Cornell University’s trustees announced on Thursday that they would investigate an April 30 incident in which the president, Michael Kotlikoff, bumped into students with his car after a debate over the conflict between Israelis and Palestinians.

A small group of students confronted Dr. Kotlikoff after he had spoken at the university event about free speech and the Middle East conflict. They posed questions about the suspension of pro-Palestinian student demonstrators in previous years, walking with him to his vehicle, a black Cadillac SUV.

After the students surrounded his vehicle, Dr. Kotlikoff got in, reversed and bumped one student. Another student said that his foot was run over. Emergency medical technicians arrived and checked the foot of that student, who was not seriously injured.

In an email to the campus on Thursday, the university said that an “ad hoc special committee” had been established to oversee the investigation of the events of that night. It said that Dr. Kotlikoff had recused himself from the investigation and “any related university decisions connected to the matter.”

The statement said that the trustees are “committed to ensuring a fair and thorough review guided by adherence to university policies and the best interests of the Cornell community.”

The event highlighted the lingering tensions on college campuses over the Israel-Hamas war, even as the large-scale protests from the spring of 2024 have dissipated.

Some student groups at Cornell have said that the university had unfairly disciplined pro-Palestinian students involved in the demonstrations.

One of the disciplined students was Momodou Taal, a Ph.D. student in Africana studies and a leader of the movement to establish protest encampments on the Ithaca, N.Y., campus. The Trump administration had sought to deport him and students at other universities whom it accused of spreading antisemitism.

Last week’s event, billed as a debate between supporters of the Palestinian cause and Israel, also featured Norman Finkelstein, a political scientist and author who spoke about Israel’s response to the Oct. 7, 2023, Hamas-led attacks on Israel.

The day after last week’s incident, Dr. Kotlikoff framed himself as the victim, asserting that students had harassed him and banged on his car. The students denied doing that, and video of the incident that the students supplied did not show them hitting the vehicle.

With few signs of progress on Mayor Zohran Mamdani’s promise to make New York City’s buses free for all riders, the City Council and some transit advocates are pushing for a more targeted alternative: focusing on the riders who need the help the most, now.

City officials are seeking to revamp an existing and underutilized city program called Fair Fares, which provides half-price subway and bus fares to low-income New Yorkers. Transit riders, advocates and elected officials have argued that in its current form, it excludes many of the roughly one million residents who qualify and need support.

Nodding to those concerns, Julie Menin, the Council speaker, said at a news conference on Wednesday that she supported plans to automatically enroll eligible lower-income New Yorkers into the program, and to make public transit completely free for them.

Fair Fares currently charges New Yorkers who make less than 150 percent of the federal poverty level half price — or $1.50 — to take bus, subway and paratransit rides. Individuals must make less than $23,500 a year to qualify; a family of four needs a household income of about $48,000 or less. Citizenship status is not considered.

Though nearly 380,000 New Yorkers receive the discount, about 575,000 more qualify for the program and do not take part. Supporters of the plans note the application process requires complicated paperwork that they say has stunted enrollment.

The City Council’s push comes as a number of transit advocacy groups have raised concerns about Mr. Mamdani’s free bus plan, which has been projected to cost nearly $1 billion a year, at a time when the city is facing a $5.4 billion budget deficit.

The Council proposals, in contrast, would be more targeted and cost less. The Fair Fares program, which began in 2019, currently costs the city less than $100 million a year. The proposals could more than double that price tag.

Mr. Mamdani’s office did not respond to requests for comment about the plans.

The mayor angered some advocates this year when he did not include funds in his preliminary budget to expand the Fair Fares program.

He has pitched free bus service as a public good, similar to libraries, that would benefit all New Yorkers, regardless of financial need.

Making buses free is key to Mr. Mamdani’s goal of making the fleet, one of the slowest in the nation, faster and more reliable. As an assemblyman, Mr. Mamdani championed a 2023 pilot program that made a select number of bus lines free. (Ridership increased, but the speed of service did not.)

