Hugo Gernsback's "The Killing Flash" (flash fiction, science fiction, free): An ingenious murder weapon backfires
Fact sheet.First published: Science Wonder Stories, November 1929.
Download full text (from PulpGen).
First science fiction story at flash fiction length (even if we won't usually call a 1400 word story "flash fiction" today), according to editor's note attached to story. That alone should make it important. It also happens to be a good story.
Story summary.John Bernard, the narrator, is going to kill Henry Lindenfeld who has "eloped with" John's fiancée. Long distance, & with an ingenious murder weapon.
Idea is this: "I will gradually assemble my high-tension apparatus, a 5-kilowatt generator, a 350,000-volt step-up transformer, condensers, and various other electrical paraphernalia... I will attach the output of the 350,000-volt up Lindenfeld on the telephone... when he answers me, I have but to step back from my phone and press a switch which controls the 350,000-volt high-tension current. The deadly current will leap over the telephone wire to Lindenfeld’s house. A long spark will jump between the receiver and the transmitter, and as Lindenfeld’s head is between them he will be electrocuted instantly—not, however, without first having heard my voice."
(I recall similar discharges used for murder in one of the Asimov's Foundation prequels set in Trantor - probably written by someone else. It didn't have a telephone; a pair mobile wireless bots could be made to settle near your ears, & discharge!)
There is only one problem - high tension discharges usually don't travel very far on telephone lines - they're quickly grounded. As luck would have it, the rented place John was using for his plans had "200 lbs. of high explosives stored on the floor above—no doubt set off by the high-tension discharge traveling along the joint telephone cable to the next floor"!