I can't do much more than strongly agree with Grampster, Mike, and 280 on their excellent, well-met points. Paper trails are your friend if the reprobate comes a'callin' in the middle of the night and gets a mug full of birdshot at your threshold.
You might consult your best attorney for advice on some manner of joint and several order with intention of keeping him away should he (and most likely is) get out on bond. It puts teeth, albeit small ones, where there are already some smallish ones to begin with. Yes, it will infuriate a nutjob. It makes most rational people irritated. Any person who strikes an old person, let alone their mother, is as imbalanced as a V-6 hitting on 4 random cylinders. If your ex does follow a wiser path and put an order against him, it would likely make your case for full custody stronger.
I would be sure to not mention that aspect to her.
BTW, I don't put a lot of faith in Gavin DeBecker. I prefer Bill Jordan's philosopy considerably more, as it's not so 'fluffy', I'll call it.
When's the last time you rekeyed your locks on the house, anyway?
Regards,
Rabbit.