The Margaret Chase Smith Federal Building

The Burlington woman accused of mailing a threatening letter to U.S. Sen. Susan Collins waived a probable cause hearing on Tuesday and agreed to be held without bail while her case is pending in federal court in Bangor.

Suzanne E. Muscara, 37, allegedly mailed a letter to the Republican senator in October that contained a white powder that the sender claimed was anthrax. The letter came after Collins’ vote to confirm Brett Kavanaugh to the U.S. Supreme Court.

Muscara, who is being held at the Somerset County Jail in East Madison, last week requested the preliminary hearings before U.S. Magistrate Judge John Nivison but apparently changed her mind.

The letter, which was addressed to Collins at her Bangor home, was intercepted at the U.S. Postal Service’s sorting facility in Hampden on Oct. 17, two days after Collins’ husband received a similar letter in the mail.

Muscara was not charged in connection with the letter Collins’ husband, Thomas Daffron, received 10 days after the Republican senator announced her support for Kavanaugh.

No one has been charged with that mailing, according to the U.S. attorney’s office.

The second letter contained an Aetna Medicare Solutions colored flyer, the affidavit said. On one side in blue handwriting was written, “AnthRAX!!! HA HA HA!!!”

“A stick-figure face has been drawn with the letter ‘X’ for eyes, the tongue sticking out, and with ‘You’ and an arrow pointing at the stick figure face,” the affidavit said.

Muscara allegedly told investigators that she never expected the letter would be delivered or taken seriously.

The FBI was able to obtain a partial fingerprint from that envelope after determining the powder was starch. The fingerprint was matched to Muscara, the affidavit said. Her fingerprints were collected when she was arrested in 2013 in Pennsylvania. The circumstances surrounding that arrest were not included in court documents.

Muscara, who is a member of the Green Party, was arrested April 5. She has not been asked to enter a plea because she has not yet been indicted by a federal grand jury.

If convicted, Muscara faces up to 10 years in federal prison and a fine of up to $250,000.