I probably mis-spoke. I'm not a lawyer - I hate those. All of them. Every one of them.
Anyway, Isn't it highly unlikely they could get a conviction without a cooperative witness in a DV case?
As hopefully a tolerable lawyer (to you at least), I would say, yes, it is highly unlikely. The scenario would almost certainly require direct eye witness testimony. Statutory construction can help illustrate why this is so.
Most 'Battery' statutes, and that's how many state's charge these cases (some call it 'Assault'), include the following language:
Actually and intentionally touches or strikes another person against the will of the other; or (maybe it includes this)
2. Intentionally causes bodily harm to another person.
You can see the problem when you don't have a cooperative witness/victim.
The Prosecutor must introduce testimony that the battery was 'against the will' of the victim.
(something like this) DA: Ms. Victim, how did you sustain your injuries? Ms. Victim, did you give the defendant permission to strike you?
If you don't have this, and of course then afford the Defendant their constitutional right to cross-examine the accuser, you don't have a case. It would be quite difficult to win a case like this, w/o getting too deep in the weeds, the introduction of hearsay is challenging, without hitting certain exceptions (mainly availability of a witness). Unless I could establish that the victim had vanished, and was legitimately unavailable, I'm gonna get crushed by the defense counsel.
I just checked, I had four battery cases in the fall of 2003, 2 of my victims refused to testify, or even contact the office after we filed the case. So I had a police report, pictures, physical evidence, but at a trial, I have got very little. why? All I could do is call to the stand the police officer who took the complaint, interviewed the Vic, took the pictures. It's her version of events (not under oath) presented to a law enforcement officer in a police report, without a witness to the actual battery, since she won't testify. The cop swears in an affidavit, and that's good enough for arresting and charging the case. For all we know her sister or jealous ex boyfriend roughed her up. I can't place the defendant at the home when she sustained the injuries. I could roll in twenty five friends of hers with text messages, still not good enough.