Watched all 3 parts of this in the past week, having missed it last year. Although I'm familiar with the case, it predates me by a few years and I wasn't aware of the length of time he was at large or the hysteria he instilled. Absolutely terrifying, but what became clear was that West Yorkshire Police were criminally incompetent throughout, seeking to paint all the women in the worst possible light, taken in by a hoax tape and missing or failing to follow up on vital evidence.
I don't tar all police with this brush, the head of Northumbria Police (home of Wearside Jack) had great misgivings on the veracity of the tape and its lack of inside information and the South Yorkshire Police in Sheffield who checked his number plate, realised it was fake, pulled him over and, having arrested him for soliciting, then went back and discovered the hammer and knife he had dropped, deserve immense credit - when asked how they'd caught him, he remarked to the press 'good old-fashioned coppering'. (I am of course aware that South Yorks would have their own date with disgrace a decade later when Hillsborough happened.) Really interesting watch though: 'The Yorkshire Ripper Files', available on BBC iPlayer if you're so inclined.