Nevada law requires anyone ARRESTED for domestic violence to stay in jail for a minimum of 12 hours before he or she can be released on bail or on their "own recognizance." If CONVICTED of first offense (misdemeanor) DV, your fiancé faces a mandatory jail sentence ranging from a minimum of 2 days to a maximum of 6 months. I say "mandatory" but a lot of times the judge will give a DV convict "credit for time served" meaning he will not have to go back to jail. However, I do not practice in Northern Nevada and your description of the event is not too detailed. Your fiancé could be facing much more severe penalties, including a lengthier jail sentence, if you sustained "substantial bodily harm" or a "deadly weapon" was involved. You are not in control of the charges that may or may not be asserted against your fiancé. Although you would most likely be the State's star witness, the State of Nevada (or City of Reno if you are in muni court) will decide whether charges are made and a DV conviction is pursued against your fiancé. That being said, you not wanting to testify against your fiancé could definitely impact the prosecutor's decision to pursue the DV charge versus allowing his to plea to a lesser offense. However, the prosecutor can subpoena you to testify and you must tell the truth at trial. If you refuse to testify, you could be held in contempt of court. I think you meant to ask about the chances of him not getting convicted (instead of "arrested" as you state because he was obviously already arrested). Your fiancé should hire a criminal defense attorney from Reno. His chances depend on a number of things, i.e., did you sustain substantial bodily harm, did he use a weapon, etc. He will probably have to attend DV classes and maybe anger management whether he gets convicted of DV or not (even if he is allowed to plea to a lesser offense, he will still likely be sentenced to the minimum DV penalties (but will probably get "credit for time served" for the jail sentence. Your fiancé needs to hire an attorney.