LOS ANGELES — A torrential downpour could not keep the murder-obsessed and crime-fixated young women from storming the Orpheum Theater in downtown Los Angeles early this spring.

“It’s like the best cult ever,” said a woman in her late 20s, who was wearing maroon Doc Martens boots and a fan T-shirt that read, “I’m a Karen!”

As the lights dimmed, about 2,000 rowdy fans, mostly women in their 20s and 30s, howled at a decibel suited to a Beyoncé set at Coachella. But they weren’t going gaga for a pop deity. Calling themselves Murderinos, they came to hear expletive-laden tales of serial killings and brutal homicides told by Georgia Hardstark and Karen Kilgariff, the irreverent hosts of the wildly popular true-crime comedy podcast “My Favorite Murder.”

Standing on an empty stage, save for a small table with two bottles of water, Ms. Hardstark and Ms. Kilgariff sailed through the show’s breezy formula: Come for the frank and funny retellings of their “favorite” murder (today’s topic: the Los Feliz Murder Mansion from 1959), stay for the chatty non sequiturs (day drinking and Oregon cults).