The Door County Sheriff’s Office is investigating a threatening Twitter post by an anonymous user aimed at Black Lives Matter demonstrators in Sister Bay, Sheriff Tammy Sternard said Tuesday.

In the video, a man curses at demonstrators, makes the shape of a gun with his fingers and mimes shooting at them.

A threatening video was posted to Twitter Saturday and deleted Tuesday afternoon. It was taken from behind demonstrators during their Independence Day protest in downtown Sister Bay.

Sternard said she was made aware of the video Tuesday morning and that investigators from the Sheriff’s Office are looking into both the identity of the man in the video as well as whether a crime was committed.

“Any time we see any video regarding any potential threat, yes, we’re concerned,” Sternard said. A Facebook post from the Sheriff’s Office Tuesday afternoon said the office does not believe anyone is in danger.

“I saw myself, my mother and my brother in the video,” said Anya Kopischke, a demonstrator and Door County Black Lives Matter Solidarity organizer. (Disclosure: Kopischke is the child of Knock board member Alan Kopischke.) “It’s definitely uncomfortable and makes my blood boil, but after seeing what protesters across the country have faced, I’m honestly not surprised.”

The Twitter account that posted the video also has shared right-wing conspiracy theories and other messages threatening to harm or encouraging the harm of Black Lives Matter protesters via shooting, tear-gassing or running them over with vehicles. The user’s Twitter name spells “Trump fan” backwards.