Mental Illness in and of itself does not cause anyone to break the law.

Nice word ValentinaVVV

Anyway, as I personally see it:

Being we are in a BP thread, and it is something I know about, let's use BP as an example.

When we are in our "off" states, we look for ways to help us feel better. Those of us that have healthy cognitive interventions, and know how to keep an eye on our cycles, seek out healthy ways to circumvent the "poor me feelings" that seem to so often lead to unhealthy behavior.

Then some just don't know how, won't go to therapy, and feel they can justify what they were doing because "I am BP".

No, BP does not make you a criminal. It's the unhealthy thoughts and feelings that are not dealt with that lead you down a path of criminal behavior. At anytime, up until you actually commit the crime/do the unhealthy behavior, you can choose not to do so. It is your choice to follow through.