Suspicious letters sent to President Obama, U.S. senator

A letter addressed to President Obama containing a "suspicious substance" was intercepted on Tuesday at a remote Secret Service mail screening facility, the presidential protective agency said today. The letter was received on the same day that a different letter suspected of containing deadly ricin was received by a congressional mail screening facility.

The FBI said that the granular substance in the letter to Obama tested positive for ricin in a preliminary test.

A letter addressed to the office of Sen. Roger Wicker, R-Miss., contained a suspicious substance that might have been potentially deadly ricin, the FBI said Tuesday, sparking new fears of security threats in Congress at the same time the country was reeling from the terror bomb attacks in Boston.

The letter, discovered at a mail facility in Landover, Md., just outside Washington, was field-tested positive for ricin, according to an FBI official who spoke on condition of anonymity in order to candidly discuss the inquiry. While cause for alarm, that test was not conclusive, the official said.

Another law enforcement official familiar with the investigation said that the letter contained both a threatening letter and a powder. Four tests were done in all, two were positive for ricin and two were negative, he said.

The official, who asked not to be identified because he was not authorized to discuss the investigation, said the conflicting tests suggested that the powder might not be poison. Additional tests are being done that are not yet complete. "I’d be shocked if it were ricin," he said.

The postal facility where the congressional mail is inspected, he said, was having a problem with tests that erroneously show the substances as poisonous. "The facility is famous for false positives," he said.

The official also said investigators have found no link between the threatening letter to Wicker and the bombings in Boston.

Officials said the letter was postmarked in Memphis, Tenn., and sent to the Washington office of the Mississippi Republican. It was sent first to a special testing facility far from the U.S. Capitol and never made it to the senator’s office

“I want to thank our law enforcement officials for their hard work and diligence in keeping those of us who work in the Capitol complex safe,” Wicker said in a statement Tuesday evening.

News of the contaminated letter, coming a day after the explosions at the Boston Marathon that killed three, shook the Capitol. Senators were briefed by FBI and Homeland Security officials about the letter at an early evening session called to inform them about the Boston explosions.

Capitol Police, the FBI and other agencies were investigating. There was “no indication that there are other suspect mailings,” according to Senate Sergeant at Arms Terrance Gainer.

Gainer said “exterior markings on the envelope in this case were not outwardly suspicious, but it was postmarked from Memphis, Tennessee, and had no return address.”

Tuesday’s news recalled a similar scare in 2001, when two letters postmarked in New Jersey and containing anthrax were sent to Senate Majority Leader Tom Daschle, D-S.D., and Senate Judiciary Committee Chairman Patrick Leahy, D-Vt.

The congressional mail service was briefly shut down, parts of the Capitol were declared off limits, and workers there had to take medication.

Since then, congressional mail has been screened offsite, and Gainer said Tuesday the Senate offsite facility will be “closed for the next two to three days while testing and the law enforcement investigation continues.”

For years, mail also has been treated with radiation to kill biological threats, though it could not immediately be confirmed whether that still occurs.

Ricin, toxic and derived from castor beans, can be easily and inexpensively produced. Law enforcement and terrorism experts say it’s more effective on individuals than as a mass weapon. It only takes a small amount to kill a human being, and there is no specific test or antidote.

Ricin poisoning is not contagious, and touching the substance would cause little harm. But eating after touching ricin could be harmful.

According to the Centers for Disease Control and Prevention, unintentional exposure to ricin is highly unlikely. Death from inhalation or ingestion, if not quickly treated, could come within 36 to 72 hours, the CDC says.

Within a few hours of inhaling significant amounts of the substance, symptoms likely would include difficulty breathing, fever, cough, nausea and tightness in the chest. Heavy sweating may follow, as well as fluid building up in the lungs that would make breathing even more difficult and could turn the skin blue, ultimately leading to low blood pressure and respiratory failure.

Ingestion of a significant amount, the CDC says, would likely lead to vomiting and diarrhea, possibly bloody, within a few hours, resulting in severe dehydration and low blood pressure. Within several days, the person’s liver, spleen and kidneys might stop working, and the person could die.

Wicker, 61, has been a U.S. senator since 2007. A quiet, reliable conservative, he’s a deputy whip, meaning he helps Republican leaders round up Republican votes. He sits on the Armed Services, Budget, Commerce and Environment and Public Works Committees.

He came to the Senate after serving seven terms in the House of Representatives, and prior to that, the Mississippi State Senate. An Air Force veteran and native of Pontotoc, Miss., he’s the son of a former circuit judge.

The Senate is debating gun control legislation and plans to vote Wednesday on amendments.