The sad part is the victim frequently is so financially dependent for themselves and any children that they don't feel they have a choice to leave. They take the beating for the money and usually only a limited amount at that. Food and shelter at the cost of being a punching bag.
Here we're much like LZ mentioned. If there's obvious signs of injuries an arrest is mandatory. After that basically the officer can be the complainant and can possibly go to court without the victim. Still the punishment generally isn't enough and not enough protection for the victim after the fact.
Things are improving slowly. Now it's common if requested for the victim to be notified that the abuser is getting released. Usually a protection order is almost a given which may or may not do any good.
In Memory of Paul "Dietrich" Stines.
Dad: Say something nice to your cousin Shirley
Dietrich: For a fat girl you sure don't sweat much.
Cue sound of Head slap.
RIP Muggsy & TMan
"If you are a warrior legally authorized to carry a weapon and you step outside without that weapon, then you become a sheep, pretending that JOCKO will not come today."