I don't know of any specific cases off hand, but an example I've used in the past would be, for instance, a person who steals food to feed his children. Technically a crime, but a case of desperation in which a (probably) good person feels forced to commit a criminal act.
You also have to define your terms. Is a criminal someone who has committed a crime, or someone who has been convicted of a crime? We know there have been people in prison who were convicted wrongly, and later released. Are they criminals?
And there are cases of people being convicted of breaking unjust laws. In some states in the US a 16 year old boy having consensual sex with his 15 year old girl friend is committing a crime! Does that make him a criminal?