For example, if my crazy neighbour knocked on my door, pushed their way into my home when I answered then beat me up - the only evidence of who did it would be my eyewitness testimony.
There would be incontrovertible evidence that someone had assaulted me, in the form of my bruise-covered face and body. But only eyewitness testimony as to who.
With the current justice system, that would almost certainly be enough for a jury to convict.
There are tragic miscarriages of justice from time to time, and certainly DNA evidence should be used whenever possible. But would I prefer to live in a world which rejects eyewitness testimony, where a crazy person can barge into my house and beat me up with no consequences? Or a world where I have to have CCTV in my own home? Not really to be honest.
In cases of rape, where there's usually ample forensic evidence, there need not be a complete reliance on someone's testimony.
For better or worst, we should accept that our justice system has holes and flaws, and we should do our best to avoid them. There isn’t much to help you and they might not have any suitable punishment or aid to give to the crazy person.
I'm not sure how a reasonable judge or jury would have come to any other conclusion given what little we know about this third-person retelling of a case so I don't think they "failed" him at least in the way I typically think of that word being used in these contexts.
Are these cases a relic before dna evidence?
I'm not saying everyone is innocent, but the number of people who were wrongly convicted by a lazy system that let shoddy police work and lax standards become the norm is shocking.
There's the old thought process that even if the guy wasn't guilty of this crime he's certainly guilty of others so they would be doing the world a favor by putting him away. In the end this is just self-justified racism.
I’m sorry, where is race the factor in this? You could make a weak claim for sexism from your post but there is no racism.