Philadelphia, PA – A transgender woman was tackled by cops as she was trying to light a Thin Blue Line flag on fire in the middle of Philadelphia’s PRIDE celebration on Sunday.

Police arrested 18-year-old Ryan Segin at about 12:10 p.m. on June 10 when she pulled out a container of lighter fluid in the middle of a crowd watching the PRIDE parade.

The Philadelphia Inquirer explained that while flag burning itself is not illegal, Segin tried to douse the flag in fuel in the midst of a crowd of people, creating a very dangerous situation.

“It’s not an issue with the flag, the issue is being in a crowd of people and trying to pour lighter fluid on it,” a Philadelphia police spokesman said, according to NJ Advance Media. “It has nothing to do with the flag. It could have been paper.”

The Thin Blue Line flag is considered a sign of respect for fallen police officers, and represents the role law enforcement serves, standing between law-abiding citizens and criminals.

Thirty years ago, the U.S. Supreme Court ruled that burning an American flag is considered free speech and is not illegal.

However, if it’s done in a manner that risks harm to other people, it becomes illegal, according to Mary Catherine Roper, deputy legal director of the American Civil Liberties Union of Pennsylvania.

“Burning something in the middle of the crowd, she can be charged with endangering,” Roper told NJ Advance Media. “The First Amendment doesn’t protect her if she’s creating a dangerous situation.”

Roper explained that protesters like to burn flags at crowded events because the point is to be seen. However, they sometimes announce they’re going to burn the flag and create a space to do it in to make sure that nobody gets injured by their antics, she said and cited an example from the 2016 Democratic National Convention.

She also pointed out there are flag desecration laws in Pennsylvania, but Segin had not been charged with violating those, NJ Advance Media reported.

Police charged Segin with attempt to commit arson, risking a catastrophe, recklessly endangering another person, and related offenses, the Philadelphia Inquirer reported.

Philadelphia’s LGBT Affairs Director Amber Hikes posted on Facebook on Monday that she’d helped Segin’s father and other community organizers post bail.

She said that Segin had been sent to a male prison before she was bailed out, the Philadelphia Inquirer reported.