Ask any lawyer, judge or cop what kind of case they least like to handle or respond to, and I'll promise you that nearly all would say "domestics". These are emotionally-charged, violent laced incidents to be involved in. And, when you're on the outside, attempting to impose order and reason where none exists, the situation is exacerbated.
Such was the case in Stockton, California today, where a batterer on trial for stabbing and killing his girlfriend waited until the jury was recessed, then suddenly made a motion towards the presiding judge, and stabbed her. Deputies shot and killed the assailant, and the judge is doing okay (listed as good condition).