The F.B.I.'s bumbling before 9/11 is water under the bridge. But the bureau's lackadaisical ineptitude in
pursuing the anthrax killer continues to threaten America's national security by permitting him to strike
again or, more likely, to flee to Iran or North Korea.

Almost everyone who has encountered the F.B.I. anthrax investigation is aghast at the bureau's lethargy. Some
in the biodefense community think they know a likely culprit, whom I'll call Mr. Z. Although the bureau has
polygraphed Mr. Z, searched his home twice and interviewed him four times, it has not placed him under
surveillance or asked its outside handwriting expert to compare his writing to that on the anthrax letters.

This is part of a larger pattern. Astonishingly, the F.B.I. allowed the destruction of anthrax stocks at Iowa State
University, losing what might have been valuable genetic clues. Then it waited until December to open the intact
anthrax envelope it found. The F.B.I. didn't obtain anthrax strains from various labs for comparison until March,
and the testing is still not complete. The bureau did not systematically polygraph scientists at two suspect labs,
Fort Detrick, Md., and Dugway Proving Ground in Utah, until a month ago.

Perhaps it's a cheap shot for an armchair detective to whine about the caution of dedicated and exceptionally
hard-working investigators. Yet months pass and the bureau continues to act like, well, a bureaucracy, plodding
along in slow motion. People in the biodefense field first gave Mr. Z's name to the bureau as a suspect in
October, and I wrote about him elliptically in a column on May 24.

He denies any wrongdoing, and his friends are heartsick at suspicions directed against a man they regard as a
patriot. Some of his polygraphs show evasion, I hear, although that may be because of his temperament.

If Mr. Z were an Arab national, he would have been imprisoned long ago. But he is a true-blue American with
close ties to the U.S. Defense Department, the C.I.A. and the American biodefense program. On the other
hand, he was once caught with a girlfriend in a biohazard "hot suite" at Fort Detrick, surrounded only by
blushing germs.

With many experts buzzing about Mr. Z behind his back, it's time for the F.B.I. to make a move: either it should
go after him more aggressively, sifting thoroughly through his past and picking up loose threads, or it should
seek to exculpate him and remove this cloud of suspicion.

Whoever sent the anthrax probably had no intention of killing people; the letters warned recipients to take
antibiotics. My guess is that the goal was to help America by raising preparedness against biological attacks in
the future.

So it seems fair to ask the F.B.I. a few questions:

Do you know how many identities and passports Mr. Z has and are you monitoring his international travel? I
have found at least one alias for him, and he has continued to travel abroad on government assignments, even to
Central Asia.

Why was his top security clearance suspended in August, less than a month before the anthrax attacks began?
This move left him infuriated. Are the C.I.A. and military intelligence agencies cooperating fully with the
investigation?

Have you searched the isolated residence that he had access to last fall? The F.B.I. has known about this
building, and knows that Mr. Z gave Cipro to people who visited it. This property and many others are legally
registered in the name of a friend of Mr. Z, but may be safe houses operated by American intelligence.

Have you examined whether Mr. Z has connections to the biggest anthrax outbreak among humans ever
recorded, the one that sickened more than 10,000 black farmers in Zimbabwe in 1978-80? There is evidence
that the anthrax was released by the white Rhodesian Army fighting against black guerrillas, and Mr. Z has
claimed that he participated in the white army's much-feared Selous Scouts. Could rogue elements of the
American military have backed the Rhodesian Army in anthrax and cholera attacks against blacks? Mr. Z's
résumé also claims involvement in the former South African Defense Force; all else aside, who knew that the
U.S. Defense Department would pick an American who had served in the armed forces of two white-racist
regimes to work in the American biodefense program with some of the world's deadliest germs?

What now? When do you shift into high gear?