NBC wanted The Walking Dead, but without the zombies

This is why I hardly ever watch network television.

From Variety:

Before the show was picked up by AMC for domestic and Fox for international, its creator Frank Darabont presented the first version of the script to NBC, with whom he had an overall deal. According to [Gale Anne Hurd, executive producer on The Walking Dead] their response was, Do there have to be zombies [in it]. NBC then asked Darabont if the show could be a procedural in which the two main protagonists would solve a zombie crime of the week, she said.