I would want to take the astrological analysis just one step further.

We have noted how the sign matrix presents the sign locations for just the first five classical astrological bodies—the two luminaries (Sun and Moon) and the first three planets (Mercury, Venus and Mars). We have also seen how, out of the forty entries, only one has one of these five bodies arrive in a sign other than one from the grouping of the domiciles of these five alone. I have suggested that this, of itself, is a specific feature that the compositor was intending to emphasise, and it would be plausible to propose also that it carries relevance in promoting some degree of favourable conditions on the murder dates. Equally, however, we can also notice that there is an unusual spread of instances where any three of the five bodies sit in the same sign, or in adjacent signs to some other such pairing. Again, we might suggest that this is being considered a conducive alignment element also.

So, what when we get to the final incomplete row? Well, here we find a unique and potentially very auspicious arrangement of the planets, with all of Mercury, Venus and Mars residing precisely in one of their own domiciles. Further, if we do the calculations to determine on what earliest future date the arrangement of the Moon and planets in the final row may occur, we find that this would be on one of either the 21st or 22nd of June 1990.

Now, these dates are important for another reason, as they span the summer solstice, the precise moment when the Sun transitions from Gemini into Cancer. This then means that for a proposed date just prior to the moment of Solstice, we have the two luminaries together with Mercury all in Gemini, along with all three planets placed in their domiciles and, astrologically, most potent.

I would then offer that there is good evidence in this to suggest that the letter was mailed by someone studying patterns from a primarily astrological point of view, to then construct a method of predicting when any further murder might be likely to take place. It does not appear to be the kind of analysis the killer himself would produce.

This would seem to accord with other missives received by authorities around the time claiming when the next attack will come.

Since we are on the subject, I should also mention a couple of alternative interpretations of “ME 72 MAY”, even though I personally do not find them particularly convincing. I am only mentioning them for completeness.

According to some researchers, “ME 72” could refer to Miriam Ana Escobar, who was murdered in 1972. The obvious problem is that her murder took place in March, not May, so “MAY” does not fit very well with that interpretation.

Another interpretation that has been suggested to me is “ME” = “Missing Event”: in other words, the author may have identified a configuration in May 1972 in which the Monster was expected to strike, but the event never actually occurred. I do not particularly share this interpretation, but I mention it because it could fit with your idea that the author of the letter was using astrology to try to identify a possible future event after 1988.

In this respect, there is another interesting detail regarding the possible interpretation of the number triplets.

In the last complete row, the one associated with 1985, we find the triplet:

11 12 06

If we read this as a geographical coordinate in degrees, minutes and seconds, 11°12′06″ E falls practically on the longitude of the Scopeti clearing, where the final double murder took place. Publicly available coordinates place the clearing at approximately 11°12′07″–11°12′08″ E, so the difference is only about 1–2 arcseconds, corresponding to just a few tens of metres.

I do not know whether this is intentional or simply a coincidence, but I think it is worth keeping in mind, especially because the card enclosed with the letter already contains what is effectively a map of the murders, constructed using the lines of a palm.

It struck me, when scanning what was being visually presented during the 1987 Telefono Giallo TV show, how the map presented there—using dots for the murder locations together with connecting lines—may have been suggestive to some viewer at the time of a palmistry interpretation.

And what do you think about the possibility that the Monster’s author deliberately constructed some kind of puzzle letter, using geographical coordinates as part of the message?

Just to check, @lendor-77, do you mean through reading the first three numbers in the left column as geographic longitudes, as you did with the last for the Scopetti clearing? I can’t see that there is any way to force any of the values into a geographic latitude, can you?

I’ll be honest: I have found, in other anonymous letters as well, some indications of coordinates being used to point to a specific location. So I cannot rule out the possibility that my interpretation has been influenced by the fact that the final triplet seems to correspond to the coordinates of Scopeti.

