By process of elimination alone it seems doubtful that that image could be of anything other than a small pencel flashlight. How many other things the size of a pencil are even made in keyring form? It is even shaped closer to a pencil than a pen in many respects. Having said that I think it’s likely the light described by Z would have been a small light with a "pencil beam", because something this small would surely be too low in output, unless it was really well made.

My thought would be, how common was something like this before the advent of high output LED lights? It would seem to me that small pencil lights with enough output to be useful would have been rare a few decades ago.

These lights are everywhere now, but if they were more uncommon it might mean less manufacturers and therefore it might be easier to track down what this object is if it is indeed a light.

The thing about the one in the image and the penlight interpretation I have is how it would be powered? AAA batteries might not fit the original Eureka image one but I just have nothing to gauge scale with. Keys could be any size.

I must admit it’s hard to tell the scale, but it does look like an awfully small example. I still can’t think what else it could be. Most of these would be powered by a AAAA battery. Streamlight made one that was as slim as this, but full length.

I think the chain is the best thing to estimate scale from as the keys could be larger than they appear. I’m going to play around with the scale and see what I can determine.

This isn’t exactly most precise method, but I’m pretty good at eyeballing stuff. I’d say the ball chain has to be 2-3mm conservatively. I’ve never seen a key chain with a ball chain finer than 2mm, which is still a little on the fine size. If I scale the image till the ball chain is at about 2.1mm I end up with a key that lines up with an average sample of every key of a similar type I could find around the house. This makes the diameter of the object that looks like a pen/pencil around 9mm, which is just enough to fit a 7.8mm AAAA battery.

The thing I don’t like is the hexagon shape, it means there’s less room for a battery to fit and if two sections come apart or unscrew you would need an inner sort of flange, which would need to be a smaller diameter again. Also I see no evidence of the object having two section that come apart.

So it’s a tricky one, but without an alternative object, there are only so many things you generally find on a keychain… well actually that’s not true, tourism will make a keychain out of damn near anything. But still it has to be some functional item, or device I think.

It’s probably a magnet just like this one.

Way to ruin the mystique. Actually I realise now, to my great embarrassment, that I’ve already seen this image a long time ago on another thread. We need to sticky this somewhere before I start anymore rumors

Anyway, my tremendous overconfidence aside, this did get me googling about old pen lights and it seems they were very common back in the day.

As I ponder the Zodiac’s choice of words, "small pencel", it does bring to mind, either a slightly larger light with a pencil beam, or a very small pen light, small enough to be described as a pencil.

What I really want to know is, how bright is a small pen light back in the day?

If we assume there is any truth to the claim and we assume it was a fairly small example of such a light, then it seems it would have to be well made. And this might be a leap, but to my mind there is a more limited number of brands that could make a high enough quality pencil sized pen light for shooting, maybe something like Kel-Lite.

It seems to me consumer grade examples wouldn’t put out enough light and if anyone was making a pencil sized light with enough output for shooting, I would speculate it might be police, or military grade. But that’s a long bow to draw I admit.

Yeah there have been a few of these suggested.

Which look good but would be better if we find them in the contemporary – 1990 or before.

The technology is pretty much the same, pre or post 1990. These have been around for a long time.

Not sure if this is the right place to bring this up, and it likely doesn’t mean anything anyway, but one thing that stood out was the red part of the line “Ask the Vallejo cop about my electric gun sight which I used to start my collecting of slaves“.

Could it be that this was a slip of the truth, being one of the early letters where he is being more factual (type of ammo, etc.) with his information, and that those victims were indeed his first? If Zodiac had killed before, wouldn’t it make more sense to say something like “which I used to kill those kids”?

Of course, later on in the The LA Times letter he takes credit for Riverside and insinuates more murders that haven’t been found, but by that point he has elaborated his persona, is really enjoying the fearmongering, and could just be taking credit.

Then again, maybe he had killed before and this was just the first time he had started considering his murders as the collecting of slaves, or maybe he was just saying that he started then to confuse matters.

Oh dear, I seem to have ended up right back where I started (which is how I feel about so much of this case!).

Anyway, I’m not mentioning this because I am against the Riverside connection or earlier possible murders being the work of Zodiac, it just struck me as a somewhat interesting turn of phrase.