Juan Francisco Lopez-Sanchez, also known as José Inez García Zarate, is a felon who has been deported five times. Lopez-Sanchez is charged in the shooting death of Kathryn Steinle, 32, by all indications a distinguished and compassionate woman. As it happens, victims of foreign nationals in the United States illegally are not limited to innocent civilians. They include police officers such as Danny Oliver. Last October, Luis Enriquez Monroy Bracamontes, a Mexican national in the United States illegally, gunned down Oliver, 47, a Sacramento County Sheriff’s deputy. Bracamontes shot Oliver in the head with a 9mm handgun but the...