CAROL COSTELLO, CNN ANCHOR: A new clue in the anthrax mystery. It comes in a New Jersey mailbox. It may be a critical link to finding out who sent some of last year's anthrax letters. CNN's Jeanne Meserve has the latest in the investigation.</s>JEANNE MESERVE, CNN CORRESPONDENT (voice-over): In an effort to determine where the anthrax letters were mailed, 600 samples were pulled from mailboxes in New Jersey, one from a mailbox that stood on this block in Princeton could give investigators a new lead.</s>GOV. JIM MCGREEVEY, NEW JERSEY: The environmental laboratories tested one sample out of the 600 samples positive for anthrax on the evening of August 8, 2002.</s>MESERVE: A U.S. Postal Inspection Service spokesman says because preliminary tests are not reliable, the mailbox is undergoing further testing at the Army's Aberdeen Proving Ground. The four anthrax letters all had Trenton, New Jersey postmarks and are believed to have gone through and contaminated a processing facility in Hamilton, New Jersey.</s>MCGREEVEY: The mailbox was reported part of the inflow to the Hamilton Postal Facility, not part of the outflow. Its contents, therefore, would not have been contaminated by the high speed mail sorting equipment that was believed to be the primary cause of the release of the anthrax spores that contaminated the Hamilton facility.</s>MESERVE: Scientists working with the FBI are doing genetic testing and fingerprinting to try to find other clues about the anthrax and where it came from, mindful, experts say, of the looming one year anniversary of the attacks.</s>ARMANDO LARA, FORMER FBI AGENT: There's a lot of pressure both externally and internally to solve this case, to indict, to prosecute and successfully convict the person or persons responsible for this anthrax.</s>MESERVE (on camera): Government sources deny that the FBI is operating under any artificial deadline. They say roughly 20 people are being looked at in connection with the investigation, but no arrests are imminent. Jean Meserve, CNN, Washington.
New Clue in Anthrax Mystery