American hostage Mueller’s family, U.S. government say she is dead

WASHINGTON, (Reuters) – U.S. aid worker Kayla Mueller, held hostage by Islamic State militants for 18 months, is dead, her family said yesterday, but the circumstances were unclear and President Barack Obama vowed to hunt down the culprits.

Mueller’s family received an email and photograph over the weekend from her captors that enabled American intelligence to determine that she had been killed, U.S. officials said.