The FBI on Wednesday took into custody a former U.S. Navy sailor suspected of mailing envelopes containing potentially toxic material to the Pentagon and the White House. The suspect has been identified as William Clyde Allen III of Logan, Utah, the Utah U.S. Attorney’s Office confirmed to The Hill. “Federal prosecutors in Utah authorized a probable cause arrest of Mr. Allen this afternoon. We anticipate filing charges Friday,” office spokeswoman Melodie Rydalch said in a statement. Chief Pentagon spokeswoman Dana White said Wednesday that multiple letters mailed to Defense Secretary James Mattis and Chief of Naval Operations John Richardson contained...