Kayla Mueller was a 26-year-old aid worker from Prescott, Arizona. She was not a thrill-seeker. She was the kind of person drawn toward suffering with a medical bag and a stubborn belief that people ...

ISIS said in February that Mueller, of Prescott, Arizona, was killed when Jordanian fighter jets bombed a building where she was being held outside Raqqa, a stronghold in Syria of the Islamist ...