A student was ordered to leave UC Riverside after police said they searched an on-campus apartment and found an assault rifle, five high-capacity magazines and a journal with hand-drawn images of a violent act.
The content of the drawings was not provided.
Police are submitting the case to the Riverside County district attorney to decide whether criminal charges will be pursued.
In the meantime, the student is on interim suspension and cannot return to campus pending the outcome of an administrative hearing.
Police discovered the weapon and ammunition Friday while executing a search warrant in the North District residential apartments after evidence surfaced of a weapon on campus.
Police said in a statement that the incident was unrelated to other campus events. The same day, the UC Riverside administration came to an agreement with pro-Palestinian protesters to shut down an encampment that was set up on the campus April 29.