Starting from this possibility, I tried to interpret the left-hand side of the letter by looking at the delta between the actual coordinates of the murder sites and the “fictitious” coordinates derived from the values given in the letter. The idea was to see whether these differences could generate a meaningful sequence or provide some kind of key to the decoding. Unfortunately, at least in the attempts I made, this approach did not produce any useful results, although of course I cannot rule out the possibility that I applied the method incorrectly.

The same line of reasoning also led me to question the meaning of the abbreviation “DX”. Besides the more immediate interpretation as “right” (destra in Italian), I considered whether it might instead be read as ΔX, meaning “delta X”, and therefore as an indication of a difference in the X-coordinate. In a Cartesian or geographical representation, the X-axis can be associated with longitude. From this perspective, “ΔX” could therefore be suggesting the calculation of a difference between longitude values.

This might help us consider your idea objectively:

Posted by: @lendor-77

↑

The same line of reasoning also led me to question the meaning of the abbreviation “DX”. Besides the more immediate interpretation as “right” (destra in Italian), I considered whether it might instead be read as ΔX, meaning “delta X”, and therefore as an indication of a difference in the X-coordinate. In a Cartesian or geographical representation, the X-axis can be associated with longitude. From this perspective, “ΔX” could therefore be suggesting the calculation of a difference between longitude values.

This is certainly an interpretation that I had noticed, but I have not yet fully pursued that possibility. I will do so next.

It is also worth considering whether the ‘dx’ might relate to a delta in the Right Ascensions themselves, considered as such. It is of particular note that if we convert the RA for 1984 (08h 34m 59s) to its date/time equivalent using the plausible B1950.0 epoch convention then we get precisely 29 July 1984, 21:45 CEST. So this stands out as having a zero ‘delta’. All the others are out by some margin and, as of yet, I have been unable to account for how these differences are arising, by what method or according to what pattern. That the one hits the precise reported time of the heard gunshots, however, certainly appears as remarkable.

Using the same B1950 apparent-Sun framework and the representative event times, with:

ΔRA = artefact RA − RA at event time
Δt = time implied by artefact RA − event time

we get:

See, I think this is where things become interesting again. What I would try is converting all the deltas into letters using an A=0 Caesar-type system, then running through all possible shifts to see whether anything recognizable emerges. I suspect it may ultimately be a dead end, though.

I tried something similar with the geographical coordinates as well: adding them, subtracting them, combining them in pairs, grouping the values in different ways, and so on. So far, nothing meaningful has come out of it.

A few days ago I was thinking again about what you said regarding the Z32: that, in trying to solve it, we should not really be using Google Maps, but rather a ruler, a set square, and the material that Zodiac himself could realistically have had available at the time.

I think the same principle may apply here. Perhaps we should be careful not to go too far beyond the tools and reference material that the author himself could have used.

What I mean is this: once we start using modern astronomical software, highly precise online ephemerides, or the exact modern coordinates of the murder sites and then try to combine them with the values given in the letter, we introduce a methodological problem. We may be working with data that are more precise, or simply different, from the data available to the author.

For example, what map was he using to locate the murder sites? He may have plotted them slightly differently from the exact coordinates we use today. And what manual, tables, or ephemerides was he using to calculate the Right Ascensions? If his source was different from the one we are now using online, or if it employed a different epoch, convention, level of precision, or rounding method, then we may never reproduce his values exactly.

I think this is one of the main difficulties with this kind of approach. Even if there really is a precise method behind these numbers, we may fail to reconstruct it simply because we are starting from different tools and reference data from those available to the author at the time.

Don’t you think?

On your specific question, regarding the first column interpreted as longitudes, the only thing that immediately jumps out is that the RA for 1983, interpreted as a longitude, is the only one other than 1985 that falls within the full range of longitudes for the murder sites. It does not, however, meaningfully approach the longitude of the associated site, but it does stand out for another reason in that it’s RA is highlighted through underlining.

