Jackson, who was among the second set of defendants charged in November 2017 following the recovery of deleted basement video, entered an open plea, meaning he has no assurance of a sentencing recommendation from the prosecution.
"National Hazing Prevention Week serves as a time for all members to recognize the importance of not hazing and how hazing has affected our community."
O'Brien had one count of hazing, two counts of unlawful acts relative to liquor, and one count of underage drinking bound over for trial.
The main goal of the coalition is to strengthen laws against hazing, namely upgrading the crime to felony status.
Michael Angelo Schiavone is the fourth former brother of Beta Theta Pi to plead guilty in the Tim Piazza case.
The Centre County judge assigned to oversee the trial for former Beta Theta Pi fraternity members has recused himself from the proceedings.