I agree. Tunnel vision seems to be the most common factor in false convictions. Outside of the ego involved it doesn't help that there is outside pressure exerted on them to clear their case load and solve cases so that the state can have wins for elections, PR, etc.Most attorneys other than the prosecutorial bar share your misgivings. In altogether too many police departments, and even some prosecutors', there is a "the end justifies the means" attitude. I've had close friends who were cops. In the majority of cases, the majority of them believe in their intuition. IOW, they believe that they know almost immediately "who dunnit." Then, it becomes a very short step to make the evidence fit the preconceived notion of guilt. They are, after all, just human...
The Reid technique of interrogation has added to that problem in that they're trained to zero in on "tells" for lack of a better term that don't always work when dealing with people with varying degrees of social anxiety and/or lower IQ's/age.
Other countries have instituted systems that use other interrogation techniques and policies leaning towards finding the truth above a court victory. I'm hoping that we're starting to see the wheels turning on the idea that we truly need reform based on the number of cases that are coming into the public eye with the rise of more venues for documentaries, podcasts, online investigations and so on.