A Manhattan judge on Thursday dismissed and sealed 30 criminal cases against students and staff at Columbia University who were accused of occupying a campus building during a demonstration against the Israel-Hamas war this past spring.

Nearly 300 people were arrested at protests at Columbia University and the City College of New York on April 30. While most were issued tickets and sent home, several dozen who faced more serious charges, including trespassing, were temporarily detained and faced prosecution in criminal court. Most Columbia protesters charged in criminal court appeared before a judge on Thursday.

Prosecutors charged more than 40 people with third-degree criminal trespass for allegedly breaking into and occupying Hamilton Hall, an academic building on Columbia’s Morningside Heights campus, in late April. One case against a student was already dismissed and another non-student defendant recently accepted a plea, according to the Manhattan district attorney’s office.

The DA’s office said in court that it lacked evidence, because surveillance cameras were covered almost immediately after protesters entered Hamilton Hall. Prosecutors said that no police officers were harmed during the arrests and that the students and staff whose cases were dismissed are already facing disciplinary proceedings.

A Columbia University official declined to comment but said disciplinary proceedings are ongoing.

More than a dozen protesters arrested at Columbia on April 30 who aren’t students or staff declined offers that would have dismissed their cases later, as long as they followed certain conditions. The defendants’ attorneys asked for their cases to be dismissed outright, as the students’ cases were.

The DA’s office is also continuing its prosecution of James Carlson, a protester accused of burning an Israeli flag on April 20, among other charges, according to court records. His defense attorney said in court that she disputed the validity of many of the allegations and added that Carlson declined an offer to complete a diversion program for one of the lesser charges. As she spoke, Carlson stood beside her with a keffiyeh — a traditional Palestinian woven headscarf — wrapped around his shoulders.

Supporters crowded the gallery of the second-floor Manhattan courtroom during the proceedings, which lasted less than 20 minutes. Many covered their faces with COVID-19 masks and wore keffiyehs. Afterwards, defendants whose cases were dismissed met with their attorneys while supporters decorated t-shirts, ate pizza and chanted “free Palestine” in a nearby park.

At a press conference across the street from the Lower Manhattan courthouse, a group criticized prosecutors for giving university-affiliated demonstrators offers that were different from those given to demonstrators who weren't affiliated with the university. They declined to share their names or say whether they were Columbia students.

At City College, where protesters were accused of occupying a campus building and throwing objects at police during their April 30 arrest, charges have already been dismissed against six students, according to DA Alvin Bragg's office. Several people not affiliated with the university declined plea deals, prosecutors said. Prosecutors are also still pursuing cases against several others arrested at City College, including five charged with assaulting police officers.

The NYPD and Mayor Eric Adams have defended police conduct during the mass arrests on college campuses this spring, while some advocates have raised concerns about the officers’ response. One officer accidentally fired a gun while searching a building at Columbia, though no one was hit. The NYPD and the DA's office are investigating the incident.