You are absolutely right about the system as it stands. They say that "Justice is blind" and in being blind, it sometimes makes horrendous mistakes.

The thing we really need so far as justice is concerned in this country, as highlighted by the case currently ongoing in North Carolina, is some form of oversight for the DA's. I've seen these people try cases that shouldn't have ever been tried, just for political reasons, not caring that they're ruining lives.
I saw one instance where a man murdered another. The murder occured within the presence of an ex-cop, who panicked, and didn't do anything to report the crime, making him an accessory. When the case came to trial, the DA made a deal with the murderer, giving him 8 years for assault with a deadly weapon, in order to go after the ex-cop, so that the DA looked better in the newspaper. Both men should have gotten impartial treatment under the law for the crimes they committed, instead of the true killer getting a slap on the wrist, so that the DA would look good in the news.

Another case: A boy and girl were dating, and having sex wth her parents knowledge. the boy was 17, the girl 16. When the boy turned 18, her parents told him he had to marry the girl. When he refused, saying he wanted to wait till they had both graduated high-school, her mother filed statutory rape charges against him. The local DA, seeing headlines, prosecuted the case successfully. This made him a convicted child molestor.

There is a lot that should be done to revamp the system, and I don't propose that we should exact revenge, but when a person has clearly committed a crime, there should be some form of PUBLIC punishment to be used as a deterrence. I realize publicity doesn't deter all of the potential criminals out there, but it may reach more of them than we realize.

As to God's revenge. Of course He is the final Judge for all of us, and His punishments are not all eternal. He does punish, in this life, as well as the next one. We should punish criminal behavior, but leave the revenge to Him.