Serial has been dissected from almost every conceivable angle, down to the mispronunciation of the sponsor’s name, but as Sarah closes the case on Adnan, Jay, and the rest of the Woodlawn characters, one mystery remains undiscussed — who designed the the black, beige, and red “S” that has popped up on millions of iPhone screens over the last three months?

Thankfully, that mystery is easier to solve than the horrific murder at the center of Serial. The logo was crafted by Matt Dorfman, an award-winning designer who was worked for NPR, Vanity Fair, and Time, and is currently the art director of the New York Times’ Op/Ed page.

“My process in working with the Serial team played out in an eerily similar way as one of the show’s episodes,” writes Dorfman. “We talked, we kicked some questions around, we extrapolated some ideas based upon those questions and chased down a mark without any preconceived impression of where it should land.”

Dorfman started working with Serial’s production manager,Emily Condon, back in February 2014. “All I was told about the story in the brief was that it involved a murder in Baltimore in 2000 that involved high school kids,” says Dorfman. “To the producers’ credit, the specifics of the story didn’t factor into the logo at all —families’ pain shouldn’t be branded.”

After experimenting with a variety of concepts, Dorfman focused his creative energies creating a graphic representation of the show’s distinctive format and decided each letter should occupy its own block to suggest the weekly episodic reveal. “Our principal focus in establishing the show’s identity became landing on a typographic statement that would suggest the brick-by-brick nature of the show and hint at what a mid-century radio serial might look like in the age of the internet.”