At the University of Pennsylvania last fall, someone splattered red paint on a statue honoring Benjamin Franklin, the school’s founder.

Within hours, campus workers washed it off. But the university was eager to find the culprit.

A pro-Palestinian group had claimed responsibility on social media. The university examined footage and identified a student’s cellphone number using data from the campus Wi-Fi near the statue at the time it was vandalized. Campus police obtained a search warrant for T-Mobile’s call records for the phone, and later a warrant to seize the phone itself.

On Oct. 18 at 6 a.m., armed campus and city police appeared at the off-campus home of a student believed to be the phone’s owner. A neighbor said they shined lights into her bedroom window, holding guns. Then they entered the student’s apartment and seized his phone, according to a police filing.

Months later, the student has not been charged with any crime.

The Penn investigation, which remains open, is one of several across the country in which universities have turned to more sophisticated technology and shows of police force to investigate student vandalism and other property crimes related to pro-Palestinian demonstrations. (The student who had his phone seized did not respond to an interview request.)

Much of it happened even before President Trump returned to office. Since then, he has made clear he will use his power to force universities to take a hard line on protests. His administration has warned 60 universities that they could face penalties from investigations into antisemitism, and has also begun seeking to deport protesters. At least nine current or former students and one professor who were legally in the United States with visas or green cards have already been targeted, with at least one student being detained on the street by officials in plainclothes.