Chasing the Radians: the Unit Circle Message Board: Theories: Chasing the Radians: the Unit Circle

By Peterh (Peterh) ( - on Wednesday, January 10, 2001 - 10:59 am:

Over in the Kazinsky thread I wrote:

"I would begin by placing a circle of one inch radius centered on Mt Diablo, aligning the X (vertical) axis with magnetic north (as of 1970), tracing the known BRS/SF radian and all the (approximate) radians suggested by the marked symbol on the Nov 9, 69 letter. Then look at all of the intersections of the rays of the radians and the circle, and see if any of these points are on rural roads. If so, I would check out these spots to see if they are consistent with the bomb diagrams that show any topographic detail. (I believe there is at least one that calls for a steep embankment close to the road, apparently so that a photoelectric device could be leveled with the height of the school bus). Of course, none of this is likely to lead directly to an ID, but it _could_ lead to cracking the Mt. Diablo cipher, which _could_ lead to crackng the "my name is" cipher . . . "

OK, I did this, as best I could, by gleaning the scale from Tom's repro of the Phillips 66 map. I read the scale legend on the map as "One inch equals approximately 10 miles", but I cannot read it clearly, so I would appreciate confirmation/correction from anyone with a clear copy. SO. I place a ten mile radius circle on Mt Diablo, and align the O axis with magnetic north. (About 17 degrees east of true north at that point, but again, anyone have better information?) Bingo: the 8:00 position lines right up with the SF ray of the Penn radian, and the 10:00 position is the BRS ray. 9:00 passes about half way between Lafayette and Pleasant Hill. Points of intersection between the radian rays and the ten-mile circle turn up two possible locations. The first is on St Mary's Road, in or near Moraga, 500 to 1500 feet north of Rheem Bl, near St Mary's College. The road here runs north/south (one of the requisites for at least one of the bus bomb diagrams). Clearly a rural area. See a good shot of the St. Mary's Campus and surrounding area at: Second candidate is about half way between Lafayette and Pleasant Hill, on Taylor Bl. (or possibly Reilez Valley Road a few hundred feet west) near Withers Avenue and Brookwood Park. Info at the Pleasant Hills website (cached at indicates at least suburban and possibly rural setting here as well. Other points yielded by this scheme include one near the intersection of I-680 and Cal Rt 4 near Concord, one in Port Chicago near rt 4 and one on an island in the Sacramento River near Pittsburg. On paper, these don't look like good candidates to me, so I didn't run them to ground on detailed maps.
SO. Based on the foregoing, I proffer as my prime suspect location for Z's bus bomb: the west side of Moraga Road, 500 to 1500 feet north of Rheem Boulevard, Moraga, California.
Anyone in that area want to check it out?


By Hurley (Hurley) ( - on Friday, January 12, 2001 - 04:59 pm:

Good job PeterH.

By Peterh (Peterh) ( - on Saturday, January 13, 2001 - 12:09 pm:

Thanks. But Oops, I meant "west side of St. Mary's Road", not "Moraga Road". Hmmm, St. Mary's. Diametrically opposed to "Diablo", no?


By Peterh (Peterh) ( on Wednesday, January 17, 2001 - 04:48 pm:

I may be talking to myself here, but here's a new item. I have examined the USGS maps of my bomb site (scale 1;24,000, pretty detailed) and determined the following. The stretch of St. Mary's Road in question has three interesting topographic characteristics. First, there is a small stream close to the west side of the roadbed, consistent with the ditches shown in Z's diagrams. Second, it fits _both_ diagrams with respect to the embankments on the side(s) of the road. On the southern section of this stretch, there are steep hills close to both sides of the road, to accomodate the elevated light source and reflector, as shown in the Nov 9. '69 diagram.
A few hundred feet to the north of that section, the hill on the east side opens up into a long, shallow valley, giving a clear view of the early morning sun from the steep and high hill on the west side, precisely as shown in the April 19, 1970 diagram. Finally, there is the lament in the April 19 letter that the bomb was "swamped out" in a recent rain. I can just picture the little stream along St mary's road rising and swamping out Z's bomb buried along its banks.
Now, anyone want to go visit Moraga and see if that was a school bus route in 1970. I got a buck or three says it was . . .


