I am a lawyer in CT and practice in this area.  Most employees, like yourself (based on the facts given) at "at will" employees.  This means that they can be fired for good bad or no reason at all absent discrimination (i.e. race, age, sex, religious beliefs).  Therefore, if your boss found out about the arrest in and of itself, you could be fired.  In fact, any employer that learns about the arrest can fire you at any time without notice. The employer did not violate the law if he fired you due to the arrest.