The first few inauspicious lines to “Happy Accident” by Los Angeles punk rock legend Alice Bag tumble out melodically: “All I saw was the look in his eyes and I feared for my life, once again. I didn’t know what was coming. All I know is he done it before.” The song is about a woman who deals with an abusive partner (something Bag knew about—she saw her own mother get hit by her father and had imagined what it would have been like if she retaliated), and the final line concludes with a “Happy Accident," the death of the man who had hurt her so many times.

Bag’s use of the word accident isn’t one—when a battered woman kills her abuser, it isn’t usually planned. It’s a last-ditch attempt by the woman to defend herself, according to experts—though many battered women who kill are not credited with self-defense but with murder, or, if they are lucky, manslaughter.

That’s because juries and judges “just don’t get that the kinds of violence that [the battered woman] experiences was life-threatening,” says Chitra Raghavan, a professor of psychology at John Jay College for Criminal Justice and a practicing clinician who works primarily with victims of violence. But for women who kill their abusers, their lives are indeed on the line. Eighty-five percent of domestic violence is man-on-woman, and the women are right to be afraid: 4,000 women a year die at the hands of their abusers—75 percent of them because they are trying to leave. "For women, killing is often seen as a last resort—a defensive move, whereas, for men, it's an offensive move," Northeastern University criminologist James Allen Fox told ABC News in 2009.

"Those who have less to lose, those who are suicidal (the link between homicide and suicide is very clear), those who are protecting children, and those whose partners have threatened to kill them, are at highest risk."

Self-defense laws require an immediate danger of physical harm and were originally designed for conflicts between men: a man killing another man of equal strength in, say, a bar fight, according to Cynthia Gillespie, a lawyer who co-founded the Northwest Women’s Law Center in Seattle in 1978 and authored the 1989 book Justifiable Homicide: Battered Women, Self Defense, and the Law. But those laws don't reflect the reality of domestic violence situations and don't make sense, Gillespie has said, "for a woman trying to defend herself from a man who has threatened to kill her before." (The argument Gillespie made in her book led then-governor of Ohio, Richard Celeste, to grant clemency to 26 women serving prison sentences for killing husbands or partners in 1991.)

TAKE CAROLINE SCOTT: HER drunk abuser, Arthur Lee, came home in a jealous rage and indicated that it was time for her to put on her handcuffs, the precursor to severe beatings that had become more intense over time. With small children in the house, she couldn’t figure out how to make an exit and didn’t want to leave them behind. She overheard Lee on the phone tell a friend that she would be “gone” in 45 minutes. Terrified of what she knew was coming, she grabbed one of Lee's guns and shot him to death, as Gillespie outlines in Justifiable Homicide. But because he wasn’t directly beating her at the moment she pulled the trigger, Scott was sentenced to 20 years in prison.

Bag’s song was written in 1990—almost 25 years ago now, but when it comes to women who kill their abusive husbands in self-defense, not much has changed since then or over the past 300 years. It’s like a horrible, bloody diorama—the outside world moves forward, but the dynamics of this particular set of criminal circumstances don’t change. “This phenomenon seems to stay the same over time,” says Gertie Pretorius, director of the Centre for Psychological Services at the University of Johannesburg.

Compare Scott’s more contemporary story to that of the long-abused Jane Churn, who dealt with similar circumstances in the late 18th century. They're detailed this way in Murray State history professor Kathy Callahan’s 2013 Journal of Social History analysis:

When Jane Churn ignored her lover James Scofield's question, he called her a ‘bloody bitch,’ struck her several times, and the two fell onto the floor, fighting. Churn stood up, grabbed a fork from a nearby table and stabbed him with it. Still angry, she followed him down the stairs and hit an already-downed Scofield with a poker.

Churn was eventually convicted of manslaughter and sent to London’s infamous Newgate prison.

Women tend to fight back with whatever weapon is at hand—in the United Kingdom, where gun ownership is lower, other weapons are used. But “women still are most likely to use a gun, often the same gun he uses to terrorize her,” says Lenore Walker, a lawyer and professor at Nova Southeastern University Center for Psychological Studies who literally wrote the book on domestic violence: 1983’s The Battered Woman Syndrome. “You don't need to be too close, you can stop him from continuing the battering incident, and you don't need to have upper body strength like strangulation or knife requires," she says.

What’s common to all these stories, no matter the era, is that abused women who kill their partners do so in reaction to extreme circumstances—escalating abuse is the most common one, and so is the protection of children or other household members. “In many of the cases we have on record in which battered women killed their abusers, the batterers had made sexual advances to, or had actually sexually abused, one or more of their children,” Walker writes in her 1989 book Terrifying Love.

It’s no surprise then, which abused women are most likely to fatally hurt their abusers: “Those who have less to lose, those who are suicidal (the link between homicide and suicide is very clear), those who are protecting children, and those whose partners have threatened to kill them, are at highest risk,” Walker says. Women whose cases haven’t been taken seriously by local law enforcement, or that involve use of alcohol or drugs (by either or both parties), are also more likely to kill (though substance abuse plays a smaller role than might be guessed).

