I am a lawyer in CT and practice in this area of the law.  The time to ask for a public defender is at the first court appearance.  You will have to explain to the court that you would like a continuance to obtain and complete an application for a public defender. The court will give you a few weeks to apply and retain a PD.After the court grants you a continuance, go to the PD's office in the court house and apply for a PD.  you will know that day if you qualify.  you are facing a charge that will likely result in a dismissal if you complete some alcohol classes.  however, you should have an attorney to represent you to make sure you get into this program.