The trio – Ilene Poses, Lisa Haver and Barbara Dowdall – say the violations occurred during a Feb. 18 meeting at which commissioners voted on charter-school applications, according to the suit filed Tuesday in U.S. District Court in Philadelphia. The plaintiffs are members of the advocacy group Alliance for Philadelphia Public Schools.

The Feb. 18 meeting was contentious, with four people arrested on disorderly-conduct charges, and the plaintiffs were not allowed to display signs opposing new charter-school approvals, the suit says.

Representatives from charter operator KIPP, however, were allowed to distribute and wear T-shirts in support of KIPP schools, the suit says.

The suit also claims that a school police officer named as a defendant, John Augustine, illegally went into Haver’s shopping bag without permission and swiped all the protest signs inside.

“Without cause or justification, and at least in part in retaliation for the exercise of the plaintiff’s First Amendment rights and to chill the exercise of those rights, the defendants seized the plaintiffs, confiscated their signs and violated the plaintiffs’ liberty interests,” the suit says.

A school district spokeswoman said the district would not comment on…