A Chicago Public Schools principal suddenly retired after she outraged parents by inviting an anti-police extremist to talk to students on “Career Day.”

Mary Beth Cunat personally invited the anti-police activist, Ethan Ethos, to speak to sixth through eighth-grade students at Wildwood Elementary School. Ethos is a self-described “radical” who routinely posts violent anti-police rhetoric online.

After a Chicago police commander was shot and killed execution-style in February, Ethos posted online, “F HIM [and] HIS FAMILY.”

Ethos also posts the term “CPDK” which apparently stands for “Chicago Police Department Killer.” The extremist referred to cops as “pigs” and once posted about killing rich people.

Ethos apparently has shown hatred for police because he claimed a Chicago police officer murdered his friend with a stun gun.

In an apology letter to parents, Cunat wrote that she brought in Ethos to talk to students about his poetry and civic work, but things went off the rails.

“He told them all the police are bad and all the police wanted to kill people,” said Linda Ricciardi, who had three children listen to Ethos on career day. “I was very disappointed that someone would come into this school and preach hate about the police. Or, even if he was talking about someone else, I would still be upset.”

Mary Beth Cunat wrote a letter of apology before retiring, writing in part, “I was present when his narrative took a negative turn about policing, at which point I immediately intervened... I care about your children and would never intentionally expose them to or endorse this type of negativity.”

Some parents including Ricciardi disputed that Cunat immediately intervened, saying Ethos spoke to a few classrooms without interruption.

Some of the parents also said Cunat brought in Ethos because she recently had been pressured to introduce anti-police philosophies to students.

Nearly every parent who talked to Fox News said the principal was doing an excellent job at the school, which is one of Chicago’s top-performing, but she made a grave mistake.

One Chicago police officer, Fernando Flores, who lives nearby and had children who went to the school, said Ethos speaking to students was part of a broader indoctrination.

“Insulted. Angry. I can't believe she didn't vet him properly. Look on his Facebook account,” Flores said. “Some of the things on his account are absolutely horrible.”

Ethan Ethos declined Fox News’ request for an interview.

The Chicago School District wrote in an email that it did not know of or approve Ethos speaking to students.

Cunat said in a brief phone conversation that she did not resign, but retired. Her letter to parents said in part that she was retiring to spend time with family.