If you defend a client by reason of insanity, in your argument, can you agree that your client committed a crime?

What you are really doing when you raise an "insanity defense" is not arguing that your client did not physically commit the criminal acts, but rather arguing that your client did not have the requisite mental state to commit a criminal act.  Most crimes require proving two elements to sustain a conviction--that the act itself occurred as well as having the mental state to commit an offense.