Generally speaking, God is the final judge, for He is rightous and absolutely holy. God's law, man's conscience, and human consensus combine to shape the Christian view.
There are a number of viewpoints regarding sentencing in Criminal Justice that claim Judeo-Christian status, ranging from very strict to very lenient but properly belonging to this tradition is a far different matter. To my mind, the proper Judeo-Christian response depends on the attitude of repentance found in the perpetrator. A repentant perpetrator deserves a more merciful sentence, but a non-repentant one deserves a harsher one. Judging the attitude of repentance can be a problem though.