Indiana University changed its policy a day before a protest. Then 33 people were arrested.

The day before Indiana University students planned to set up a pro-Palestine solidarity encampment on Dunn Meadow, a public field that's long been a site of gathering and protest in Bloomington, IU officials quietly changed its on-campus events policy to require tents and other "structures" to receive prior approval from the university.

The next day, 33 protesters at the encampment were arrested, shoved with riot shields and handcuffed with zip ties by Indiana State Police troopers who told them their use of camping tents and canopies on Dunn Meadow was unlawful.

Protesters say they were unaware of the policy change and many believe they were targeted by IU.

“The fact that they did it late at night, the night before they knew that this pro-Palestine event was scheduled to take place tells us that this was not about security,” said David McDonald, chair of the IU Department of Folklore and Ethnomusicology and one of those arrested. “It was about stifling speech on this particular issue.”

More on the Dunn Meadow protest:State police detain pro-Palestine protesters, tear down encampment at Indiana University

The change was approved by an ad-hoc committee of four, consisting of the IU chief of police, the vice provost for student life, the associate vice president of events and conferences and the vice president for undergraduate education. No faculty or students were involved in the committee.

On Thursday, hundreds of protesters refused to take down their encampment after IU Police Department and Indiana State Police officers told them the event was a violation of school policy. IUPD distributed pamphlets saying tents needed prior registration, but protesters disputed the claim, citing the Bloomington campus' policy on use of assembly grounds under an existing campus policy that's been in place since 1969,

As faculty and students attempted to explain the campus policy to troopers, state police Capt. Rob Priest replied, "I'm not arguing," and "I'm just following orders."

"If you resist us and stay, you're going to be arrested," Priest said. Less than three hours later, state police officers, many wearing full military gear and wielding riot-control equipment including rifles and riot shields, advanced on protesters and cuffed and arrested 33 protesters, three of whom were faculty members.

Banned from all IU-owned properties

All 33, the majority of them students, received the same penalty: a one-year ban from all IU-owned properties.

For freshman Elena Thomas, that meant she couldn't return to her dormitory after she was released from Monroe County Jail around 9 p.m. Thursday and had to stay the night at a friend's off-campus house. For IU senior Cameron Pierce it means he can't attend departmental graduation ceremonies or the commencement ceremony next week. For McDonald, it means he can't do his job.

An IU spokesperson said students and faculty are encouraged to appeal their bans with IUPD, saying the bans will be lifted through an appeals process in "nearly all cases."

Indiana University defended IUPD and state police actions Thursday, saying protesters violated "university free speech and events policies," noting that the revised outdoor policy was published online and at Dunn Meadow. But the students, faculty and community members who were arrested say those policies weren't clearly communicated to them by IU. They also say state police acted with disregard for protester safety and their First Amendment rights.

"There was no, 'This is new policy,'" said Chris Handwerger, an IU senior who was detained and banned from IU property. "There was no, 'This was changed last night.' It was just like, 'Nope, this is the policy, your policy's wrong.'"

"To be very clear, the students were never violent, and the troopers were absolutely brutal," McDonald said. "And this administration, which purports to hold students in high regard, has obviously demonstrated the opposite."

'You expect your kids to be protected when they're here'

As the arrests began Thursday, IU Palestine Solidarity Committee President Aidan Khamis grabbed a megaphone from inside the pro-Palestine encampment and shouted, "IU would rather brutalize its students than divest from genocide!"

Similar responses had been seen across the country, including at University of Texas at Austin, where state troopers were deployed to a pro-Palestine encampment and more than 50 were arrested. The week before at Columbia University in New York, more than 100 protesters were arrested.

A pro-Palestine encampment also happened at Purdue University in West Lafayette and the University of Notre Dame in South Bend. There were no arrests at either of those.

Around Indiana:Here's what happened at student protests this week over Gaza conflict

McDonald said he tried to stand between state police and protesters when the officers began advancing on the encampment and was hit in the ribs "four or five times" with a metal baton. Pierce said he and his wife were "dogpiled" by several officers and had "knees on the back of their spine" as they were rounded up with other cuffed protesters. Several detained protesters said their zip tie handcuffs, which remained on for several hours as detainees were taken to the Harry Gladstein Fieldhouse and then to Monroe County Jail, left bruises.

"I still have marks on my wrists because they were pretty tight," Handwerger said. "But there were a couple people where it was legitimately cutting off circulation pretty bad."

Detained protesters were loaded onto buses with IUPD officers after being cuffed by state police officers.

"It wasn't until I was at the courthouse, and had already been bound for three hours, that I was told what I was being charged with," Pierce said.

Dennis Thomas, the father of protester Elena Thomas, said he was disturbed by the state police using such force in response to seemingly lawful protests.

"You expect your kids to be protected when they're here," Thomas said. "I've always encouraged my daughters to stand up for what they feel is unjust to them, and you would think that these are things universities would want to protect and inspire in our future leaders."

IU says faculty, student appeals will likely result in lifted bans

At the Monroe County Jail, all 33 protesters were charged with criminal trespass, a Class A misdemeanor punishable by up to a year in jail and a $5,000 fine. Protesters were told that returning to campus could result in the charge being escalated to a Level 6 felony.

All of the charges against the 33 are preliminary and had not been filed by the prosecutor by the end of the day Friday. All of the protesters except one − a man charged with felony battery − were released sometime between 8 p.m. Thursday and 1 a.m. Friday.

As protesters left the jail, a crowd gathered in the nearby alleyway and cheered as they were released. Family and friends of the arrested offered to grab bikes and personal items for those who were banned from campus. People cracked jokes, traded contact information and waited on the pavement for their friends to be released.

"It feels like a humongous betrayal from the university," Pierce said. "I'm not surprised by their actions, but I guess I'm just surprised by how quickly they put together a plan, before the encampment even started, to shut down a peaceful protest."

"I have zero regrets," Handwerger said. "If I could do it over again, I'd do exactly the same."

H-T reporter Laura Lane contributed to this article.