Anthrax, Investigation of 2001 Murders

The 2001 anthrax letter attacks brought the first known deaths ever caused by bioterrorism in the United States. The fear that subsequently paralyzed the nation focused attention on the new field of microbial forensics, which is responsible not only for tracing outbreaks of microbial diseases but also on collecting data that must meet legal standards for evidence .

The anthrax attacks began with the illness of Robert Stevens, a sixty-three year old British immigrant employed as a photo editor at the Sun, a supermarket tabloid newspaper published by American Media, Inc. in Boca Raton, Florida. Stevens became ill on September 29 while vacationing with his wife inNorth Carolina. Initially, he felt fatigued and weak. Later, he became feverish and had trouble breathing. He then began vomiting and became delirious. Stevens, having driven home, was admitted on October 2 to JFK Medical Center in the West Palm Beach, Florida suburb of Atlantis. The presumptive diagnosis was meningitis, an inflammation of the membrane covering the brain.

In the United States, only eighteen cases of anthrax from inhaled spores were recorded in the twentieth century. Despite the rarity of anthrax, Stevens' physician, Dr. Larry Bush, suspected the bacteria. He had a sample of Stevens' blood sent to Anne Beall, the lead medical technologist at Integrated Regional Laboratories in Ft. Lauderdale. To detect anthrax, Beall conducted a series of tests. She first determined the motility of the bacteria or whether they were capable of spontaneous movement. Motility can be observed through the microscope or, occasionally, through the spread of growth in a culture medium. Beall then checked the action of the bacteria upon red blood cells. When placed in a medium containing red blood cells, some bacteria destroy the cells in a process called hemolysis. The tests took hours to complete because quantities of bacteria had to first be grown for the procedures. The bacteria taken from Stevens were nonmotile and nonhemolytic. These are characteristics of anthrax bacteria.

In 1999, the Centers for Disease Control established a bioterrorism preparedness and response program. The Florida State Laboratory in Jacksonville, part of the CDC network, received the Stevens' samples according to protocol. Dr. Philip Lee, Florida's biological defense coordinator, examined the bacteria according to CDC procedures for suspected anthrax.

Lee conducted three tests: capsular staining, a polysaccharide test of the cell wall, and a gamma phage test. Capsular staining identifies whether the bacillus has a capsule, a thick outer coating. The test by itself is not conclusive for anthrax because some other bacteria are also encased in capsules. The polysaccharide test checks to see whether the cell wall contains a specific sign, a polysaccharide, which is specific to anthrax and a few other bacteria. A positive result is not a confirmation of anthrax. However, if both the capsular and polysaccharide tests are positive, the bacteria are almost certainly anthrax. The gamma phage test is based on the knowledge that certain viruses, known as phages, can enter and infect bacteria. A gamma phage can infect anthrax. The test involves introducing gamma phages to suspected anthrax. If the bacterial cells split open, or lyse, they are virtually certain to be anthrax. All three tests indicated anthrax.

With anthrax confirmed, the CDC needed to determine how Stevens became exposed to the bacteria and to identify other possible cases. Stevens, who died on October 5, never recovered sufficiently to assist in the investigation. Investigators initially suspected that he had encountered anthrax, which typically strikes animals, by drinking from a stream in North Carolina. CDC-organized teams of federal, state, and local investigators interviewed people, swabbed surfaces, and collected samples for testing at the places where Stevens worked, lived, shopped, fished, hiked, and visited in Florida and North Carolina.

At this point, American Media employees recalled that a mailroom clerk had gone home sick with symptoms similar to those of Stevens. The clerk had entered a Miami hospital on October 1 and had received large doses of the antibiotic ciprofloxacin or Cipro. The clerk survived. Cipro, more than any other antibiotic, is effective against a large variety of anthrax strains.

Preliminary testing indicated that Bacillus anthracis was present in samples taken from the American Media building where Stevens worked and the computer keyboard that he used. There was no reason why anthrax should be present in these areas. Investigators concluded that Stevens had been deliberately exposed. Jean Malecki, director of the Palm Beach County Health Department, ordered the American Media building closed. It has never reopened. About 1,000 people who were considered at risk of developing anthrax by being present in the building some time since August 1 had their nostrils swabbed to test for the presence of anthrax, and were given a ten-day supply of antibiotics .

