An investigation by the American Civil Liberties Union of Arizona found that more than 100 public charter schools have unlawful or discriminatory enrollment guidelines.

The civil rights group began investigating after it received multiple complaints from parents about their children not being admitted to charter schools, ACLU spokesman Steve Kilar said.

“We receive way more reports about charter school enrollment than we do about public schools in general, and that raised a red flag for us," Kilar said.

According to Kilar, the ACLU was only able to receive information from about 470 of the 546 charter schools, but found about half of them had discriminatory or illegal language in their enrollment documents, including six schools that capped enrollment for students with special needs.

The Arizona Charter Schools Association criticized the report. Its president and CEO, Eileen Sigmund, said public charter schools are open to “every Arizona family.”

“Contrary to the misleading allegations in this ACLU hit piece, enrollment data across charter schools demonstrate they are educating a student population that is increasingly diverse and represents Arizona students,” Sigmund stated.

Sigmund said the investigation is a clear attack as part of what she calls the ACLU’s “anti-charter agenda.”

EDITOR'S NOTE: This story has been modified to clarify the ACLU chapter.