True, there are innocent people in jail and on death row. This is unacceptable. But I think it is proper to acknowledge that the right person is convicted by an overwhelming degree.
A few years ago in NewYork City, a man claimed to be sexually assaulted on deserted subway platforms. He claimed this about 30 different times, consequently, about 30 men were arrested.
He did this all over the city and since the precincts weren't coordinating arrests, it was not noticed that one man was putting in so many complaints.
About 25 of the 30 who were arrested plea-bargained because they were afraid of going to trial.
Luckily for them, a policeman responding to a sexual abuse complaint realized that it was the same man he had responded to once before. This led him to investigate as to whether the man was making up stories and he found all the innocent people and had them exonerated.