It happened in the Madrid subway at the sight of many passengers, but only one couple decided to act. They observed that a boy and a girl were arguing heatedly. When the man went from words to aggression, they went to help the girl. She did not want to file a complaint, but the couple who witnessed the attack went to the police station and, several days later, the alleged assailant was arrested. He has a history of mistreatment and sexual assault.