Letter sent to Obama tests positive for ricin: FBI

WASHINGTON – Agence France-Presse/The Associated Press

Police cordon off the area in front of the White House in Washington DC, on April 17, following attacks at the Boston marathon. AFP photo

A letter addressed to US President Barack Obama has preliminarily tested positive for the deadly poison ricin, the Federal Bureau of Investigation said April 17.

In a statement, the FBI said the investigation into the letter sent to Obama and another sent to Senator Roger Wicker was ongoing, adding there was "no indication of a connection" to the Boston Marathon bombings.

The FBI said additional tests would be carried out over the next 24 to 48 hours to confirm the presence of ricin. Ricin, when inhaled, can cause respiratory problems. Ingested orally, the protein is lethal in even miniscule quantities.

The US Secret Service said the letter had been intercepted at a mail screening facility outside the White House on April 16, the same day authorities said a letter was sent to Wicker that also showed traces of ricin.

The letters sent to Obama and Wicker are related and both are postmarked Memphis, Tennessee, according to the FBI.

Letters postmarked before Boston marathon

In an intelligence bulletin obtained by The Associated Press, the FBI says letters to Obama and Sen. Roger Wicker both say: "To see a wrong and not expose it, is to become a silent partner to its continuance." Both letters are signed, "I am KC and I approve this message." Similar "I approve of this message" wording is often used by candidates at the end of political ads.

The activity came as tensions were high in Washington and across the country following the deadly bombings on April 15 at the Boston Marathon that killed three people and injured more than 170. The FBI said there is no indication of a connection between the letters and the bombing. The letters to Obama and Wicker were postmarked April 8, before the marathon.

Sen. Claire McCaskill said police suspect a person who "writes a lot of letters to members." She made the comment April 16 as she emerged from a briefing by law enforcement on the Boston bombing. Authorities declined to comment on a suspect.

In addition to the letters, U.S. Capitol police were investigating the discovery of at least three suspicious packages in Senate office buildings. Senate Sergeant at Arms Terence Gainer said in an email that packages were dropped off at the offices of two senators, and Sen. Richard Shelby said in a statement his office had received one of them.

Capitol Police later said results of tests conducted at the Hart Senate office building were negative and the closed-off areas were reopened.

US Capitol Police confirmed one man was being questioned. "Right now they are interviewing a person but that person is not in custody. He has not been detained," a US Capitol Police officer told AFP.

The episodes recalled the mysterious series of letters laced with anthrax that were sent to lawmakers and some journalists following the September 11 attacks in 2001, which killed five people and sickened 17 others.

Congressional mail has been screened off-site since the 2001 incident. Three Senate office buildings were shut in 2004 after tests found ricin in mail that had been sent to the Senate majority leader's office. The biological agent was also sent to the White House and the Department of Transportation in November 2003. There were no injuries in those incidents.