---and rejected---steel window shutters, which could have prevented the death and injury at Park Police Station. Cecil L.Ball of Ball-Bilt Millwork said he believes the bulky, heavy interior shutters would have absorbed the shock of the Park Station bombing and would have knocked down the deadly building staples which were sprayed through the air. His company put together a set of the shutters----consisting of half-inch thick steel armor plate mounted on heavy timber---which were tried out briefly at the Ingleside Police Station.   

The Zodiac Killer long claimed he was "crackproof", but he may also have proved to be "bombproof" had he placed his photoelectric cells on the embankment bordering the Southern Freeway. A countermeasure designed to target schoolchildren and the police, and render floodlights and fencing around such places as Ingleside Police Station effectively useless. The inspiration for which may have germinated in the mind of the Zodiac Killer as he read about the callous murder of Sergeant Brian McDonnell in the newspapers---who became the focus of his April 20th 1970 letter.   

Apart from the tragic murder of Paul Stine on October 11th 1969 in Presidio Heights, the overarching weight of Zodiac communications in San Francisco in late 1969 and 1970 focused on schoolchildren, school buses and schools, whether that be by "picking off the kiddies as they come bouncing out" or blowing them to smithereens by the use of a bomb. Spearheaded by Inspectors David Toschi and William Armstrong, they meticulously searched for the infamous Zodiac Killer for many years, with David Toschi continuing his pursuit into his most turbulent year of 1978, when the Zodiac Killer resurfaced on April 24th 1978 and declared "I am back with you", while asserting that the "city pig toschi is good -- but I am smarter and better".

But why did the Zodiac Killer feel the need to reappear and write two letters on April 24th 1978 and May 2nd 1978, other than their callback to the Oscars movie ceremony, which was celebrating its 50th Academy Awards of cinematic achievement at the Dorothy Chandler Pavillion in Los Angeles on April 3rd 1978? Why did the Zodiac Killer wait at least three weeks after the awards ceremony to add such phrases as "I am waiting for a good movie about me. Who will play me" (04/24/78), "Hey-you actors-this is your lucky Break. Remember-whoever plays me has his work cut out for him" (05/02/78}, and "hold the applause" (05/02/78}?  What events happened close to April 24th 1978 that compelled the Zodiac Killer to put pen to paper, that had relevance to San Francisco, relevance to David Toschi, and relevance to schoolchildren, that occurred just prior to the mailing date of this letter? Something newsworthy related to schoolchildren who the Zodiac Killer many times threatened to target in San Francisco. By declaring "I am back with you" when writing to the San Francisco Chronicle, was the Bay Area murderer attempting to stoke up fear in the region with the possibility of more attacks in the near future?   

On April 18th 1978, six days before the "I am back with you" letter, a 15-year-old child, Ernesto Apodaca, was shot and killed at Unity Junior High School at 1950 Mission Street, San Francisco. On April 20th 1978 Police Chief Charles Gain informed the press by way of a news conference at the school district headquarters that uniformed officers would be assigned as protection to San Francisco public schools to reassure the community its schoolchildren were safeguarded. School Superintendent Robert Alioto, who had arrived at the school approximately 30 minutes before the body had been removed from the playground, stated "I don't know how we can control something like this". Robert Alioto was unsure how he was going to manage this situation moving forward, but the Zodiac Killer had little self doubt in his forthcoming letter only four days away, when he wrote "I am now in control of all things".

We absolutely know that the Zodiac Killer was inspired by recent newspaper articles and breaking news----and this breaking story about a school shooting investigated by Inspector David Toschi just days before the arrival of the April 24th 1978 letter, naming him in the correspondence and announcing "I am back" in San Francisco----has to be a reasonable candidate that shattered the four year hiatus of the Zodiac Killer.   

A 17-year-old man, not connected to the school, gave himself up to police shortly after the murder, confessed to the crime, and was placed in the custody of the California Youth Authority. The mother of Ernesto Apodaca, shattered by the senseless murder, described her son as "a nice kid with a good attendance record". Almost two years after the murder, Lucia Apocada stated that she intended to sue the Unified School District for $1 million, claiming the school should have prevented outsiders from accessing school property. I suppose the question that has to be asked of April 24th 1978, is whether a recent school shooting in San Francisco, which David Toschi was integral to investigating, awoke the Zodiac Killer from his slumber to inspire him to drive fear into the community once again, by addressing the prominent newspaper in San Francisco with the immortal words "I am back with you".      

On July 10th 2024 I wrote an article about Heidi Hoffman (16) and Lenny Parsons (19) who had parked their vehicle at the end of Saddle Road by Heavenly Valley in South Lake Tahoe on December 13th 1969, when a man approached the young couple at approximately 9:45 pm carrying a flashlight, before shooting them with a 12-guage shotgun. Heidi Hoffman was struck by 40 pellets, with Lenny Parsons hit 7 times.

This came one month after the Sacramento Bee reported multiple threats by the "Zodiac Killer" on school buses at Incline Village over the previous few weeks, culminating on November 23rd 1969. There remained a faint chance this may have been the Bay Area murderer, who was known to target couples armed with a flashlight. On the other hand, it was considered they may have been targetted by known double murderer, Joseph Stephen Holt, who lived at 1390 Keller Road when he murdered Brynn Rainey eight years later in 1977. This address was less than a mile from the double shooting. 

