1.   An employee at The New York Post became infected from a tainted letter mailed in Trenton.

2.   As more anthrax surfaced in U.S. post offices Friday, the FBI said that tainted letters sent to Washington and New York are likely the work of one man.

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

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

5.   Experts say the tainted letters are easy to detect, their effects easy to treat and their origins relatively easy to trace.

6.   How vulnerable are recipients of mail that passed through the same facilities as did the tainted letters?

7.   If the hijackers did have anthrax, they would probably have needed an accomplice to mail the tainted letters, said bioterrorism experts knowledgeable about the case.

8.   If the hijackers did have anthrax, they probably would have needed an accomplice to mail the tainted letters, according to bioterrorism experts knowledgeable about the case.

9.   In New York, an NBC employee was infected by a tainted letter sent from Trenton, N.J., FBI officials said Saturday.

10.   In New Jersey, state health spokeswoman Marilyn Riley said two Trenton postal employees who may have handled tainted letters were not infected with anthrax.