Dartmouth’s leader quickly called the police. The consequences were just as swift.

When police arrested student protesters at Dartmouth College, a 65-year-old professor ended up on the ground.

Two student journalists who reported that evening were eventually arrested themselves.

And a bystander, visiting his father, who lives near Dartmouth College, noticed he had a broken shoulder.

That was some of the collateral damage after Dartmouth College President Sian Leah Beilock took unusually quick action, authorizing police action on May 1 to clear an encampment that students had occupied on the college field just two hours earlier stored.

Dr. Beilock, a cognitive scientist who studies why people choke under pressure, has since become the scene of an outcry on campus.

Presidents have faced a series of unpalatable choices in dealing with the student camps that have recently sprung up across the country to protest Israel’s war in Gaza.

A few colleges, such as Northwestern University, reached agreements with their protesting students and were criticized for being too lenient. Others, such as Wesleyan University, said protesters would be punished but that officials would not use force to clear tents if students remained nonviolent.

And at places like the University of Chicago, administrators had warned about the camps and watched them grow for days before calling police.

Dartmouth College stood out for its almost immediate response to a nonviolent protest.

Students set up tents there around 6:45 PM, protectively surrounded by more than a hundred supporters, who linked their arms. After warnings to leave, campus safety officials turned it over to the Hanover Police Department, New Hampshire State Police and other local agencies. The arrests started around 8:50 pm

In an email the day after the arrests, Dr. Beilock said that allowing the university’s shared spaces to be taken over for ideological reasons “is at best exclusionary and at worst, as we have seen on other campuses in recent days, can quickly devolve into hateful harassment that makes Jewish students feel unsafe.”

Moshe L. Gray, the longtime executive director of the Dartmouth chapter of Chabad, an Orthodox Jewish group, said that Dr. Beilock has taken “a very principled stand” since Oct. 7, setting her apart from her Ivy League colleagues.

“She has a duty to keep this school safe,” Rabbi Gray said. “Jewish students feel like she has done that for them.”

But for some faculty members, deploying police to arrest nonviolent protesters violated the rules that should exist on university campuses.

“We are supposed to be a living example of how to deal with divisive issues, and the most important thing in this process is that we do not see each other as enemies,” says Udi Greenberg, professor of history. “Sending police on protesters is the exact opposite of addressing each other in good faith.”

There was also the issue of injuries.

Andrew Tefft, who was visiting his father from out of town, was taking a walk to the green when police entered. He said he had no ties to the college or the protesters, so when an officer ordered him to move, he was confused.

“I guess I was stupid enough to say, ‘Where?’” Mr. Tefft, 45, said in an interview. “I feel my phone being knocked out of my hands and flying away, and I feel my arms being pulled. I feel the metal shackles continue. I thought, ‘Oh, I’m going to get arrested.’”

He said he broke his shoulder during a fight with police. An arrest report said Mr. Tefft failed to comply with commands and behaved aggressively during the arrest.

“I grew up in this town,” said Mr. Tefft, who has fond memories of watching bonfires on the lawn, “and this is the craziest story that ever happened to me.”

Annelise Orleck, a former head of Jewish studies at the university, said she started making videos of the arrests when she was knocked to the ground as she tried to take her phone from a police officer.

Alesandra Gonzales, a student reporter, witnessed the professor’s arrest. Then she too was arrested. She called out to another student reporter, Charlotte Hampton, a news editor, who was also tied up with the cable. In an interview, both said they had press identification.

Local and provincial police officials did not agree to requests for questioning.

The last time so many campuses resorted to police to confront student protests was in 1970 during the anti-war movement, said David Farber, an American history professor at the University of Kansas who has studied the 1960s. Students were much more militarized then than they are now, he said, noting that they firebombed campus buildings across the country.

“What makes this period different is that there have been so many confrontations so quickly and so many drivers calling the police so quickly,” he said.

On May 6, Dr. tried Beilock explained her quick response during a noisy online meeting with teachers, where the limit of 500 participants was quickly reached.

“An ongoing encampment is not something we can guarantee the safety of,” she said, “especially if people outside of Dartmouth decide to join with their own agenda.” She cited Columbia University, where some outsiders had joined the protests but were certainly not the majority.

Many teachers were unhappy, saying the violence came from the police, not the protesters.

“Five tents,” Carolyn Dever, a former Dartmouth provost, wrote in the chat comments as Dr. Beilock spoke, a sentiment echoed by many faculty members.

“This isn’t Columbia,” wrote another faculty member.

“Drop the charges,” wrote another.

According to history professor Matthew J. Garcia, Dartmouth has used a big-city solution for the quiet, rural town of Hanover.

“It seems like a place outside of time,” he said, adding: “It is absurd to suggest that this is a hotbed of revolution.”

Also the student newspaper criticized the university in an editorialasking the university to urge authorities to drop charges against their reporters.

“The council should be ashamed,” the council said. “We expect a swift and public apology from college president Sian Leah Beilock.”

University officials initially responded defiantly, saying they supported the student reporters’ right to clear their names “through the legal process.”

But as backlash grew and supporters of press freedom criticized the university, Dr. Beilock adds: in a column in the student newspaper that the reporters should not have been arrested. “We are working with local authorities to ensure this error is corrected,” she wrote.

The charges against the reporters were dropped.

Some on campus may not be angry to call for her resignation. Perhaps as a measure of the high social costs of supporting Dr. Beilock, the student council publicly voted in favor of a no-confidence measure, 13 to 2, with three abstaining. After the student body president vetoed the public vote, citing insufficient consultation, a new vote, held privately, reversed the decision, 9-8 against, with two abstentions. The entire student population is now voting on a measure of no confidence.

The faculty is divided.

“Our president is Jewish himself and has been paying attention to how Jewish students feel on campus,” said Sergei Kan, a professor of anthropology. He said students at the protest chanted offensive, “anti-Semitic border” slogans such as “From the river to the sea, Palestine will be free.” (Many Palestinian supporters say the phrase is a rallying cry for Palestinian dignity.)

“When they surrounded the tents and held hands, they were ready for a fight,” Dr. Kan said, adding that the green “belongs to all of us.”

Dartmouth’s board has also supported the action. Liz Cahill Lempres, Dartmouth’s board chair, said in an email to The Times that she had spoken to all board members and that “everyone unequivocally supports” Dr. Beilock.

In any case, the arrests will not deter the demonstrators. Months before tents became a symbol of pro-Palestinian activism on college campuses nationwide, Kevin Engel and other students erected two outside the Dartmouth administration building to push for divestment from Israel.

Mr. Engel, a freshman, and another student were arrested on charges of trespassing, an early sign that Dr. Beilock was serious about cracking down on policy violators.

Dr. Beilock’s decision, Mr. Engel said, gave student activists a boost.

“We’re not going to stop,” he said. “Palestine will be free within our lifetime. The students take on the burden of that work because no one else does.”