Yeah I was living in WMids at the time. WMSCS was disbanded late eighties as I recall. Their notorious case being the alleged pub bombers where statements were crudely changed and pocket books rigged. My point I think is:- are you suggesting that we had no justice at all before interviews were taped or that taping merely eliminated one place that could be open to abuse? Your post reads like you are suggesting the former.
The West Midlands Crime squad was a thoroughly bad lot - and a law unto themselves IIRC. It was a good day for justice when they were disbanded. IMO Portugal is about 40 years behind the UK and there are pockets of similarly corrupt policemen still around. Since Portugal became a democracy they are gradually moving away from that situation - but it will take time. IMO the days when the word of a policeman was automatically believed by courts over any member of the public - (which is how is used to be in the UK), are numbered - but they still have a long way to go. My own observation is that it has been a case of two steps forward and one step back thus far.
Prosecuting policemen like Amaral and Tavares etc for perjury and torture are examples of 2 steps forward. Prosecuting Leanora Cipriano for not being able to identify her torturers was one step back IMO.