Question

criminals are wicked and deserve punishment

Answer 1

people think that criminals are wicked but they might be good at some point of time. Due to some wrong done to them, they may have adopted the wrong way of getting justice.

Answer 2

To quote Mohandas Karamchand Gandhi, the father of our nation, "Forgiving is more courageous than punishing. The weak cannot forgive; forgiveness is the prerogative of the strong."
Although criminals do make blunders and crimes, this reflects their wrong, rather different, perspective of crime. The must not be punished; instead, they should be enlightened about the "goods" in life and should be given another chance to walk on the path of goodness and virtuousness.
So, I would like to conclude by saying that, criminals are guileless and not wicked, and that they deserve, not punishment, but learning.