The note was discovered Monday night by a student. The letter stated that a shooting will take place Wednesday at CSUN - which is the first day of finals. The note threatens to kill as many people as possible.
The note also threatens to kill professors and teachers for "making students depressed."
The note came to police attention at 10:44 p.m., according to CSUN Police Chief Anne P. Glavin.
Campus police are receiving assistance from the Los Angeles Police Department on the matter, and the investigation is in its early stages, Glavin said. CSUN police said it does not believe there is an "imminent threat" to the campus.
Regardless, school officials are taking precautions. Faculty members who are scheduled to give exams on Wednesday have been instructed to provide alternative examination options for their students that would not require students to be physically present on campus Wednesday, the university's president, Dianne F. Harrison, said at a press conference.
Harrison added that the campus will remain open on Wednesday based on the threat assessment and current information from police. She encouraged employees who are affected to contact their supervisor.
"Sadly, the world in which we live requires we take threats of violence and expressions of hate seriously - even when there is no evidence to suggest that the threatened acts are likely to materialize," Harrison said in an earlier statement.
The threat has students on edge.
"Every threat should be credible and taken into consideration and investigated and anything that can be done to stop it should be done, even if it's not real," said Denise King, a freshman.
King and her mother visited CSUN's police station Tuesday morning looking for answers, angry at the lack of information and worried about safety.
King's friends were at the Borderline Bar & Grill last month. She says she'll stay away from campus this week.
"I can't believe this is still continuing. They haven't found the source of where it's coming from. I just hope they find who it is. Luckily I don't have class for the rest of week, but I do have a lot of friends who will be here for the rest of the week on campus, so I hope everything is OK and everyone stays safe," said Preston Steinberg, a CSUN student.
RELATED: Mass shooting threat written inside bathroom at CSU Northridge sparks investigation
The note's discovery comes days after racist and anti-Semitic graffiti scrawled inside a campus bathroom was found. Last week, a student had discovered graffiti at Sierra Hall that read, "Mass shooting in Sierra Hall 12/12/18." A swastika was scrawled under the message.
Images of the graffiti circulated on social media and police vehicles were seen patrolling the campus at night.
Increased patrols on the campus were present Tuesday, with Harrison stating stepped-up law enforcement presence would continue as circumstances warranted.
"Though I am keenly aware some may object to an increase of police on our campus, it is my judgement that added law enforcement personnel is absolutely warranted," Harrison stated. "We need this measure of safety and reassurance at this time for our campus community."
The decision to keep the university open will be assessed daily, Harrison said.
Finals will be administered on campus after Wednesday.