The spate of pro-Palestinian protests and encampments engulfed academic institutions of all sizes in nearly every part of the country.

As pro-Palestinian demonstrations rocked college campuses this spring with protests of the war in Gaza, many university administrators found themselves eager to quell the action however they could. Some negotiated with the demonstrators. Many sent in the police.

When Columbia University called in the police in April to break up an encampment, it was the first major detainment of protesters. Since then, more than 3,100 people have been arrested or detained on campuses across the country. Most were charged with trespassing or disturbing the peace. Some face more serious charges, like resisting arrest.

But in the months since, many of the charges have been dropped, even as some students are facing additional consequences, like being barred from their campuses or having their diplomas withheld.

Delia Garza, the prosecutor in Travis County who dropped criminal trespassing charges against more than 100 people arrested at the University of Texas at Austin, said that such charges were rarely a priority for prosecutors, since they are minor and nonviolent offenses. Ms. Garza, a Democrat, said she also calculated that jurors in her community would very likely determine that students protesting on their own campus were simply exercising First Amendment rights.

At some universities, the decision to drop the charges was met with disappointment. “Actions that violate laws and institutional rules should be met with consequences,” Mike Rosen, spokesman for the University of Texas at Austin, said.