AS WITH RAPE, THE abused woman narrative blames the victim, and this kind of violence is unlikely to change unless public understanding—and the law—do too. There’s an oft-ignored psychological aspect to domestic violence situations, which bear very real parallels to terrorism writ large. (Some domestic violence advocates even call it intimate partner terrorism because the connections are so clear.) A combination of a small dose of violence, threats of more, coupled with enforced control over the woman’s autonomy very effectively traps women in these relationships. It’s not all that different from the way terrorists operate when considering a beheading. They know the action alone will change how they are treated by the international community—this is how terrorism works. For some reason, people understand it when it comes to ISIS—but have trouble applying the logic of terror on an individual basis.

The most frequently asked question remains: Why didn't she leave? Judges ask it, juries deliberate it, people watching the nightly news consider it. Although psychologists and many police departments have better training in domestic violence (Raghavan says mental health professionals are “light years” ahead of where they were 50 years ago), the question shows the rest of us don’t. “Leaving does not stop the violence and may in fact make it more likely that she and/or her children will get killed,” Walker says. “The real question is, ‘Why doesn't he let her go?’”

Since the law doesn’t protect battered women who try to leave, and the courts prosecute those who stay and kill in self-defense, women are more than just limited by their finances, children, or the threats of their abusers—they may feel that there’s no way out, which is why some of these women end up killing themselves, too. To top it off, there have even been cases in which women have been found negligent for failing to protect their children from abuse by a third party.

“The best preventative strategies will involve a holistic approach including women and men, as well as children who grew up in violent homes,” says Pretorius, the University of Johannesburg expert. Those who have experienced abuse growing up are more likely to accept it as normal behavior, as both an aggressor and a victim.

The holistic approach needs to include legal fixes, too. "I think the law should more systematically [recognize] intimidation and fear as creating huge power imbalances between people in domestic violence situations," Raghavan says.

Restraining orders can be a part of that mix, both formalizing and documenting the abusive behavior, and also empowering battered women. A 2002 study published in JAMA and led by Dr. Victoria Holt, an epidemiologist at the University of Washington, points out that although restraining orders keep lethality down, “research suggests that a small proportion of women obtain restraining orders and ... that most women did not have a restraining order when they were killed. Only 11% of 231 women killed by their intimate partners had been issued a restraining order.”

Indeed, threatening or preparing to leave an abuser is one of the most dangerous situations these women can put themselves in—these are men who often control the minutiae of these women’s lives. It’s common for them to micromanage schedules, time with friends and family (if they have not already been cut off from them), and even access to a car and money.

IN 2012, ENGLAND PASSED a law recognizing coercive control and making it a prosecutable offense. “This is essentially a chronic control dynamic that robs the woman of her autonomy over time and traps her in the relationship,” Raghavan says. It’s this kind of control that begins most abusive relationships, which rarely start off with physical force.

But in the United States, most of these tactics aren’t currently recognized by any laws and aren’t targeted for intervention—indeed, there’s little education for young people about this issue at all, even though nearly one-third of American women will be abused by a partner at some point in their lives. If we do want this narrative to change, coercive control within intimate relationships needs to be discussed. “These tactics include forms of constraint and the monitoring and/or regulation of commonplace activities of daily living, particularly those associated with women’s default roles as mothers, homemakers and sexual partners and run the gamut from their access to money, food and transport to how they dress, clean, cook or perform sexually,” Evan Stark, a professor at the Rutgers School of Public Affairs and Administration, writes in a 2012 paper.

By ignoring or minimizing the tactics used in coercive control, current domestic violence laws also miss many of its most devastating effects.

Battered women (and children) see a tremendous psychological toll. And more frequently than a woman kills her abuser, a man murders the woman he has been abusing. Beyond lost lives, there’s an economic cost too—and it’s huge. According to a study by James Fearon of Stanford University and Anke Hoeffler of Oxford University, abuse of women and children totals about $8 trillion in losses each year—or about nine percent of global GDP. It’s clear why the United Nations and other organizations are finally starting to take this problem more seriously.

For anything to change, a much larger, seismic shift needs to occur, as Mary Helen Wimberly suggests in a paper for the American Bar Association:

The focus ... should change from emphasis on the personal syndrome to emphasis on the larger societal syndrome that has placed the battered woman in a situation where her only option was to kill her batterer. The necessity of her actions was caused by the community, and experts should point to the failures of society and the government at large to offer battered women reasonable alternatives. This goes to the heart of the theory of self-defense as one of necessity, and shows that the battered woman’s actions should not be “excused” because of any personal ailment or shortcoming, but should be recognized as justified because of the situation in which she was placed.

Until then, as the last lines of Alice Bag’s “Happy Accident” (after listeners learn the character is singing from her prison cell) suggest, more women will continue to see the true value of the kill: “I can’t say that I regret it. After all, it’d be him or me you’d be talking to. And if I had the chance to do it all again, I don’t think it would have a different end. I’m quite happy with this accident.”