He can be charged with a crime, no matter what. His defense attorney can raise the mental health issues either to convince the prosecutor to dismiss in favor of treatment or as a legal defense if the case goes forward. You need a criminal defense attorney. A defense attorney will be used to cases involving mental health issues.
We do not have a client/attorney relationship until you make an appointment, we discuss your case face to face, I accept a retainer, and we explictly agree to enter into representation.
As attorney Poulson notes, there is a difference between being charged and being found incompetent. Unfortunately, it sounds as if your husband has a serious mental illness and the criminal justice system is poorly equipped to deal with them. You will need a good attorney who is familiar with the law and who is comfortable with the mental health system.
I am licensed in New Mexico and Pennsylvania, and therefore any discussion of issues related to other states must considered within that context. In addition, my comments are not intended to create a legal representation but merely to respond to the limited facts presented by the question. Any opinion herein is not meant as a precise statement of legal rights or as a recommendation of any particular course of action. A more complete legal review can be obtained through local counsel.