BANGOR, Maine — Jury selection begins Tuesday for a woman charged with mailing a threatening letter with white powder to Sen. Susan Collins' home in Bangor last year. 

Suzanne Muscara, 37, of Burlington, is officially charged with mailing a threatening communication to a U.S. government official protected under federal law when she allegedly sent the letter in October 2018.  

Muscara pleaded not guilty in federal court to the charges back in April. 

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

RELATED: 'I acted with integrity' -- Collins stands behind Kavanaugh vote following book release

Thomas Daffron, Collns' husband, opened a letter at their Bangor home on October 15. The letter claimed to be poisoned with ricin. Authorities and hazardous material experts were called to the home but determined that the letter did not contain the poison. Senator Collins' office says the individual(s) who sent the October 15 letter has not been found as of a year later.

Two days after the letter arrived at Sen. Collins Bangor home, the U.S. Postal Service intercepted another letter leaking white powder bound for the Collins home because they had started screening the Senator's mail. This letter claimed to be carrying anthrax.  Muscara's fingerprints were found on the envelope and she later told FBI agents she had sent it but that it did not contain any poison. 

The letters were sent to Collins' home when the Maine Senator was under a lot of scrutiny by people who wanted her to take a public stance against then-Supreme Court nominee Brett Kavanaugh. Kavanaugh was accused by several women of sexual assault but eventually did garner Collins' support.

Muscara's trial is expected to begin on November 4. 

RELATED: Woman charged with mail threat to Collins home appears in court