Still, Mr. Mamdani’s plan faces challenges from Gov. Kathy Hochul, who could be vital to its funding. She has been unwilling to raise taxes on the rich at the scale proposed by Mr. Mamdani. And the Metropolitan Transportation Authority, the state agency that controls the city’s buses, has distanced itself from the plan, at a time when it is trying to crack down on fare evasion.

The lack of movement on the free bus plan has opened the door for more specific proposals from the City Council.

Ms. Menin, speaking at the news conference on Wednesday while surrounded by transit advocates on the steps of City Hall, said there was an urgent need to expand the program, amid a growing affordability crisis.

“People are literally forgoing meals because of this cost,” she said. “It is shameful.”

About one in five New Yorkers struggle to pay for public transit, a burden disproportionately borne by Black and Latino commuters and working mothers, according to a 2024 report from the Community Service Society of New York, an economic justice group.

Several transit advocacy groups are seeking more changes to the program.

The Citizens Budget Commission, a fiscal watchdog group that is skeptical of Mr. Mamdani’s free bus plan, said it instead supported raising the income limit for Fair Fares to 250 percent of the federal poverty level. That would include individuals making up to $39,900 a year, or a four-person household making $82,500.

At that threshold, two million New Yorkers would be eligible for the half-fare discount, and it would cover one in four working adults in the city, the group said.

Others want to make the program even more inclusive.

The Community Service Society has called for raising the income threshold to 300 percent of the poverty line, or about $99,000 for a family of four.

“It’s not capturing the real need,” said Rachel Swaner, a vice president at the organization, noting that there are many families who make marginally more than the current income limit. “They make too much to be eligible for public benefits, but they are really struggling to make ends meet.”

At the news conference on Wednesday, supporters of the Council’s proposals said the need for immediate economic relief was urgent.

For Dana Briggs, a 71-year-old Air Force veteran, it was only natural that he would join a September demonstration outside a Chicago detention center. He has regularly protested the Department of Homeland Security’s actions for more than a decade.

But this time, he would find himself inside a federal prison hours later. He said that while at the demonstration, he had been knocked to the ground by agents, swarmed and arrested, and had been taken to a hospital, where he was handcuffed to a bed. He was then transferred to the federal facility, and read his rights, fingerprinted and photographed.

So by the time Mr. Briggs was ordered to take a cotton swab and rub it against the inside of his cheek, he complied.

“If you refuse to give a swab, you’re committing another crime,” Mr. Briggs said in an interview. “I was unaware of that. And I suspect that 99.9 percent of us in this country are unaware of that.”

This week, Mr. Briggs became the lead plaintiff in a lawsuit against the federal government’s DNA collection practice, arguing that his arrest and the collection of his sample violated his rights to protest and protections against the government conducting “warrantless, unreasonable intrusions” into his body.

The lawsuit, filed in the Northern District of Illinois, names three other people as plaintiffs, two of whom were arrested but never charged with a crime.

“The government’s chilling message is clear,” the suit says. “If you protest government policies, we will arrest you, file away your DNA and monitor you — and potentially your biological relatives — going forward.”

In a directive issued last year, U.S. Customs and Border Protection said that people who are arrested by its officers or who are facing charges or convicted must provide DNA samples. According to the directive, the agency will not use force to collect DNA samples but may refer people for prosecution if they don’t cooperate.

In Mr. Briggs’s case, he was released two days after his arrest, and the charges against him were dismissed two months later. The cases of four other protesters who were arrested that day were also dismissed. A federal judge found that the government “swung and missed — multiple times” in charging Mr. Briggs.

But while Mr. Briggs was freed, his DNA sample remained in federal custody.

Last year, Georgetown Law’s Center on Privacy and Technology found that DNA samples were collected from about 2,000 U.S. citizens who were stopped at border checkpoints from October 2020 to December 2024. In some cases, the report found, the agency collected the DNA without stating a reason for doing so.

