The threat was found written on a classroom desk last week.
Extra police were brought in to restrict access to the campus last Thursday and there was no incidents.
Police don't believe the student had the means to carry out the threat.
Montclair State police arrest student
For alleged threat
NEW JERSEY
An announcement on the school's Web site says campus police arrested Joseph Mastic of Fairview on Tuesday. The 18-year-old is free on bail, charged with making terroristic threats.
