Scranton, Pa. ? A Pennsylvania woman has been convicted of trying to mail anthrax hoax letters to government officials, including President Bush, at the height of last fall’s anthrax scare.

The hoax letters, which authorities say actually contained cornstarch, forced the closure of a post office in Nanticoke for several hours on Oct. 25. They also halted operations in the mail room at the Luzerne County Courthouse.

Rosemary Zavrel, 58, of Pittston, was convicted by a jury Friday of mailing threatening letters, aiding and abetting in mailing threatening letters and making false statements to the police.

Authorities said she and her former roommate, Emily Forman, mailed 17 letters filled with cornstarch to Bush, local judges and other authorities in an attempt to frame two teens who allegedly picked on Zavrel’s son.

The envelopes were marked with the return addresses of the two boys, authorities said.

Forman pleaded guilty in February to taking part in the crime. Zavrel is to be sentenced Oct. 10; the maximum sentence for each charge is five years in prison.

“The letters in this case were no joke. In that time in our history, each one of those letters was an evil, malicious threat,” Assistant U.S. Attorney Jack Garganus said.

Five people died and more than a dozen were sickened last fall after someone sent anthrax-laced letters through the mail to politicians and news organizations. No arrests have been made.