By Sandy (Sandy) ( - on Thursday, January 18, 2001 - 11:04 am:

I will check it out! I am pretty sure it was a bus RT. Also one of the suspected Z victims Cosette Ellison was from Moraga, 3/3/70 ,Elaine Davis on 12/1/69 was from Walnut Creek a few miles from there.I was from that area of Contra Costa,Ca. Before that time, and shortly after.

By Peterh (Peterh) ( on Thursday, January 18, 2001 - 04:54 pm:

Two victims of someone from that area? I wasn't aware of either of these, but note that Z says in the April 19 letter with the second bomb diagram that it just wouldn't do to move in on someone elses territory.

Let me know what you find in Moraga.


By Peterh (Peterh) ( on Thursday, January 18, 2001 - 05:16 pm:

Sandy: when you go out to St. Mary's Road, if you could please take along a camera, even a disposable would be ok, but if you have a good one, so much the better. Look from about the St. Mary's college campus northward, especially the stretch for half a mile or so north from Rheems Bl. Look for places where the road runs north-south, there are hills at least as high as a bus on both sides of the road, as well as where there is a hill only on the west side. If you could go about 8:00 in the morning or at least estimate the height of the sun at that hour, so much the better.
Good luck


By Jud Johnston (Jud) ( on Wednesday, March 21, 2001 - 08:12 pm:

Well, did we find anything? Nice sleuthing on your part, Peterh, but I keep wondering what Z is going to tell the cop who happens to drive by while Z is up there with his shovel, wire leads, batteries, reflector tubes, etc, at midnight thirty. "Aw, nothing much, just digging in a bus bomb."

By Douglas Oswell (Dowland) ( - on Wednesday, March 21, 2001 - 10:43 pm:

Just the process of aligning those cardboard tubes would require some fairly sophisticated instrumentation and the light of day.

By Howard Davis (Howard) ( - on Thursday, March 22, 2001 - 03:04 am:

Sandy-Dets. in Walnut CREEK told me they found Cosette Ellison at the base of MT. Diablo (Devil's MT.)using heat detection instrumentation.
There was a pickup seen near her home that was suspected as being the perp's vehicle .

Elaine Davis was abducted off of her porch (she went out to sneak a smoke-in this case it shows smoking IS bad for you!)and she has never been found. The PD did find some articles that belonged to her near Santa Cruz (I know it was Crabtree-he did live close by!)off of the freeway.There is an canal/water running through her back yard. The dets.told me they already noted that as a Z trait-the water element!Elaine had been shopping with her mother at the Concord Mall that day and it was soon after she came home the abduction took place. I suspect she was followed from the Mall.The killer's ruse could have been do you have a spare cig'and/or light?

The Walnut Creek dets. are real professionals and they were very respectful.They even gave me details of the crimes with the proviso they not be revealed and this I have done. We need more WC dets. and Baker types in the system -it would work a lot better as to efficient PD methodologies and solving crimes!

By William Baker (Bill_Baker) ( - on Thursday, March 22, 2001 - 11:31 am:

Howard, what was the date that Elaine Davis went missing?

By Ed N (Ed_N) ( - on Thursday, March 22, 2001 - 04:36 pm:

Bill: according to Graysmith, Elaine Davis went missing on 12-1-1969, and has never been found (Zodiac, pp. 128, 309).

By William Baker (Bill_Baker) ( - on Thursday, March 22, 2001 - 10:53 pm:

Thanks, Ed. I was too lazy to look it up. I had our 1969 Jane Doe homicide in mind, but she was found in early August '69.