Okay, first off, some stats. Some of these are just for my state or county; some are all across the US. I imagine most other states have pretty similar figures, but you'll see further down that some of them aren't applicable to more gun-wary countries.
Domestic violence accounts for 15% of all violent crime, and it's one of the most lethal -- both for victims, responders, and bystanders.
It most commonly affects women aged 18-24, but women of any age are affected.
1 in 15 kids are exposed to DV every year. 90% of these are direct eyewitnesses. These kids are 6x more likely to attempt suicide.
Men exposed to DV as kids are 3-4x more likely to become abusers themselves. They often use their childhood as an excuse and manipulation tactic.
19% of domestic violence involves a weapon. In this definition, 'weapon' refers to literally any object used to attack or threaten -- from guns to belts.
Pay attention to these weapon stats:
67% of domestic fatalities involve guns (in my county).
15% of domestic fatalities involve knives.
11% of domestic fatalities are caused by blunt force trauma. Blunt force trauma, in most cases, means the abuser beat the victim to death with his bare hands.
Many jurisdictions have implemented, or are in the process of implementing, laws in which domestic abusers' guns are confiscated, either for a certain period of time or indefinitely. While abusers are still able to kill or near-fatally injure victims by other means, taking their guns greatly increases victims' likelihood of surviving. Unfortunately, this practice isn't nearly universal.
Something I didn't know was that in many areas, when a victim goes to file for a protective order, her abuser can come into the courtroom and tell the judge his side of the story. He is allowed to lie and demean her while she is seeking protection. Because of institutionalized misogyny and because of abusers' ability to manipulate the system, they often get the protective order denied -- if the victim even gets to the point of petitioning for one, as the threat of her abuser being present to argue and traumatize her further is a huge deterrent.
Having a victim advocate present can be a game changer.