“Do you know where cyanide can be found?”

That was how the letter began. No fingerprints on it, no hair follicles. It was typewriter-written, ink slightly blotchy - but that was to be expected for old technology. The important thing was that it hadn’t been typed on a computer, or printed. It had shown up on the desk of the chief of police this morning, already pressed neatly into a clear plastic evidence bag. Strange.

“It’s easy to procure, really. Startlingly so. Just crush up enough stonefruit pits, or apple seeds - even almonds, though those are meant to be chewed. I was certainly surprised, and that’s one of my big motivators. Of course for the sake of covering all of my bases I won’t tell you from which source I derived mine.

“As I’m sure you’ve guessed, I’m confessing to murder. Serial, in fact. Lovely title - I’ll confess to something else, and that’s that I had a little celebration once I earned it officially. And no, this isn’t an elaborate prank. A real serial murderer, in 2020! Hard to do, I’d think.

“Back on the topic of cyanide, that’s what I used to commit my murders. Without looking too carefully at the obituaries in the paper, I’d assume most or all of my victims have been marked down as accidental deaths. Carbon monoxide poisoning, perhaps? Cyanide, you see, has a very short half-life - within a number of hours, it’s impossible to detect in a postmortem evaluation. Fascinating, isn’t it?

“The victims don’t follow a specific profile. Of course not! That’s idiocy, in my opinion. No, they’re - rather, they were - just random people who happened to, I don’t know, turn their back on a hot drink in a public space, or something of the sort. And of course their locations share only the fact that they’re busy places. My only consistent habit is the use of that one specific poison. And I rarely stay to watch them die, as it’s a quick-acting substance and I’d rather distance myself. You know how it is.

“As to motivation: I simply find it entertaining to snuff out lives. I think each life contains the universe, or one unique view of it. Ending a universe! Now that’s real power! At least, if you ask me.

“Anyway, all this is to say that I’m here, I’m quite devoid of remorse, and I will be continuing to conduct my little philosophical experiments. Catch me if you can, though I doubt you’ll be able to. Sincerely (and I do mean that),

“Guess who?”

It was an interesting letter, to say the very least. More interesting were the circumstances of its arrival on the desk this morning. The thing was - it had simply been carried in. That was all. A casual delivery, totally immemorable.

After all, who among the city's self-proclaimed finest would ever suspect one of their own?