A Canadian teenager accused of making a phony bomb threat to Princeton University last year has pleaded guilty to creating a false public alarm and was sentenced to two years of probation.

The 16-year-old boy entered his plea Friday, according to the Mercer County Prosecutor’s Office. It was made public on Tuesday.

The boy, who was 15 years old at the time, called the Princeton University Department of Public Safety on Sept. 19, and said he had placed improvised explosive devices in a least four locations, including the school’s art museum, chapel, main library and Nassau Hall.

The campus was largely empty at the time.

AP wire services helped contribute to this report.