Instinct to Kill (2001) on Netflix

Plot summary

James Becket is a serial killer, and he escapes. He killed his own father, a man whose expectations he never fulfilled. Detective Difford and his task force take on the search for him, but Becket is too good at disguising himself and at deception for the task force to follow. Becket especially targets his wife, Theresa, who is known as Tess, and her family. Former cop J.T. Dillon was already training Tess in self-defense. He becomes her lover, and he is the one man who proves able to fight back in Becket's league.