The fixation on Geordie Jack was the main reason why it took so long to catch Sutcliffe. The man who carried out that hoax had a lot to answer for - he could have owned up at any time when he saw what transpired, but didn’t. He derailed the whole investigation. I was interviewed twice just because I lived in the area where the murders happened and came from the North East, and my male relatives were checked out - their backgrounds, when they’d visited, etc.
That huge mistake aside, it’s easy to criticise the whole police force as being “stupid”, without taking into account the fact that this all happened before computers, before DNA, before gathering information became an easy click of a button. Sutcliffe wasn’t suspected even by his nearest and dearest, living as he did a quiet life with his teacher wife. I knew a relative of his who was as shocked as anyone by the arrest. They’d all seen that infamous photo fit - it was in every newspaper. Yes, it looked like Sutcliffe, it also looked like many other young men at the time with the trendy 70s sideboards and moustache. My DH was ribbed for his resemblance to it, so were several friends. There was no pattern as regards age or ethnicity of the victims, and the murders took place irregularly over a wide area. Cross-checking of the many thousands of interviews and leads was down to sorting through index cards. Police station floors had to be reinforced to deal with the weight of the files. Yes, Sutcliffe was questioned several times. So were many others, including my brother in law, driving through the red light district near where he worked.
I read an interview with the series writer, saying what huge respect he had for the majority of hard-working officers on the case, and the long, gruelling hours they put in trying to catch this man, often to the detriment of their home lives. Hindsight, of course, is the best detective of all.