"Police lying raises the likelihood that the innocent end up in jail — and that as juries and judges come to regard the police as less credible, or as cases are dismissed when the lies are discovered, the guilty will go free."
I'm not sure why the police protect each other when there is wrongdoing. When that stuff eventually comes to light it reflects badly on the entire group. Sure, we can tell people it's just a few bad apples, but that doesn't really hold up when the group continues to support bad apples. They're being complicit.