Charges have been dropped against three University of Arizona students who participated in a Border Patrol protest in March that went viral and became a lightning rod in the national discussion about campus free speech.

The Pima County Justice Court website shows court hearings set for this week for all three students were vacated after motions to dismiss criminal charges were granted Friday.

The website also lists the charges against all three students as "not referred for prosecution."

Two of the students were expected to appear in court in Pima County on Monday morning.

Denisse Moreno Melchor, a 20-year-old UA student, and Mariel Alexandra Bustamante, a 22-year-old student, were charged on April 1 with class 1 misdemeanors for interference with the peaceful conduct of an educational institution. Moreno Melchor also faced a second charge for threats and intimidation.

The third student was charged a few days later.

Marianna Ariel Coles-Curtis, a 27-year-old graduate student at the university, was charged with a class 1 misdemeanor for interference with the peaceful conduct of an educational institution. She was set to appear in court on Friday. (Coles-Curtis' first name appears as "Mirianna" on the court's website.)

Further details on why the charges were dropped were not immediately available on Sunday.

In a statement, UA said was aware of the Pima County Attorney's decision, but the university would continue its own investigation.

"We respect the decision and will continue to follow our processes and the law. The University is moving forward with the Dean of Students’ process review of the incident per our policies," UA said.

Social media accounts supporting the three students announced the change in the cases Sunday night. A Facebook event for a planned demonstration at the courthouse in Tucson was canceled.

Why the students were charged

The charges stemmed from a March 19 protest against Border Patrol agents on UA's Tucson campus. Video posted on social media of the March 19 incident showed two Border Patrol agents in a classroom giving a presentation, with people outside the door recording them and calling them "Murder Patrol," "murderers," and "an extension of the KKK."

But, at least initially, officers who responded to the scene did not even get the names of the students involved.

After the video spread among conservative media and social media accounts, the UA faced pressure to charge the students and cite them for violating the student code of conduct.

UA President Robert Robbins has defended the UA police chief's decision to charge the two students. He said the chief weighed a difficult decision, but that the students appeared to break the letter of the law.

Since the charges, the UA has seen large protests, which included demands for charges to be dropped and calls for Robbins to be fired.

The protests also have called attention to the broader issue of immigration enforcement officers' presence on college campuses. Protesters have said they want Border Patrol and Immigration and Customs Enforcement officers banned or at least limited from accessing campus.

On Tuesday, Robbins is scheduled to hold a "campus conversation" focused on "First Amendment rights, campus safety and the presence of Border Patrol on the UA campus." He called for the event in the wake of the protest and subsequent charges.

Reach reporter Rachel Leingang by email at rachel.leingang@gannett.com or by phone at 602-444-8157, or find her on Twitter and Facebook.

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