EWING, N.J. — Searching for fresh leads in the anthrax investigation, the FBI has turned again to the public — and the nation's mail service — for help.
Federal authorities have asked the U.S. Postal Service to distribute an informational flier about the case to more than 500,000 people in New Jersey and Pennsylvania.
The bureau also doubled the reward Wednesday to $2.5 million for information leading to the capture of whoever sent the anthrax-tainted envelopes that terrorized the nation last year.
The fliers show pictures of the envelopes — each pre-stamped and smaller than business size. The FBI hopes someone will recognize the handwriting or the type of embossed, 34-cent envelope.
"We're reaching out to you to ensure there are no more victims," FBI agent Kevin Donovan said. "I don't believe this person is as elusive as the Unabomber."
Authorities declined Wednesday to reveal details about the probe.
The FBI is initially targeting the fliers to mail customers in the Trenton area because they suspect the culprit is comfortable there "due to present or prior association" with the area.
The fliers also suggest that the suspect or suspects likely have a scientific background or work history or "a specific familiarity with anthrax."
The tainted letters were postmarked in Trenton in September and October and went through the Hamilton mail facility. Officials believe several people were infected through cross-contamination in the mail.
Five people have died of anthrax since early October — including two Washington postal workers — and more than a dozen people were infected in New York, New Jersey, Florida and Washington.