CHICAGO (CBS) — More than 260 CPS employees will not be returning to their positions at Chicago Public Schools for the start of the new school year on Tuesday because their background checks were not cleared.

For those who did pass their background checks, some told CBS 2 Investigator Dorothy Tucker that the process made them feel like criminals.

Alison Eichhorn is grateful to be preparing her history lessons for the start of classes because she says a few days ago, she feared she would be nowhere near a classroom.

“August 23 I got an email that my background had not cleared,” Eichhorn said. “[I was] distraught. My first thought is I have to go back to work in four days and they’re telling me I might not be able to work with children.”

The email noted that Eichhorn had been arrested for criminal trespassing on February 4, 2016.

Eichhorn took part in a sit-in at Bank of America, ironically, in conjunction with a protest against CPS.

“Bank of America is immoral for what they’ve done to our schools,” she stated during the sit-in.

Eichhorn had to provide a certified deposition, a written explanation, and a police report which took her days to collect.

“I felt like I was being treated like a criminal,” she said.

CPS officials said it was important to investigate every arrest, no matter how small. As a result of the district’s massive background checks, 266 employees – including 57 teachers – will be barred from returning to classrooms because of serious allegations like child endangerment, sexual abuse, or drug distribution.

“There’s nothing with background checks,” said Eichhorn. “I just wish Chicago Public Schools would have treated us like professionals.”

“My records show that I have great reviews. I am a good teacher,” she added, claiming she felt providing the documentation was unnecessary.

In addition to the hundreds of CPS employees barred because of their backgrounds, another 245 cannot return because they did not get their fingerprints processed. CPS says many of those could be substitute teachers who haven’t checked their emails. School officials say they are still trying to reach them.