Innocent people are being wrongly convicted

Innocent people are being wrongly convicted without sufficient evidence. This is a big problem in the USA. Not everyone can afford a good attorney and you have your public defenders who are suppose to protect you, but because they are overwhelmed with so many clients they don't even remember your case and will do anything to move on to the next case. We as the people should help the innocent. Why is it so easy for information to be falsified to hurt the innocent? For example football player (Brain Banks) who was innocent, he was convicted and did time in prison. All for what because of a lie. We need to defend the innocent.