The mentally ill need to be treated in a humane manner. Many are on the streets, so identifying individuals as mentally unstable and getting them into treatment is going to be difficult. Who is going to determine their mental stability?? Usually they are identified once a crime is committed and then they are incarcerated anyways. So ... depending on the crime ..... treatment and rehabilitation is necessary. I don't believe that is the protocol, I believe they are incarcerated, made to do their time and released.
The same protocol is used for drug offenders; they do their time and then let back out on the streets with no rehabilitation or treatment so it becomes and revolving door for the offenders.
It really is a sad state of affairs and one that will take a significant amount of work to make laws that can effectively deal with mental illness. Taking them off the streets and then throwing away the key to me is not an option.