In 1995, Trish Hoffman joined the Albuquerque Police Department after ending a relationship with an abusive ex-boyfriend. Her motivation: After filing multiple police reports that led to zero action, she decided to just become an officer herself so she could help women who were going through similar situations. Since then, she's also formed a nonprofit, Women Against Crime, providing free self-defense classes for women since 2005. And now, as part of the Refinery29 original series Sergeant Trish Hoffman's Self-Defense Course, we're bringing her classes directly to you. Sadly, there's a solid chance that you might one day need these techniques. According to the National Coalition Against Domestic Violence, a woman is assaulted or beaten every nine seconds. As many as one in five women has been raped in her lifetime, and 19.3 million women have been stalked. "Women (and men) really are completely capable of protecting themselves when they're put in a situation where they have to defend themselves," Hoffman explains in the short above. "That truly is why I do this class. The impact it could have on someone could really be life-altering." On top of that, for some women who've experienced a sexual assault or been a victim of another crime, learning self-defense techniques can help them find peace of mind and reconnect with themselves in the aftermath. (Caveat: for others, self-defense classes can be triggering, so make sure you're ready to tackle this project.) Watch the video above to learn more about Hoffman's mission, and check out the seven safety tips you should know here and here.