Posted by: @lendor-77

↑

I think this is one of the main difficulties with this kind of approach. Even if there really is a precise method behind these numbers, we may fail to reconstruct it simply because we are starting from different tools and reference data from those available to the author at the time.

Don’t you think?

This is actually a barrier I’ve been trying to break through using whatever methods I can reasonably think of. I have consulted contemporary ephemerides to discover that the calculations can be avoided and replaced with simple table reading and subsequent interpolation. I have tested the impact of using different epochs for the precise calculation methods. I have even tried replacing modern tables with archaic models, such as the Prutenic tables based on the Copernican solar model. Yet still, nothing is replicating the specific deltas that we are seeing in the left hand column. I’ve pursued the same, through introducing plausible sources of error and of rounding, but again nothing.

Shift    | 1968     | 1974     | 81 Jun    | 81 Oct    | 1982     | 1983     | 1984     | 1985
------------------------------------------------------------------------------------------------
Original | 10 01 56 | 11 34 27 | 05 01 53  | 14 05 34  | 05 51 21 | 11 08 02 | 08 34 59 | 11 12 06
A=0 / 0  | KBE      | LIB      | FBB       | OFI       | FZV      | LIC      | IIH      | LMG
1        | LCF      | MJC      | GCC       | PGJ       | GAW      | MJD      | JJI      | MNH
2        | MDG      | NKD      | HDD       | QHK       | HBX      | NKE      | KKJ      | NOI
3        | NEH      | OLE      | IEE       | RIL       | ICY      | OLF      | LLK      | OPJ
4        | OFI      | PMF      | JFF       | SJM       | JDZ      | PMG      | MML      | PQK
5        | PGJ      | QNG      | KGG       | TKN       | KEA      | QNH      | NNM      | QRL
6        | QHK      | ROH      | LHH       | ULO       | LFB      | ROI      | OON      | RSM
7        | RIL      | SPI      | MII       | VMP       | MGC      | SPJ      | PPO      | STN
8        | SJM      | TQJ      | NJJ       | WNQ       | NHD      | TQK      | QQP      | TUO
9        | TKN      | URK      | OKK       | XOR       | OIE      | URL      | RRQ      | UVP
10       | ULO      | VSL      | PLL       | YPS       | PJF      | VSM      | SSR      | VWQ
11       | VMP      | WTM      | QMM       | ZQT       | QKG      | WTN      | TTS      | WXR
12       | WNQ      | XUN      | RNN       | ARU       | RLH      | XUO      | UUT      | XYS
13       | XOR      | YVO      | SOO       | BSV       | SMI      | YVP      | VVU      | YZT
14       | YPS      | ZWP      | TPP       | CTW       | TNJ      | ZWQ      | WWV      | ZAU
15       | ZQT      | AXQ      | UQQ       | DUX       | UOK      | AXR      | XXW      | ABV
16       | ARU      | BYR      | VRR       | EVY       | VPL      | BYS      | YYX      | BCW
17       | BSV      | CZS      | WSS       | FWZ       | WQM      | CZT      | ZZY      | CDX
18       | CTW      | DAT      | XTT       | GXA       | XRN      | DAU      | AAZ      | DEY
19       | DUX      | EBU      | YUU       | HYB       | YSO      | EBV      | BBA      | EFZ
20       | EVY      | FCV      | ZVV       | IZC       | ZTP      | FCW      | CCB      | FGA
21       | FWZ      | GDW      | AWW       | JAD       | AUQ      | GDX      | DDC      | GHB
22       | GXA      | HEX      | BXX       | KBE       | BVR      | HEY      | EED      | HIC
23       | HYB      | IFY      | CYY       | LCF       | CWS      | IFZ      | FFE      | IJD
24       | IZC      | JGZ      | DZZ       | MDG       | DXT      | JGA      | GGF      | JKE
25       | JAD      | KHA      | EAA       | NEH       | EYU      | KHB      | HHG      | KLF

And just as an exercise, here is the corresponding table that would be generated, without any deltas, for the four canonical Zodiac attacks: