It comes out of no where. You're sitting with your family having dinner, and the police show up at your door. It seems your wife has - for any reason or for no reason whatsoever - decided to make a complaint against you. She tells the police you threatened her, and she feels afraid.
From that point on, you're at the mercy of the police and court system, and any constitutional presumption of innocence doesn't apply to you. Since your wife says she feels afraid, the police have no choice but to take you out of the house in handcuffs. Since you've now been arrested for "domestic violence" your wife can easily get a restraining order against you, preventing you from ever seeing your kids again.
You can thank Joe Biden - one of the sponsors of the Violence Against Women Act - for the situation you are in. The VAWA ensures that she has the full weight of the legal system on her side. You can be dragged out of your house and separated from your children based on nothing other than her say so.
But even that isn't enough for Joe. Now he wants to be sure that your wife has the benefit of free legal council so she can sue for total custody and child support payments.
This is why any man that thinks the Democrats have their interests in mind is nuts. The only families the Democrats care about are families headed by single moms and gays.