Prosecutors have dropped assault charges against a college student with bipolar disorder who was shot in a Houston hospital room during a confrontation with two police officers moonlighting as security guards.

The two felony assault charges against the student, Alan Pean, 27, were dismissed on March 11 after a grand jury decided not to indict him, according to the Harris County district attorney’s office.

Mr. Pean was in the midst of a psychotic episode last August when he was admitted to St. Joseph Medical Center for minor injuries after an automobile accident in the hospital parking lot. A nurse later summoned security because he emerged naked into the hallway from his room and later refused to fasten his hospital gown. In an encounter with the patient, the officers stunned him with a Taser and shot him in the chest, the bullet nearly missing his heart. He survived after spending four days in intensive care.

The shooting was featured in a New York Times article last month about how hospitals are increasingly relying on armed guards, provoking debate among health care officials about whether the practice improves safety or risks harm to patients and staff.