Fake blood was thrown on a door outside Sen. Deb Fischer's downtown Lincoln office sometime Thursday night or Friday morning, police say.
Sgt. Kathy Phillips said an office employee discovered a substance resembling blood splattered on a door at Fischer's office, 440 N. Eighth St., at about 8:30 a.m. Friday.
A sticker belonging to Betsy Riot, a progressive protest group, was found on the door as well, Phillips said.
The vandalism comes a day after Fischer told reporters she plans to vote in favor of proceeding with Senate consideration of a Republican health care plan that would rewrite or replace the Affordable Care Act.
Fischer's office could not be reached for comment.
The office filed a belated report Friday about a similar incident in May. The front door and ground had what appeared to be bloody handprints and a hanger was on the front door. Capt. Michon Morrow said the incidents are likely related.
Police are investigating, and no citations or arrests have been made.