The family of Robert Davis, 19, who is accused of killing local journalist Josh Kruger, said that Davis was just 15 when he and Kruger began a years-long relationship involving drugs — and that Davis told them Kruger was threatening to post sexually explicit videos of him online before, police say, Davis shot Kruger. Those assertions by Davis’ mother and older brother in recent interviews with The Inquirer add troubling new complexities to a killing that has garnered national attention. Their account, they said, is drawn from recent conversations with Davis, and from the years of watching his life unravel...