You can't design a system that is mistake free, but that can't be the basis for a abandoning a punishment/deterrence system altogether.
At some point you have to trust that you've implemented reasonable safeguards and that you've minimized the chances for wrongful conviction. After that, you can console yourself by recognizing that most wrongful convictions happen to bad people, not to completely innocent, law-abiding people.
"I'll see you guys in New York." ISIS Caliph Abu Bakr al-Baghdadi to US military personnel upon his release from US custody at Camp Bucca in Iraq during Obama's first year in office.