BIDDEFORD, Maine — Someone painted the words "blood on her hands" in red on the sidewalk outside U.S. Sen. Susan Collins' Biddeford office overnight before Election Day, and poured more red paint nearby to look like a pool of blood, her campaign said.

Police said the vandalism happened around 11 p.m. Monday, according to WGME-TV coverage. Staffers found the sidewalk covered in red paint Tuesday morning, and some of the paint may have splattered onto the office's front doors, the Bangor Daily News reported, citing WMTW-TV.

The campaign said no one got into the building. Biddeford police are investigating.

"This is another incident in a series and the second attempt at our Biddeford office to intimidate the Senator and her staff," said Katie Brown, Collins' chief of staff. "These tactics are disturbing, but not effective."

The same Main Street office was vandalized in late September, when the words "Trump Whore" were spray-painted in red on its glass entry doors. Maine state Sen. Matt Harrington, R-Sanford, posted a photo of that message on X. After that incident, Brown said the senator and her staff "will not be intimidated" and that the office would stay open.

Collins' Democratic challenger, former Maine Senate President Troy Jackson, condemned the September vandalism, saying Collins and her staff "should be able to do their jobs without anyone defacing their office." No statement from Jackson on Tuesday's incident had been reported by midday.

The Bangor Daily News reported that Collins' Bangor home was egged about a week before the September vandalism, and that her offices received suspicious mailings a few weeks after it.

The Biddeford office sits a few blocks from where a man was fatally shot by an ICE agent in July. After that shooting, protesters marched to the office to demonstrate against Collins' support for ICE funding.

Collins, a Republican who has served in the Senate since 1997, is seeking a sixth term. Mainers are voting Tuesday.