He has strongly denied that he had any role in the tainted letters.

Since shortly after the tainted letters to the senators were found, mail to Capitol Hill has been irradiated.

President Clinton has suggested the N.R.A. give the money raised from the tainted letter to the families of slain officers.

But investigators acknowledge that they still have no idea who is behind the tainted letters.

Still, the amount, typical of the tainted letters, was remarkably small - just 0.871 grams.

As the crow flies, Piscataway is 27 miles from Trenton, where the tainted letters were mailed.

But officials could not say how she was infected because no tainted letter or other vehicle for infection had been found.

Some speculated that there might be at least one other tainted letter.

For one thing, the tainted letters were apparently designed to affect only the mail recipients.

Meanwhile, the effort to collect and identify the tainted letters and the strains of anthrax that contaminated them has been maddeningly slow.