Is Silence of the Lambs a Sequel?

Bull: Is Silence of the Lambs a sequel? No. There's a film that precedes it in which the character appears previous. I don't think anyone has ever referred to Silence of the lambs as a sequel. It really doesn't... I mean, it's a serial killer movie. So how do you appraise serial killer movies? All your slasher guys are serial killers, but it's a detective movie. It's a psychological novel.