PITTSBURGH — A religious liberties law firm has sued on behalf of a public school teacher's aide who was suspended without pay for a year for wearing a cross necklace.

Brenda Nichol, 43, of Glen Campbell, sued ARIN Intermediate Unit 28 in federal court in Pittsburgh yesterday, saying the agency's rule violates her First Amendment right to freedom of religious expression.

The agency prohibits all employees from wearing religious garb, including crosses. Officials say the rule is based on an 1895 state law.

But Vincent McCarthy, senior counsel for the American Center for Law and Justice, says the ban is unconstitutional.

"The law is very clear on this issue — school personnel do not shed their constitutional freedoms when they enter the schoolhouse door," McCarthy said. The Virginia-based public-interest law firm was founded in 1990 by Christian broadcaster Pat Robertson.

Nichol was suspended April 8 when she refused to take off or cover up the 1 1/4-inch cross she wears an average of three to five times a week.

The agency supplies teachers aides and other services to 11 public school districts in Armstrong and Indiana counties, including the Penns Manor School District about 45 miles northeast of Pittsburgh, where Nichol worked.

Nichol said employees were told of the ban as far back as 1997, but that other teachers routinely wore crosses and other religious items, until March. Since then, Nichol was warned twice about wearing the necklace. Under the Pennsylvania School Code, she could be fired for a second offense.

Nichol said she doesn't know why ARIN officials decided to press the issue.

The agency's executive director, Robert H. Coad Jr., said he couldn't talk specifically about Nichol's employment status. But, he said, "a public school entity ... doesn't generally go looking for trouble unless they get a complaint."

Coad said the measure was meant to keep employees from wearing any item that could be objectionable to others, including symbols or emblems of occult religions.

"I don't feel I need to wear it every single day to be a Christian. It's not what makes me a Christian," Nichol said. But she believes in the biblical injunction that Jesus will deny earthly followers if they deny their belief in him.

Nichol sued ARIN, Coad and two other supervisors involved in the decision to suspend her. The other supervisors didn't immediately return calls for comment.

Nichol says she wants U.S. District Judge Arthur Schwab to order her back to work until he decides the merits of her case. A hearing date wasn't immediately set.

The lawsuit states Nichol is seeking only nominal damages, and the 43-year-old mother of three was teary-eyed as she explained why the necklace is important to her.

"I really do love my job, but I love the Lord the most," Nichol said.

McCarthy says he believes the agency's employee code is the problem, because it covers all employees even though the state law prohibits only teachers from wearing "religious garb" in schools.

"We're challenging the ARIN code and, if for some reason the court would uphold that code, then we'd fight the state statute as well," McCarthy said.

Coad said the state law was upheld by the 3rd U.S. Circuit Court of Appeals.

In that 1990 case, the court rejected arguments by a Muslim teacher from Philadelphia who sought to wear traditional garb, saying "the preservation of religious neutrality (in public schools) is a compelling state interest."

But McCarthy said judges in the 3rd Circuit opinion also spoke favorably of an Oregon Supreme Court decision, which held that certain religious symbols — like crosses and Stars of David — are permissible.