The suggestions to the query fall under two counts -
Firstly, if, during the process of selection and appointment, you were required to furnish the information as to pending criminal cases and you did not furnish the correct or complete information, the lapse amounts 'suppression of information'. Such a lapse amounts to deficit in integrity and is certainly, a misconduct.
Secondly, if the trial ends in conviction, the offence involves moral turpitude and you are liable to terminated.
However, the facts posted suggest the complaint has stemmed from because of physical relationship with the alleged promise to marry. In the present days of live-in relationship, the Courts are adopting a rather liberal attitude esp. if the girl is no longer a minor and well-educated who could have been very well aware of the consequences of her consenting act.