At the same time, there are lots of stories about plea bargains for horrible crimes that go unpunished. In that case, you have prosecutors who may not have a case, or they do the more convenient thing to save money, lighten their workload and increase their conviction rate with some kind of guilty plea.
And many times an innocent defendant pleads guilty to a crime he did not commit because it is the lesser evil in comparison with a likely conviction and a more serious charge.
Few years ago I was vacationing in Broward County, Florida. The newspapers were all over a new story that had just gotten out. The local police had an excellent record in solving minor crimes, amazingly good, in fact. They were able to solve most burglaries, although too much time had passed for the victims to be able to get their goods back. All they had was the satisfaction of knowing that the thief had been caught by their outstanding police department.
Then it was revealed that in a number of cases, the people who pleaded guilty to many of the burglaries were clearly not in the state at the time. Some were even in jail in another state when the crimes were committed. They had perfect alibis and were demonstrably innocent. Why would they plead guilty to crimes they did not commit when they could easily prove themselves innocent?
It was the magic of plea bargaining.
These people had been caught for crimes they had actually committed and were sure to be proven guilty. The police and prosecutors promised them that if they went to trial, they would be convicted, and they would ask for and get the maximum sentence, which would put them in jail for a long, long time. There as an alternative, though. They could plead guilty and spare themselves a trial. And if they showed true remorse by pleading guilty to other crimes they had committed, then their potential sentences could be reduced even more. A really cooperative defendant who pleaded guilty to a long list of previously unsolved crimes (like burglaries) could get away with a really minimum sentence.
It was a win for everyone. The criminal got a minimum sentence. The police got cold cases off their books and a commendable rate for solving crimes. The crime victims got the comfortable illusion of thinking their cases had actually been solved. What more could anyone ask from a criminal justice system?