Federal investigators are looking into a possible connection between a letter containing the deadly toxin ricin that was delivered to Senate Majority Leader Bill Frist's office and a letter with the same poison intercepted at a White House mail facility in November, law enforcement officials disclosed yesterday.
Together, the two incidents re-ignited fears from the anthrax attacks of 2001, and law enforcement and health officials from a multi-agency task force said yesterday they had opened a criminal investigation.
Authorities cordoned off all three Senate office buildings, canceled hearings, stopped all congressional mail service and forced senators and staffers into cramped workspace in the Capitol or at home to work from cell phones and laptop computers.
The three office buildings are expected to remain closed for at least the next few days.
There was no sign yesterday that anyone had become ill from the ricin, which can take up to 72 hours to cause sickness. Officials said they were more optimistic, with each passing hour, that no one will be affected.
Agents from the FBI suited up last night in hazardous-materials gear and prepared to enter the Senate Dirksen Office Building to retrieve evidence and determine how the powder, most likely in a letter, entered the building.
"Although anthrax is a very different agent than ricin, all of us in this community lived through that," Frist said of the 2001 anthrax letters that briefly shut down Congress. A spate of letters containing anthrax killed five people elsewhere in the country and sickened 17 others.
"We know the impact it can have in terms of terror, in terms of making all of us feel less secure, in terms of affecting a community directly," the senator said at a news conference. "And we have seen the range of terror, all the way through to death, caused by a biological agent which was directed at the United States Senate."
Law enforcement officials said they would try to determine whether the ricin found in Frist's office is connected to the White House letter in November. That letter, addressed to a transportation official and sent from the southeastern United States, was intercepted before it reached the addressee, who has not been named. A source said the letter was not addressed to President Bush.
Law enforcement officials have linked the November letter to a third letter sent from a post office in Greenville, S.C., to the U.S. Transportation Department on Oct. 15.
In the Greenville letter, the sender, describing him or herself as "a fleet owner of a tanker company," enclosed a metal vial of ricin and demanded that new federal regulations mandating more rest for truckers as of January be repealed.
"If my demand is dismissed I'm capable of making Ricin," the letter said.
The author expressed anger over a new law that requires interstate truckers to get 10 hours of rest between stints of driving, not eight. Law enforcement officials noted that the Senate was scheduled to debate a key transportation bill yesterday.
Meanwhile, authorities in Wallingford, Conn., were awaiting the results of a test to determine whether a gray powder found spilling out of a business reply envelope at a mail distribution center was ricin. The letter was addressed to the Republican National Committee. No illnesses have been reported, and the postal center remained open yesterday.
Capitol police took powder samples from Frist's office on Monday but left the rest of the office untouched. FBI spokesman Ed Cogswell said agents could not get into the office until they knew definitively what substance they were facing. Senate staffers found the powdery substance spread among a pile of about 30 letters in the Republican majority leader's office Monday afternoon, though officials said they were not able to single out yet which letter, if any, contained the poison.
Capitol Hill Police Chief Terrance W. Gainer said officers saw nothing suspicious, beyond the powder, upon their entry.
"There was nothing on first blush that would lead us to believe that there was any visible threat," such as a note or warning near the powder, he said.
Ricin, which is derived from the castor bean, is not contagious and rarely kills if it is inhaled. But health officials said that, if even a little is injected, or ingested in slightly larger quantities, it can cause severe vomiting, fever and respiratory problems, and ultimately lead to death. There is no antidote and little effective treatment, authorities said.
Definitive tests to identify the suspected ricin were performed Monday night and into yesterday morning at the Naval Medical Research Center in Silver Spring, according to a Defense Department source. The tests, called polymerase chain reaction found the DNA of the ricin-producing castor bean plant, confirming the presence of the poison, the source said.
The U.S. Army Medical Research Institute of Infectious Diseases at Fort Detrick, in Frederick County, is also studying the samples, performing electron microscopy tests to determine its particle size. That information will enable investigators to learn more about the ricin used, how it was prepared and possibly compare it to samples from the October and November incidents.
Dozens of Senate staffers had to be decontaminated Monday night with mobile showers. Authorities suspect that only seven or eight people were in the immediate vicinity of the powder, but they cast a wide net in case any of the powder traveled.
So far, there is no indication it spread, First said, noting that none of the buildings' filters, installed after the 2001 anthrax scare, showed ricin.
Still a team of investigators from the Capitol Police, FBI and Department of Homeland Security will send "hundreds of individuals" into the Senate office buildings over the next few days, Gainer said, to confiscate all unopened mail.
"Mail that was bundled and sitting on desks or envelopes that might be there," Gainer said, "we'll be taking those and getting those out of the various office buildings in the Capitol, while we simultaneously do some scientific analysis of the floors and desks and other approaches to ensure that those buildings are safe."
Senate Minority Leader Tom Daschle called the ricin either a terrorist or criminal act and declared that it "will not stop the work of the Senate or the Congress."
While the Capitol did remain open, much of the Senate's business was slowed or delayed yesterday. Most congressional staffers worked from home, while senators switched over to cramped historic office spaces in the Capitol that usually can accommodate no more than three people.
Unlike the anthrax scare, which closed only one office building, staffers this time were unable to share work space with other senators.
In 2001, Maryland Democratic Sen. Barbara A. Mikulski's staff took over a conference room offered by Republican Sen. Kay Bailey Hutchison of Texas while officials spent months undertaking the costly scrub down of the office building.
Maryland Sen. Paul S. Sarbanes moved into a conference room in the office of fellow Democratic Sen. Carl Levin of Michigan.
Yesterday, all the senators were out of luck.
"It's a little bit disruptive," said Mikulski spokeswoman Liz Poston, "but we're all trying to keep this business as usual. It's lessons learned during anthrax - laptops and cell phones."
Sun staff writer Scott Shane contributed to this article.