However, after further digging, I discovered another newspaper from the Sacramento Bee on December 17th 1969, which describes the confession of Gerald Paul Smith (17), a marine from Camp Pendleton, who admitted to police he was responsible for firing at the couple with a shotgun in a case of blind panic. In an extremely suspect account of events, he claimed himself and a 15-year old companion were looking for a Christmas tree, when they mistook footsteps in the distance for an approaching bear or bobcat and fired indiscriminately to protect themselves. What a load of baloney. 

Anyway, just recently I have added some additional material to the article "The Reason Why the Zodiac Killer Wrote the Exorcist Letter on January 29th 1974", explaining its links to the April 24th 1978 and May 2nd 1978 letters, including some newspaper cuttings from 1972 showing why the Zodiac Killer wrote "Pat Boone is an obscenity to the rest of the world". The Bay Area murder had a long memory, which may have extended to the use of library microfiche to compose his communications. The above article and its follow up "A Pawn in a Game of Death", corroborates the case that the April 24th 1978 letter was mailed by the Zodiac.   

On April 15th 1971 the San Jose sheriff's office received an unsigned letter invoking the pseudonym of Zodiac and speaking of "another victim" and the "next victim". The Zodiac Killer letters - by and large - were simply a product of the newspapers he read - and this communication was no different. From April 12th 1971 to April 15th 1971, the newspapers were rampantly speculating on whether the Zodiac Killer was responsible for the April 11th 1971 murder of Kathy Bilek (18), who was brutally stabbed in the Villa Montalvo woods in Saratoga. They were repeating the narrative of the possible involvement of the Zodiac Killer by describing Kathy Bilek as a potential "another victim" of the Bay Area murderer. Therefore, it really isn't surprising that the Zodiac Killer (or somebody pretending to be him) would latch onto this phrase and use it to garnish the letter. The implication being that the author was insinuating their connection to the murder. 

This was repeated in the use of the phrase "next victim", where the author harnessed wording from the ongoing advertising of the "The Zodiac Killer" movie, directed by Tom Hanson and released in San Francisco on April 7th 1971. The advertisements ran all over the Bay Area (and beyond) with a callback to the 1966 "Confession" letter, which stated "I lay awake nights, thinking about my next victim". But strangely, the author of the April 15th 1971 letter pre-empted the August 1st 1973 "Albany" letter, both of which suggested they would claim a "next victim" from a medical facility. We know that the "Albany" letter referred to a female target from the Albany Medical Center on August 10th 1973 at 5;00 pm during shift change, but who was the "next victim" in the April 15th 1971 letter?         

We may likely never know whether the Zodiac Killer responded to the "Dirty Harry" movie, released in San Francisco on December 21st 1971, because communications from the killer (and possible hoaxers) were at this juncture routinely withheld from the newspapers. According to document examiner Robert Prouty in 1987, he claimed there were currently at least 15 "hoax" Zodiac communications a year, which of course, nobody can confidently assert without verifying who mailed them through DNA or fingerprints. The Zodiac Killer communication count exceeds 30, but could be as many as 100 or more. 

In the April 15th 1971 letter, the author used the wording "girl works in hospital" and could be the "next victim", so the logical approach would be to collectively look at the recently released Zodiac Killer film by Tom Hanson, the movie poster, and its accompanying advertisement in the newspapers. The movie poster and advertisements carried the phrase "next victim" - therefore we should watch the movie and see whether or not it features a girl working in a hospital. You know the answer already - of course it does. 

​Towards the end of the film, "Jerry" (the Zodiac Killer) played by Hal Reed, enters a hospital to visit his father and briefly interacts with a nurse in the corridor and exchanges pleasantries. After getting upset when his father fails to reply to him, Jerry proceeds to murder two patients from the hospital. Eight days after the release of "The Zodiac Killer" movie in San Francisco, with "next victim" featuring on its movie poster and newspaper advertisements, somebody wrote a letter to the San Jose sheriff's office hinting at the murder of Kathy Bilek and suggesting that the "next victim" could be the "girl who works in the hospital". The actress who played the nurse in the film was Melissa Mosley. Without seeing the entirety of the letter, it's impossible to tell whether the author was threatening the actress in the movie to achieve increased gravitas, or was drawing inspiration from the film and generalizing about murdering a nurse, as he may have done just over two years later on August 1st 1973.

​What we do know, is that about two weeks later, the real Zodiac Killer mailed a 148 character cipher & letter implying he was the murderer of Kathy Bilek (18), Kathie Snoozy (15) and Debra Furlong (14) in Santa Clara County - and followed this up by mailing the "Monticello" card on July 13th 1971, again insinuating his involvement in the three murders. These two communications somewhat mimicked the April 15th 1971 letter, which had used the phrase "another victim" (of the Zodiac Killer) from the newspapers in relation to the recent murder of Kathy Bilek. This means that three communications were mailed consecutively in 1971 - and all hinted at the murder of Kathy Bilek. Two were definitely from the Zodiac Killer, but what about the third, mailed to law enforcement in San Jose on April 15th 1971?