Whatever you do, it's the right thing to try to help her out. You stated that your wife has several relatives "on the job". Ask them how things are handled in NY vs. Utah. Being involved in a DV assault situation does not necessarily mean you're going to jail. The officers who respond, and the prosecutors, are going to look at the totality of the circumstances and determine what was and was not reasonable behavior. However, this post/poll does indicate a level of premeditation on your part. Offer her a ride to your home or to a shelter and let the NYPD deal with the sh!tbag. If he needs to be tuned up they're old pros at it and will do it legally. Just another $.02