Daniel C. Castillo was charged with two counts of unlawful sexual contact and trespassing.
Police say the female student was grabbed and fondled shortly before 4 p.m. Monday while walking near the intersection of South College Avenue and Kent Way in Newark.
She screamed, causing the attacker to run off, and then called 911. A search of the area led to the suspect, who was identified by the student.
Police say Castillo, who is an illegal immigrant, was given a warning last week after being found trespassing on campus.