From the young woman brutally murdered and dismembered in a short-term rental apartment to the Olympic runner set on fire by her estranged boyfriend, a surge in violence against women in Kenya has spurred many to prepare themselves to fight back.

NAIROBI—Last September, Ugandan Olympian Rebecca Cheptegei lost her life in Kenya at the hands of an intimate partner. Cheptegei’s partner, Dickson Ndiema, poured petrol on her and set her on fire during a disagreement at their home. Her mother, Agnes, had dreaded this moment for years.