The ill mailroom clerk indicated the mode of transmission of anthrax into the American Media building. Some Sun employees recalled a trifolded letter containing powder and a small, plastic, gold-colored Star of David charm. They were uncertain of the text of the letter. Stevens had taken the letter and sat down at his keyboard with it on September 19.

On October 15, the Florida Department of Health announced that anthrax had been found in the Boca Raton post office. Spores were found in an area where mail was sorted for pickup by American Media.

Meanwhile, an NBC employee in New York City received a diagnosis of cutaneous anthrax (anthrax lesions of the skin) on October 12. By October 25, nasal swabs had been taken from 2,580 people inNew York City and preventive Cipro had been given to 1,306. All seven confirmed cases were connected to the media: two at NBC, three at the New York Post, and one each at ABC and CBS.

Health authorities recovered the letter sent to NBC. Addressed to anchorman Tom Brokaw, it contained hand-printed capital letters that stated, "This is next. Take precautions now. Death to America. Death to Israel. Allah is Great." Three other anthrax letters were later found and all were postmarked Trenton, New Jersey, the imprint made at the large postal sorting and distribution center on Route 130 in Hamilton Township, ten miles from Princeton. Investigators swabbed 561 mailboxes and delivered the cotton tips to state laboratories. Only one mailbox, on a street corner in Princeton, tested positive for anthrax.

On October 15, anthrax was found in letters sent to prominent U.S. Senators Tom Daschle (D-South Dakota) and Russell Feingold (D-Wisconsin). Twenty members of Daschle's staff were exposed, as were two Feingold workers and six responders from the Capitol Hill Police. The Hart Office Building, home to Daschle and Feingold, was ordered closed on October 16 and would not open again until January 2002, when decontamination had been completed. The Capitol and all five remaining Congressional office buildings were also closed for screening. In subsequent weeks, suspicions of anthrax prompted closings throughout the Washington, D.C. area, including parts of the Federal Reserve Building, the U.S. Supreme Court, the Pentagon, and the State Department.

The mail processing facility that served Congress is located on Brentwood Road in Washington, D.C. Four of the Brentwood employees became ill with inhalation anthrax and two died. In a postal center, anthrax spores might settle not only in the nasal passages or skin of workers but also on sorting machines and other mail. Each newly infected piece of mail could become a potential anthrax carrier. Inhalation anthrax, apparently spread through cross-contaminated mail, killed Kathy Nguyen, a Vietnamese immigrant hospital supply worker in Manhattan on October 31 and Ottilie Lundgren, an elderly rural Connecticut woman on November 21.

Naming the anthrax investigation "Amerithrax," the Federal Bureau of Investigation released a profile of the suspect on November 9. According to the FBI , the anthrax mailer was likely an adult male with a scientific background or a strong interest in science. He had access to a source of anthrax, knew how to refine it, and had familiarity with the Trenton, New Jersey area. A non-confrontational person and a loner, the mailer probably tended to hold grudges for a long time.

Some scientists and journalists publicly speculated that the anthrax mailer had ties to the government since anthrax is not easy to obtain. The anthrax that had been discovered in the New York City and Washington, D.C. letters belonged to the Ames strain of anthrax. First acquired by the U.S. army for vaccine research at Fort Detrick, Maryland, Ames anthrax was discovered when it infected some cows in Texas in 1981. When samples were later sent to other military and civilian labs, the strain was named "Ames" after the return address label of a government lab in Ames, Iowa. Some samples of the Ames strain were sent to allies overseas, including one batch that went to the British biological defense establishment at Porton Down.

The timing of the anthrax attacks, right after the September 11 terrorist attacks on the Pentagon and World Trade Center, also raised suspicions that foreign terrorists were responsible. Two of the September 11 hijackers had lived in South Florida, not far from American Media headquarters, and one was reportedly treated for cutaneous anthrax. The FBI, preferring the theory of a lone domestic terrorist, continues to pursue leads as of 2005.

see also Anthrax; Antibiotics; Bacterial biology; Bacteria, classification; Biological weapons, genetic identification; Bioterrorism; Criminal profiling; Cross contamination; FBI (United States Federal Bureau of Investigation); Mail sanitization; September 11, 2001, terrorist attacks (forensic investigations of).