The brother of an American woman who was killed after spending months as a hostage of Islamic State militants says her situation worsened after the United States traded five Taliban commanders for a captive U.S. soldier. Kayla Mueller’s brother told NBC’s “Today” in an interview that aired Monday that the militants increased their demands after the May swap for Army Sgt. Bowe Bergdahl. Eric Mueller says that’s when the militants “realized they had something.” Kayla Mueller’s death was confirmed Feb. 10 by her family and US officials. The Islamic State group claimed she died in a Jordanian airstrike, but the Pentagon said it didn’t know how she was killed.