And that was before the Trump administration’s immigration crackdown.

During President Trump’s second term, federal deployments have swept through major cities, leading to a wave of protests and clashes between immigration agents and demonstrators. Many protesters have been arrested, and while some were not charged with a crime or have had their charges dismissed, their DNA samples have been collected and stored.

The lawsuit asks that the Homeland Security Department — the parent agency of Immigration and Customs Enforcement — be forced to follow a 2013 Supreme Court ruling that limited DNA collection to suspects arrested in connection with serious crimes.

“It puts you and your family in a surveillance state database of people who’ve criticized this administration,” said Carey R. Dunne, a founder of the Free + Fair Litigation Group, which represents Mr. Briggs. He called the government’s actions “a constellation of constitutional violations that needed to be challenged.”

Mr. Dunne and Mark F. Pomerantz, another founder of the litigation group, had led the Manhattan district attorney’s investigation into Mr. Trump’s business practices. They resigned in 2022 and, with a third founder, formed Free + Fair, a nonprofit law firm that aims to stem the tide of what it describes as anti-democratic policies in the United States.

The federal government’s DNA collection practice, on an “authoritarian scale of one to 10, this is a 10,” Mr. Dunne said. In a statement Wednesday evening, the Department of Homeland Security said that the agency is required under federal law to collect DNA samples. The Department of Justice did not responded to a request for comment.

In the decades since DNA was introduced as evidence in criminal cases, law enforcement agencies across the country have come to rely on it, particularly in solving cold cases.

DNA can be collected through an array of methods beyond swabs of saliva. In New York’s Gilgo Beach murder case, investigators used a sample from a discarded pizza crust to connect Rex Heuermann to four bodies found in 2010 on Long Island. Law enforcement agencies, including D.H.S. and the Police Department, have faced lawsuits over their DNA collection practices.

Over the span of about a month last year, the Trump administration launched a crackdown on illegal immigration in Chicago called Operation Midway Blitz. Throughout the operation, protesters gathered outside the Broadview ICE Detention Center facility, which had become the centerpiece of the administration’s crackdown.

On the morning of Sept. 27, Mr. Briggs left his home in Rockford, Ill., and traveled to Chicago to attend an Indigenous festival. On his way home, “appalled” by the administration’s actions, he stopped by the detention center.

About two hours after he arrived, a field commander yelled at the demonstrators to clear the streets, Mr. Briggs recalled. Seeing no people blocking the federal agents’ path, Mr. Briggs asked, “Why?”

“It was only about maybe eight to 10 seconds between the command to clear the streets and when I actually got knocked on the ground,” he said. “So even if I had wanted, I really didn’t have time or the energy at that point to actually get my butt off the streets.”

Video showed federal agents swarming Mr. Briggs and arresting him. He was taken inside the detention center for several hours before being transported to Loyola University Medical Center for medical treatment. At about 1 a.m., the agents took him to a federal facility, where he was read his Miranda rights, photographed, fingerprinted and ordered to provide a DNA sample.

The genetic material was sent to an F.B.I. database called CODIS that was created to gather information about convicted criminals and missing people and to assess evidence from crime scenes. According to the lawsuit, people who have been arrested are responsible for making sure their DNA is removed from the database when their charges are dismissed. Studies have shown that in most states, only a handful of DNA profiles added to the database have been expunged, the suit said.

In Mr. Briggs’s case, the lawsuit challenges the legality of collecting DNA from people arrested for “nonserious offenses.” The lawsuit also asserts that federal officials could use the DNA to draw inferences about people’s relatives, who did not consent or do anything wrong.

According to the lawsuit, the F.B.I. recently reported that the federal government had amassed about 27 million DNA profiles in a variety of cases and is collecting almost 150,000 DNA profiles monthly.

“I just find this to be abhorrent,” Mr. Briggs said. “If we don’t have a right to our own selves, everything is going to break down.”