A schoolboy wrongly accused of two murders
bbc.com
bbc.com
However, it is commonly abused by prosecutors pressuring less obvious cases into pleading guilty. People who may well be innocent but can't afford decent representation, are so afraid of the potential 20yr sentence that they plead out for 6 months in minimum security.
So yes, every guilty person should plea bargain (unless they have great lawyers), but unfortunately the plea bargaining system means a significant number of potentially innocent people are pressured into pleading out.
Not a particularly just system.
That's why I was saying that it's not a good sign for a justice system if plea bargains are better for innocent people. They're only meant to be better for guilty people, in order to speed up processing in overburdened courts.