I interviewed a comedian years ago who lamented to me that a TV comedy she had come up with about an eating disorder was unfilmable. However loveable the protagonist and acute the observations, you simply couldn’t put the grim reality of certain key details – bags of vomit were mentioned – on the screen . I imagine a similar hesitancy delayed Jeffrey Dahmer’s journey to TV drama. The stuff of his story – dissected roadkill, homemade lobotomies, bodies dissolving in vats – all sounds too gross for prime time. But the public are obsessed with serial killers and years of...