Oregon sheriff treated after 20 suspicious envelopes found across state

PORTLAND, Ore - The FBI is investigating at least 20 letters received by law enforcement agencies across Oregon on Monday after a rural sheriff was hospitalized following exposure to an unidentified white powder in an envelope, officials in the state said.

Sheriff Glenn Palmer of Grant County was exposed to an unknown "chemical substance" after opening a letter delivered to his office, a department dispatcher said.

Palmer was hospitalized after developing a rash and was being treated early Monday evening, said Eric Schmidt, communications manager for the Association of Oregon Counties.