Tuesday morning just before 7:30 a.m., a student at Princeton High School told a teacher that he saw an unidentified male in his 20s entered the school.
School officials decided that the students and staff should shelter in place as a precaution. Officials called the police, who searched the school looking for the man.
Police located the man, who was a Princeton High alumnus who came to visit the school unannounced. Police gave the all-clear and school operations are now normal.