The envelope arrived Monday, and the agency did not announce to whom the letter was addressed. Further tests are being conducted to confirm the initial results.
Four months after he was brought back to an agency that was struggling to cope with a series of embarrassing missteps, Joseph Clancy was named permanent director of the Secret Service on Wednesday.
The new Authorization for the Use of Military Force, or AUMF as it's known, bans the use of U.S. forces "in enduring offensive ground combat operations."
President Obama says it would break protocol to meet with Israel's prime minister just two weeks before Israeli elections. The two leaders have developed a prickly relationship over the years.