The video is jarring: A gray-haired woman tumbles, gets up to reach for her phone, held by police officers, and is yanked and taken to the ground. “Are you kidding me?” a bystander asks.
“What are they doing to her?” another adds.
Annelise Orleck, a labor historian who has taught at Dartmouth College for more than three decades, was at a protest for Palestinians in Gaza on Wednesday night, when she was knocked to the ground. Dr. Orleck, 65, was zip-tied and was one of 90 people who were arrested, according to the local police.
The professor walked away with a case of whiplash. But a short video clip of the episode flew around the internet, intensifying the debate over the relatively swift decision by Dartmouth’s president, Sian Leah Beilock, to call in police to arrest students and clear out an encampment.
Unlike other campuses where tents were tolerated for days, the police action at Dartmouth began a little more than two hours after the encampment first appeared, according to the college’s newspaper, The Dartmouth, and students who observed the events on Wednesday.
Dr. Beilock defended her decision.
“Last night, people felt so strongly about their beliefs that they were willing to face disciplinary action and arrest,” Ms. Beilock said in a message to campus on Thursday. “While there is bravery in that, part of choosing to engage in this way is not just acknowledging — but accepting — that actions have consequences.”
Dr. Beilock did not directly address the treatment of Dr. Orleck, who called the message “outrageous.”
“Her actions have consequences, too,” Dr. Orleck said in an interview. “The campus is in an uproar. Neither the students nor the faculty have been as radicalized in a long time as they’re feeling today.”
“I’ve been teaching here for 34 years,” she added. “There have been many protests, but I’ve never, ever seen riot police called to the green.” Dartmouth declined to comment on the incident.
How to handle the encampments has become a grinding challenge for university administrators. Earlier this month, the decision by Columbia University’s president to call in police stirred up protests at campuses across the country.
Demonstrations over the war in Gaza have led to at least 2,000 arrests over the last two weeks at universities across the country, according to a New York Times tally. The arrests have also angered some faculty, who have sometimes stepped in to try to help students.
The police in Hanover, N.H., the home of Dartmouth, said that the arrested included students and nonstudents, but did not provide a breakdown. The charges included criminal trespassing and resisting arrest. When the Hanover Police Department and the state police asked students to disperse, some did and others didn’t, police officials said.
It was unclear what disciplinary action, if any, the arrested students would face from the university.
Dr. Orleck said she was charged with criminal trespass and temporarily banned from campus, as a condition of her bail. The college’s administrators said on Thursday that the suspension was an error in the bail process, which they were working to fix.
In her message, Dr. Beilock strongly defended the decision to sweep away the encampment. And, she said, a key demand of protesters — that trustees vote on divestment from companies connected with Israel — violated the rules for making such decisions.
“Dartmouth’s endowment is not a political tool,” she said, “and using it to take sides on such a contested issue is an extraordinarily dangerous precedent to set.”
Dr. Orleck, who once served as the head of Jewish studies at the university, said she had watched with unease as police confrontations with student protesters escalated across the country.
She said she wanted to be at the Dartmouth protest because as an older Jewish professor — joined by many other older Jewish professors — her presence, she thought, could help keep her students safe.
As the police moved in, arresting students, Dr. Orleck said she started taking videos.
“I said to them, and I said it with some anger, ‘Leave our students alone. They’re students. They’re not criminals,’” she said. “The next thing I knew, I was rushed from the back.”
Messages left for the local and state police were not immediately returned.
One of the short viral videos begins with Dr. Orleck tumbling to the ground. She gets up. She moves toward an officer with her hand extended — grasping for her phone, she said. She is jerked and knocked down again. It is unclear what took place before the video begins.
Ivy Schweitzer, a recently retired English professor at the college, said the situation took a turn when campus security stepped back, and outside law enforcement moved in to make the arrests.
Dr. Orleck, she said, was recording the police with her phone.
“Annelise would never be physical with a police officer,” Dr. Schweitzer said. “But she would put her phone in their face, and I’m sure they wouldn’t like that.”
Jenna Russell contributed reporting. Sheelagh McNeill contributed research.
